MICHAEL J. COWLEYAcademic Profile
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ABOUT

PERSONAL DETAILS
37 Sinnathamby Blvd, Springfield Central QLD 4300
michael.cowley@usq.edu.au
0468 321 750
Hello. I am a Lecturer a Scientist a Programmer an Engineer
I am passionate about researching and promoting physics
Welcome to my Academic profile
Available as a consultant

MY

BIOGRAPHY

I am a research scientist who has worked in various scientific fields, including astrophysics, lightning physics, medical physics, and physics education. I have contributed to over 30 published papers in numerous international peer-reviewed journals, which have been cited over 500 times. In addition to my research, I have a keen interest in teaching and outreach, having prepared and delivered numerous lectures, educational seminars, professional development courses, and public talks.

I completed my PhD at Macquarie University and the Australian Astronomical Observatory, where I researched The Evolutionary Impact of Supermassive Black Holes on their Host Galaxies. My undergraduate studies were performed at the Queensland University of Technology, where I achieved first-class Honours in astrophysics. My Honours thesis was on The Detection, observation and characterisation of transiting objects via the Kepler telescope. I continue my research with collaborators on TAIPAN, ZFOURGE and ZFIRE, which are extragalactic surveys tasked with studying the physical processes related to the formation and evolution of galaxies.

I am currently an adjunct lecturer at the University of Southern Queensland, a science liaison for CSIRO's Scientists in Schools program, a member of the ASA's Education and Public Outreach Chapter, a member of the IAU Working Group on Theory and Methods in Astronomy Education, a scientific consultant to the lighting industry, and an education content developer for Macquarie University, where I design and develop STEM (Science, Technology, Engineering and Mathematics) modules and professional development courses for teachers.

Before my academic career, I spent a little over a decade in the finance industry, working as a broker, analyst and product manager.

FIELD OF

RESEARCH

  • Galaxy Formation and Evolution
  • Galaxy Environment
  • Star Formation
  • Supermassive Blackholes
  • Multi-wavelength Photometry
  • Infrared Spectroscopy
  • Spectral Energy Distribution Modeling
  • Physics Education
  • Lighting Physics

PUBLICATION

RECORD

  • Citations: 587
  • H-Index: 15
  • 33 papers (as at 12/2018) in refereed journals:
    • Monthly Notices of the Royal Astronomical Society
    • Astrophysical Journal
    • European Journal of Physics
    • Publications of the Astronomical Society of Australia
    • Physics Education

PROFESSIONAL

SOCITIES & SERVICES

  • Present:
    • Referee for the European Journal of Physics
    • Member of the galaxy survey, TAIPAN
    • Member of the galaxy survey, ZFIRE
    • Member of the galaxy survey, ZFOURGE
    • Member of the Astronomical Society of Australia
    • Member of the Australian Institute of Physics
    • Member of the Institute of Physics
    • Member of the IAU Working Group on Astronomy Education
    • Member of the ASA Education and Public Outreach Chapter
  • Past:
    • Member of Siding Spring Time Allocation Committee
    • Member of the galaxy survey, TAIPAN
    • Member for Macquarie University Faculty of Science Discipline Committee
    • Member for Macquarie University Dept. of Physics Diversity Committee
    • Member of the Astronomical Association of Queensland (AAQ)
    • Member of the American Association for the Advancement of Science


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RESUME

  • EDUCATION
  • 2017
    2014
    Sydney

    PH.D. PHYSICS AND ASTRONOMY

    MACQUARIE UNIVERSITY / AUSTRALIAN ASTRONOMICAL OBSERVATORY

    Supervisors: Dr. Lee Spitler, Dr. Richard McDermid, and Prof. Andrew Hopkins Project: The Evolutionary Impact of Supermassive Black Holes on Their Host Galaxies. Committees: Member of Faculty Discipline Committee, Member of Department Diversity Committee, Member of the Time Allocation Committee for the Siding Spring Telescope
  • 2013
    2012
    Brisbane

    HONOURS (FIRST CLASS) ASTROPHYSICS

    QUEENSLAND UNIVERSITY OF TECHNOLOGY

    Supervisor: Dr. Stephen Hughes Project: The Detection, Observation and Characterisation of Transiting Objects via Kepler Societies: Physics Society
  • 2012
    2006
    Brisbane

    BACHELORS (DISTINCTION) ASTROPHYSICS

    QUEENSLAND UNIVERSITY OF TECHNOLOGY

    Societies: Physics Society
  • 2001
    Warrnambool

    CERTIFICATE MANAGEMENT

    SOUTH WEST INSTITUTE OF TAFE

  • ACADEMIC AND PROFESSIONAL POSITIONS
  • NOW
    2016
    Sydney

    EDUCATION CONTENT DEVELOPER

    MACQUARIE UNIVERSITY

    Responsibilities include designing, developing, and delivering NESA (NSW Education Standards Authority) accredited professional development courses for school teachers.
  • NOW
    2017
    Brisbane

    SCIENTIFIC CONSULTANT

    LIGHT HARMONY CONSULTANTS

    Responsibilities include providing consultation in the areas of photometry & lighting, and expert witness reports & testimony on issues regarding lighting physics.
  • 2016
    2014
    Sydney

    RESEARCH OFFICER

    MACQUARIE UNIVERSITY

    Responsibilities included designing and developing STEM (Science, Technology, Engineering and Mathematics) modules for the Government led initiative, Opening Real Science.
  • 2013
    2011
    Brisbane

    RESEARCH ASSISTANT

    QUEENSLAND UNIVERSITY OF TECHNOLOGY

    Responsibilities included assisting with research activities on the study of health implications of workspace lighting in tropical regions.
  • 2011
    2010
    Brisbane

    BROKER RELATIONSHIP MANAGER

    SUNCORP METWAY

    Responsibilities included developing and growing business relationships with the bank's intermediaries.
  • 2010
    2009
    Brisbane

    PRODUCT MANAGER

    SUNCORP METWAY

    Responsibilities included ownership of the balance sheet and life cycle management of several business product portfolios, including international trade, debtor finance, equipment finance, and business credit cards.
  • 2009
    2008
    Brisbane

    TEAM LEADER

    SUNCORP METWAY ADVANCES CORPORATION

    Responsibilities included the recruitment, induction and supervision of support staff.
  • 2008
    2003
    Brisbane

    CREDIT ANALYST

    SUNCORP METWAY ADVANCES CORPORATION

    Responsibilities included the analysis of client credit data and financial statements to forecast credit risks.
  • 2003
    2002
    Brisbane

    FINANCE BROKER

    BUSINESS FINANCE AND LEASING

    Responsibilities included the brokering of commercial and equipment finance for clients.
  • 2002
    2001
    Brisbane

    BUSINESS DEVELOPMENT MANAGER

    ELECTRONIC BANKING SOLUTIONS

    Responsibilities included the brokering of merchant facilities for clients.
  • 2001
    1997
    Brisbane

    AREA SALES MANAGER

    TARGET AUSTRALIA

    Responsibilities included managing assigned departments and for staff.
  • SCHOLARSHIPS AND AWARDS
  • 2015
    Sydney

    POSTGRADUATE EXCELLENCE IN PHYSICS

    AUSTRALIAN INSTITUTE OF PHYSICS

  • 2015
    Sydney

    MQAAASTRO OBSERVING FUNDING AWARD

    MACQUARIE UNIVERSITY

  • 2015
    Sydney

    POST GRADUATE RESEARCH FUNDING AWARD

    MACQUARIE UNIVERSITY

  • 2014
    Sydney

    TREVOR BURGESS SCHOLARSHIP

    AUSTRALIAN ASTRONOMICAL OBSERVATORY

  • 2014
    Sydney

    RESEARCH EXCELLENCE SCHOLARSHIP

    MACQUARIE UNIVERSITY

  • 2012
    Brisbane

    EXPERIMENTAL PHYSICS PRIZE

    QUEENSLAND UNIVERSITY OF TECHNOLOGY

  • 2011
    Brisbane

    VACATION RESEARCH SCHOLARSHIP

    QUEENSLAND UNIVERSITY OF TECHNOLOGY

  • 2010
    Brisbane

    DESIGN & EXECUTION EXCELLENCE AWARD

    SUNCORP BANK

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TEACHING

  • CURRENT POSITION
  • NOW
    2018

    ADJUNCT LECTURER

    UNIVERSITY OF SOUTHERN QUEENSLAND

    Responsibilities include preparing and conducting lectures for the School of Agricultural, Computational and Environmental Sciences in their unit, Optical Physics (PHY2207).
  • TEACHING HISTORY
  • 2017

    GUEST LECTURER

    MACQUARIE UNIVERSITY

    Responsibilities included preparing and delivering a guest lecture for the Department of Educational Studies in their unit, Science: Today and Tomorrow (EDUC109).
  • 2016

    GUEST LECTURER

    QUEENSLAND UNIVERSITY OF TECHNOLOGY

    Responsibilities included preparing and delivering a guest lecture for the Department of Physical and Chemical Sciences in their unit, Cosmology (PVB220).
  • 2016
    2014

    SESSIONAL ACADEMIC

    MACQUARIE UNIVERSITY

    Responsibilities included preparing, delivering, and grading student performance in lectures and lab sessions for the Department of Physics and Astronomy in their units, Introductory Astronomy (ASTR170) and Advanced Astronomy (ASTR278).
  • 2013

    SESSIONAL ACADEMIC

    QUEENSLAND UNIVERSITY OF TECHNOLOGY

    Responsibilities included preparing, delivering, and grading student performance in lectures and lab sessions for the Department of Physical and Chemical Sciences in their units, Astrophysics 1 (PQB460), Astrophysics 2 (PQB660), Mechanical and Thermal Energy (ENB130), and Biomedical Physics (PCB150).
  • STUDENT SUPERVISION
  • 2017
    2016

    STUDENT: LACHLAN MARNOCH

    MACQUARIE UNIVERSITY

    Undergraduate Project: Characterising distant galaxies by way of spectral energy distribution analysis.
.04

PUBLICATIONS

PUBLICATIONS LIST
17 AUG 2018

ZFOURGE: USING COMPOSITE SPECTRAL ENERGY DISTRIBUTIONS TO CHARACTERIZE GALAXY
POPULATIONS AT 1 < z < 4

THE ASTROPHYSICAL JOURNAL, 863, 2 (2018)

We use composite SEDs to investigate the properties of galaxies as they shut off star formation over the 4 billion years surrounding peak cosmic star formation.

JOURNAL PAPER  Forrest, B., et al. [16 authors including, Cowley, M. J.]
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ZFOURGE: USING COMPOSITE SPECTRAL ENERGY DISTRIBUTIONS TO CHARACTERIZE GALAXY POPULATIONS AT 1 < z < 4

Forrest, B., et al. [16 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We investigate the properties of galaxies as they shut off star formation over the 4 billion years surrounding peak cosmic star formation. To do this, we categorize ∼7000 galaxies from 1 < z < 4 into 90 groups based on the shape of their spectral energy distributions (SEDs) and build composite SEDs with R ∼ 50 resolution. These composite SEDs show a variety of spectral shapes and also show trends in parameters such as color, mass, star formation rate, and emission-line equivalent width. Using emission-line equivalent widths and strength of the 4000 Å break, D(4000), we categorize the composite SEDs into five classes: extreme emission line, star-forming, transitioning, post-starburst, and quiescent galaxies. The transitioning population of galaxies shows modest Hα emission (EWREST ∼ 40 Å) compared to more typical star-forming composite SEDs at log(M*/M ∼ 10.5 (EWREST ∼ 80 Å). Together with their smaller sizes (3 kpc vs. 4 kpc) and higher Sérsic indices (2.7 vs. 1.5), this indicates that morphological changes initiate before the cessation of star formation. The transitional group shows a strong increase of over 1 dex in number density from z ∼ 3 to z ∼ 1, similar to the growth in the quiescent population, while post-starburst galaxies become rarer at z ≲ 1.5. We calculate average quenching timescales of 1.6 Gyr at z ∼ 1.5 and 0.9 Gyr at z ∼ 2.5 and conclude that a fast-quenching mechanism producing post-starbursts dominated the quenching of galaxies at early times, while a slower process has become more common since z ∼ 2.

3 MAY 2018

ZFIRE: 3D MODELING OF ROTATION, DISPERSION, AND ANGULAR MOMENTUM OF STAR-FORMING GALAXIES
AT z ∼ 2

THE ASTROPHYSICAL JOURNAL, 858, 47 (2018)

We perform a kinematic and morphological analysis of 44 star-forming galaxies at z ∼ 2 in the COSMOS legacy field using near-infrared spectroscopy from Keck/MOSFIRE and F160W imaging from CANDELS/3D-HST as part of the ZFIRE survey.

JOURNAL PAPER Alcorn, L. Y. et al. [13 authors including, Cowley, M. J.]
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ZFIRE: 3D MODELING OF ROTATION, DISPERSION, AND ANGULAR MOMENTUM OF STAR-FORMING GALAXIES AT z ∼ 2

Alcorn, L. Y. et al. [13 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We perform a kinematic and morphological analysis of 44 star-forming galaxies at z ∼ 2 in the COSMOS legacy field using near-infrared spectroscopy from Keck/MOSFIRE and F160W imaging from CANDELS/3D-HST as part of the ZFIRE survey. Our sample consists of cluster and field galaxies from 2.0 < z < 2.5 with K-band multi-object slit spectroscopic measurements of their Hα emission lines. Hα rotational velocities and gas velocity dispersions are measured using the Heidelberg Emission Line Algorithm (HELA), which compares directly to simulated 3D data cubes. Using a suite of simulated emission lines, we determine that HELA reliably recovers input S0.5 and angular momentum at small offsets, but V2.2g values are offset and highly scattered. We examine the role of regular and irregular morphology in the stellar mass kinematic scaling relations, deriving the kinematic measurement S0.5, and finding log(S0.5) = (0.38 ± 0.07)(log(M*/M - 10) + (20.04 ± 0.03) with no significant offset between morphological populations and similar levels of scatter (∼0.16 dex). Additionally, we identify a correlation between M* and V2.2g for the total sample, showing an increasing level of rotation dominance with increasing M*, and a high level of scatter for both regular and irregular galaxies. We estimate the specific angular momenta (jdisk) of these galaxies and find a slope of 0.36 ± 0.12, shallower than predicted without mass-dependent disk growth, but this result is possibly due to measurement uncertainty at M* < 9.5 However, through a Kolmogorov–Smirnov test we find irregular galaxies to have marginally higher jdisk values than regular galaxies, and high scatter at low masses in both populations.

17 APR 2018

THE EVOLUTIONARY IMPACT OF SUPERMASSIVE
BLACK HOLES ON THEIR HOST GALAXIES

MACQUARIE UNIVERSITY, MQ:70611

By exploiting the ultra-deep, Ks-band imaging of the FourStar Galaxy Evolution Survey (ZFOURGE), we investigate the evolutionary impact of supermassive black holes (SMBHs) on their host galaxies.

THESIS Cowley, M. J.
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THE EVOLUTIONARY IMPACT OF SUPERMASSIVE BLACK HOLES ON THEIR HOST GALAXIES

Cowley, M. J. THESIS Astrophysics

By exploiting the ultra-deep, Ks-band imaging of the FourStar Galaxy Evolution Survey (ZFOURGE), we investigate the evolutionary impact of supermassive black holes (SMBHs) on their host galaxies. We advance this line of research by applying new analyses to a more substantial number of sources, with higher quality photometric redshifts, over a broader redshift range, and down to deeper mass-limits than most studies before it. We begin by supplementing the ZFOURGE galaxy catalogues with data in radio, X-ray, and infrared wavebands to catalogue AGN host galaxies across a broad redshift range of z = 0.2 - 3.2. We then use these catalogues to construct a mass-complete, luminosity limited sample of AGN to compare their rest-frame U -- V versus V -- J (UVJ) colours and specific star formation rates (sSFRs) to a mass-matched control sample of inactive (non-AGN) galaxies. Our UVJ diagnostics reveal that the AGN tend to be hosted in a lower fraction of quiescent galaxies and a higher fraction of dusty galaxies than the control sample. Using 160 µm Herschel PACS data, we find the mean sSFRs of AGN hosts to be elevated by 0.34 ± 0.07 dex with respect to the control sample across all redshifts. This offset is primarily driven by infrared-selected AGN, where the mean sSFR is found to be elevated by as much as a factor of ∼5. The remaining population, comprised predominantly of X-ray AGN hosts, is found mostly consistent with inactive galaxies, exhibiting only a marginal elevation. To probe the elevated star formation (SF) found in our AGN samples, we turn our attention to infrared-selected AGN and apply techniques to separate the AGN and SF components of each galaxy’s spectral energy distribution (SED). We use this approach to estimate the black hole accretion rate (BHAR) and star formation rate (SFR) for Milky Way (MW) and Andromeda (M31-mass progenitors from z = 0.2 - 2.5. Our motivation here is to minimise the effects of AGN contamination and selection-bias as we track the evolution of the SF-AGN connection of these sources from high to low redshift. Specifically, we track the evolution of their quenching rate via UVJ diagnostics, and their relative black hole-galaxy growth (i.e. their BHAR/SFR ratio). We find as the progenitors evolve, their BHAR/SFR ratio does not track the rate at which progenitors quench. Furthermore, the logarithm of the BHAR/SFR ratio of MW-mass progenitors evolves with a slope of 0.64 - 0.11, whileM31-mass progenitors are 0.39 - 0.08. These results contrast with previous studies that find an almost flat slope when adopting X-ray/AGN-selected or mass-limited samples and is likely due to their use of a broad mixture of galaxies with different evolutionary histories. Our use of progenitor-matched samples highlights the potential importance of carefully selecting progenitors when searching for evolutionary relationships between SMBHs and their host galaxies. Finally, we present a new technique to isolate the AGN contribution to the observed SED using only two photometric bands. Such an approach lends itself to studies where abundant photometric data may be lacking. While our approach is not without its limitations, we show it can reproduce underlying trends known to exist in AGN samples. Specifically, we reproduce the SF-AGN correlation found in infrared-selected AGN. However, similar to the previous chapter, we highlight where selection-bias may be driving these results. Overall, this thesis adds significant evidence to the suggestion that correlations observed between SMBHs and their host galaxies may be driven by selection effects, while also casting doubts over the idea that the suppression of star formation is predominantly driven by the negative feedback of luminous AGN over most of cosmic time.

21 JAN 2018

DECOUPLED BLACK HOLE ACCRETION AND
QUENCHING: THE RELATIONSHIP BETWEEN BHAR,
SFR, AND QUENCHING IN MILKY WAY AND
ANDROMEDA-MASS PROGENITORS SINCE z = 2.5

THE MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 473, 3710-3716 (2017)

We investigate the relationship between the black hole accretion rate (BHAR) and star formation rate (SFR) for Milky Way (MW) and Andromeda (M31)-mass progenitors from z = 0.2 to 2.5.

JOURNAL PAPER Cowley, M. J., Spitler, L.R., Papovich, C., et al.
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DECOUPLED BLACK HOLE ACCRETION AND QUENCHING: THE RELATIONSHIP BETWEEN BHAR, SFR, AND QUENCHING IN MILKY WAY AND ANDROMEDA-MASS PROGENITORS SINCE z = 2.5

Cowley, M. J., Spitler, L.R., Papovich, C., et al. JOURNAL PAPER ASTROPHYSICS

We investigate the relationship between the black hole accretion rate (BHAR) and star formation rate (SFR) for Milky Way (MW) and Andromeda (M31)-mass progenitors from z = 0.2 to 2.5. We source galaxies from the Ks-band-selected ZFOURGE survey, which includes multiwavelength data spanning 0.3–160 µm. We use decomposition software to split the observed spectral energy distributions (SEDs) of our galaxies into their active galactic nuclei (AGNs) and star-forming components, which allows us to estimate BHARs and SFRs from the infrared (IR). We perform tests to check the robustness of these estimates, including a comparison with BHARs and SFRs derived from X-ray stacking and far-IR analysis, respectively. We find that, as the progenitors evolve their relative black hole–galaxy growth (i.e. their BHAR/SFR ratio) increases from low to high redshift. The MW-mass progenitors exhibit a log–log slope of 0.64 ± 0.11, while the M31-mass progenitors are 0.39 ± 0.08. This result contrasts with previous studies that find an almost flat slope when adopting X-ray-/AGN-selected or mass-limited samples and is likely due to their use of a broad mixture of galaxies with different evolutionary histories. Our use of progenitor-matched samples highlights the potential importance of carefully selecting progenitors when searching for evolutionary relationships between BHAR/SFRs. Additionally, our finding that BHAR/SFR ratios do not track the rate at which progenitors quench casts doubts over the idea that the suppression of star formation is predominantly driven by luminous AGN feedback (i.e. high BHARs).

24 OCT 2017

THE TAIPAN GALAXY SURVEY: SCIENTIFIC GOALS AND OBSERVING STRATEGY

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA, 34, 47 (2017)

The Taipan galaxy survey (hereafter simply 'Taipan') is a multi-object spectroscopic survey starting in 2017 that will cover 2π steradians over the southern sky (δ ≲ 10°, |b| ≳ 10°), and obtain optical spectra for about two million galaxies out to z < 0.4.

JOURNAL PAPER da Cunha, E., et al. [11 authors including, Cowley, M. J.]
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THE TAIPAN GALAXY SURVEY: SCIENTIFIC GOALS AND OBSERVING STRATEGY

da Cunha, E., et al. [11 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

The Taipan galaxy survey (hereafter simply 'Taipan') is a multi-object spectroscopic survey starting in 2017 that will cover 2π steradians over the southern sky (δ ≲ 10°, |b| ≳ 10°), and obtain optical spectra for about two million galaxies out to z < 0.4. Taipan will use the newly refurbished 1.2m UK Schmidt Telescope at Siding Spring Observatory with the new TAIPAN instrument, which includes an innovative 'Starbugs' positioning system capable of rapidly and simultaneously deploying up to 150 spectroscopic fibres (and up to 300 with a proposed upgrade) over the 6° diameter focal plane, and a purpose-built spectrograph operating in the range from 370 to 870 nm with resolving power R ≳ 2000. The main scientific goals of Taipan are (i) to measure the distance scale of the Universe (primarily governed by the local expansion rate, H0) to 1% precision, and the growth rate of structure to 5%; (ii) to make the most extensive map yet constructed of the total mass distribution and motions in the local Universe, using peculiar velocities based on improved Fundamental Plane distances, which will enable sensitive tests of gravitational physics; and (iii) to deliver a legacy sample of low-redshift galaxies as a unique laboratory for studying galaxy evolution as a function of dark matter halo and stellar mass and environment. The final survey, which will be completed within 5 yrs, will consist of a complete magnitude-limited sample (i ≤ 17) of about 1.2 × 106 galaxies supplemented by an extension to higher redshifts and fainter magnitudes (i ≤ 18.1) of a luminous red galaxy sample of about 0.8 × 106 galaxies. Observations and data processing will be carried out remotely and in a fully automated way, using a purpose-built automated 'virtual observer' software and an automated data reduction pipeline. The Taipan survey is deliberately designed to maximise its legacy value by complementing and enhancing current and planned surveys of the southern sky at wavelengths from the optical to the radio; it will become the primary redshift and optical spectroscopic reference catalogue for the local extragalactic Universe in the southern sky for the coming decade.

13 APR 2017

ZFIRE: THE EVOLUTION OF THE STELLAR MASS TULLY-FISHER RELATION TO REDSHIFT 2.0 < z < 2.5 WITH MOSFIRE

THE ASTROPHYSICAL JOURNAL, 839, 57 (2017)

Using observations made with MOSFIRE on Keck I as part of the ZFIRE survey, we present the stellar mass Tully–Fisher relation at 2.0 < z < 2.5.

JOURNAL PAPER Straatman, C. M. S., et al. [11 authors including, Cowley, M. J.]
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ZFIRE: THE EVOLUTION OF THE STELLAR MASS TULLY-FISHER RELATION TO REDSHIFT 2.0 < z < 2.5 WITH MOSFIRE

Straatman, C. M. S., et al. [11 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

Using observations made with MOSFIRE on Keck I as part of the ZFIRE survey, we present the stellar mass Tully–Fisher relation at 2.0 < z < 2.5. The sample was drawn from a stellar-mass-limited, Ks-band-selected catalog from ZFOURGE over the CANDELS area in the COSMOS field. We model the shear of the Hα emission line to derive rotational velocities at 2.2× the scale radius of an exponential disk (V2.2). We correct for the blurring effect of a 2D point-spread function (PSF) and the fact that the MOSFIRE PSF is better approximated by a Moffat than a Gaussian, which is more typically assumed for natural seeing. We find for the Tully–Fisher relation at 2.0 < z < 2.5 that log(V2.2) = (2.18 ± 0.051) + (0.193 ± 0.108)(log(M*/M - 10) and infer an evolution of the zero-point of ΔM/M = -0.25 ± 0.16 dex or ΔM/M = -0.39 ± 0.21 dex compared to z = 0 when adopting a fixed slope of 0.29 or 1/4.5, respectively. We also derive the alternative kinematic estimator S0.5, with a best-fit relation log(S0.5) = (2.06 ± 0.032) + (0.211 ± 0.086)(log(M*/M - 10), and infer an evolution of ΔM/M = -0.45 ± 0.13 dex compared to z < 1.2 if we adopt a fixed slope. We investigate and review various systematics, such as PSF effects, projection effects, systematics related to stellar mass derivation, selection biases, and slope. We find that discrepancies between the various literature values are reduced when taking these into account. Our observations correspond well with the gradual evolution predicted by semianalytic models.

24 MAR 2017

DISCOVERY OF EXTREME [OIII]+Hβ EMITTING GALAXIES TRACING AN OVERDENSITY AT z ∼ 3.5 IN CDF-SOUTH

THE ASTROPHYSICAL JOURNAL LETTERS, 838, L12 (2017)

We identify 60 galaxies that comprise a composite SED with a [O III] + Hβ rest-frame equivalent width of 803 ± 228 Å and another 218 galaxies in a composite SED with an equivalent width of 230 ± 90 Å. These EELGs are analogous to the "green peas" found in the SDSS

JOURNAL PAPER Forrest, B., et al., et al. [14 authors including, Cowley, M. J.]
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DISCOVERY OF EXTREME [OIII]+Hβ EMITTING GALAXIES TRACING AN OVERDENSITY AT z ∼ 3.5 IN CDF-SOUTH

Forrest, B., et al., et al. [14 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

Using deep multi-wavelength photometry of galaxies from zfourge, we group galaxies at 2.5 < z < 4.0 by the shape of their spectral energy distributions (SEDs). We identify a population of galaxies with excess emission in the Ks-band, which corresponds to [O III]+Hβ emission at 2.95 < z < 3.65. This population includes 78% of the bluest galaxies with UV slopes steeper than β = -2. We de-redshift and scale this photometry to build two composite SEDs, enabling us to measure equivalent widths of these extreme [O III] + Hβ emission line galaxies (EELGs) at z ∼ 3.5. We identify 60 galaxies that comprise a composite SED with a [O III] + Hβ rest-frame equivalent width of 803 ± 228 Å and another 218 galaxies in a composite SED with an equivalent width of 230 ± 90 Å. These EELGs are analogous to the "green peas" found in the SDSS and are thought to be undergoing their first burst of star formation due to their blue colors (β < -1.6), young ages (log(age yr-1) ∼ 7.2), and low dust attenuation values. Their strong nebular emission lines and compact sizes (typically ∼1.4 kpc) are consistent with the properties of the star-forming galaxies possibly responsible for re-ionizing the universe at z > 6. Many of the EELGs also exhibit Lyα emission. Additionally, we find that many of these sources are clustered in an over-density in the Chandra Deep Field South, with five spectroscopically confirmed members at z = 3.474 ± 0.004. The spatial distribution and photometric redshifts of the zfourge population further confirm the over-density highlighted by the EELGs.

14 MAR 2017

ZFIRE: USING Hα EQUIVALENT WIDTHS TO
INVESTIGATE THE IN SITU INITIAL MASS FUNCTION
AT z ∼ 2

THE MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 468, 3071-3108 (2017)

We use the ZFIRE survey to investigate the high-mass slope of the initial mass function (IMF) for a mass-complete (⁠log(M*/M ∼ 9.3) sample of 102 star-forming galaxies at z ∼ 2 using their Hα equivalent widths (Hα EWs) and rest-frame optical colours.

JOURNAL PAPER Nanayakkara, T., et al., et al. [12 authors including, Cowley, M. J.]
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ZFIRE: USING Hα EQUIVALENT WIDTHS TO INVESTIGATE THE IN SITU INITIAL MASS FUNCTION AT z ∼ 2

Nanayakkara, T., et al., et al. [12 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We use the ZFIRE survey to investigate the high-mass slope of the initial mass function (IMF) for a mass-complete (⁠log(M*/M ∼ 9.3) sample of 102 star-forming galaxies at z ∼ 2 using their Hα equivalent widths (Hα EWs) and rest-frame optical colours. We compare dust-corrected Hα EW distributions with predictions of star formation histories (SFHs) from PEGASE.2 and STARBURST99 synthetic stellar population models. We find an excess of high Hα EW galaxies that are up to 0.3–0.5 dex above the model-predicted Salpeter IMF locus and the Hα EW distribution is much broader (10–500 Å) than can easily be explained by a simple monotonic SFH with a standard Salpeter-slope IMF. Though this discrepancy is somewhat alleviated when it is assumed that there is no relative attenuation difference between stars and nebular lines, the result is robust against observational biases, and no single IMF (i.e. non-Salpeter slope) can reproduce the data. We show using both spectral stacking and Monte Carlo simulations that starbursts cannot explain the EW distribution. We investigate other physical mechanisms including models with variations in stellar rotation, binary star evolution, metallicity and the IMF upper-mass cut-off. IMF variations and/or highly rotating extreme metal-poor stars (Z ∼ 0.1 Z) with binary interactions are the most plausible explanations for our data. If the IMF varies, then the highest Hα EWs would require very shallow slopes (Γ > −1.0) with no one slope able to reproduce the data. Thus, the IMF would have to vary stochastically. We conclude that the stellar populations at z ≳ 2 show distinct differences from local populations and there is no simple physical model to explain the large variation in Hα EWs at z ∼ 2.

17 JAN 2017

MODELLING THE DYNAMICS OF A HYPOTHETICAL
PLANET X BY WAY OF GRAVITATIONAL N-BODY SIMULATOR

THE EUROPEAN JOURNAL OF PHYSICS, 38, 025602 (2017)

We present an activity, which allows students to debunk some of the myths surrounding Planet X by using simulation software to demonstrate that such a large-mass planet with extreme eccentricity would be unable to enter our Solar System unnoticed, let alone maintain a stable orbit.

JOURNAL PAPER Cowley, M. J., Hughes, S. W.
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MODELLING THE DYNAMICS OF A HYPOTHETICAL PLANET X BY WAY OF GRAVITATIONAL N-BODY SIMULATOR

Cowley, M. J., Hughes, S. W. JOURNAL PAPER EDUCATION

This paper describes a novel activity to model the dynamics of a Jupiter-mass, trans-Neptunian planet of a highly eccentric orbit. Despite a history rooted in modern astronomy, 'Planet X', a hypothesised hidden planet lurking in our outer Solar System, has often been touted by conspiracy theorists as the cause of past mass extinction events on Earth, as well as other modern-day doomsday scenarios. Frequently dismissed as pseudoscience by astronomers, these stories continue to draw the attention of the public by provoking mass media coverage. Targeted at junior undergraduate levels, this activity allows students to debunk some of the myths surrounding Planet X by using simulation software to demonstrate that such a large-mass planet with extreme eccentricity would be unable to enter our Solar System unnoticed, let alone maintain a stable orbit.

16 JAN 2017

TEACHING THE DOPPLER EFFECT IN ASTROPHYSICS

THE EUROPEAN JOURNAL OF PHYSICS, 38, 025603 (2017)

In this paper, a simple technique is described for teaching the basics of the Doppler effect to undergraduate astrophysics students using acoustic waves.

JOURNAL PAPER Hughes, S. W., Cowley, M. J.
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TEACHING THE DOPPLER EFFECT IN ASTROPHYSICS

Hughes, S. W., Cowley, M. J. JOURNAL PAPER EDUCATION

The Doppler effect is a shift in the frequency of waves emitted from an object moving relative to the observer. By observing and analysing the Doppler shift in electromagnetic waves from astronomical objects, astronomers gain greater insight into the structure and operation of our Universe. In this paper, a simple technique is described for teaching the basics of the Doppler effect to undergraduate astrophysics students using acoustic waves. An advantage of the technique is that it produces a visual representation of the acoustic Doppler shift. The equipment comprises a 40 kHz acoustic transmitter and a microphone. The sound is bounced off a computer fan and the signal collected by a DrDAQ ADC and processed by a spectrum analyser. Widening of the spectrum is observed as the fan power supply potential is increased from 4 to 12 V.

9 JAN 2017

THE SIZE EVOLUTION OF STAR-FORMING GALAXIES
SINCE z ∼ 7 USING ZFOURGE AND CANDELS

THE ASTROPHYSICAL JOURNAL LETTERS, 834, L11 (2016)

We present the size evolution of a mass-complete (log(M*/M) > 10) sample of star-forming galaxies over redshifts z = 1 – 7, selected from the FourStar Galaxy Evolution Survey.

JOURNAL PAPER Allen, R.J., et al. [13 authors including, Cowley, M. J.]
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THE SIZE EVOLUTION OF STAR-FORMING GALAXIES SINCE z ∼ 7 USING ZFOURGE AND CANDELS

Allen, R.J., et al. [13 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

For the first time, we present the size evolution of a mass-complete (log(M*/M) > 10) sample of star-forming galaxies over redshifts z = 1 – 7, selected from the FourStar Galaxy Evolution Survey. Observed H-band sizes are measured from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) Hubble Space Telescope (HST)/F160W imaging. Distributions of individual galaxy masses and sizes illustrate that a clear mass−size relation exists up to z ∼ 7. At z ∼ 7, we find that the average galaxy size from the mass−size relation is more compact at a fixed mass of log(M*/M) = 10.1, with r1/2,,aj = 1.02 ± 0.29 kpc, than at lower redshifts. This is consistent with our results from stacking the same CANDELS HST/F160W imaging, when we correct for galaxy position angle alignment. We find that the size evolution of star-forming galaxies is well fit by a power law of the form re = 7.07(1 + z)-0.89 kpc, which is consistent with previous works for normal star-formers at 1 < z < 4. In order to compare our slope with those derived Lyman break galaxy studies, we correct for different IMFs and methodology and find a slope of −0.97 ± 0.02, which is shallower than that reported for the evolution of Lyman break galaxies (LBGs) at z > 4 (re ∝ (1 + z)-1.2±0.06). Therefore, we conclude the LBGs likely represent a subset of highly star-forming galaxies that exhibit rapid size growth at z > 4.

5 JAN 2017

ZFIRE: SIMILAR STELLAR GROWTH IN Hα-EMITTING CLUSTER AND FIELD GALAXIES AT z ∼ 2

THE ASTROPHYSICAL JOURNAL, 834, 101 (2016)

We compare galaxy scaling relations as a function of environment at z ∼ 2 with our ZFIRE survey where we have measured Hα fluxes for 90 star-forming galaxies selected from a mass-limited (log(M*/M > 9) sample based on ZFOURGE.

JOURNAL PAPER Tran, K.-V., et al. [16 authors including, Cowley, M. J.]
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ZFIRE: SIMILAR STELLAR GROWTH IN Hα-EMITTING CLUSTER AND FIELD GALAXIES AT z ∼ 2

Tran, K.-V., et al. [16 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We compare galaxy scaling relations as a function of environment at z ∼ 2 with our ZFIRE survey where we have measured Hα fluxes for 90 star-forming galaxies selected from a mass-limited (log(M*/M > 9) sample based on ZFOURGE. The cluster galaxies (37) are part of a confirmed system at z = 2.095 and the field galaxies (53) are at 1.9 < z < 2.4 all are in the COSMOS legacy field. There is no statistical difference between Hα-emitting cluster and field populations when comparing their star formation rate (SFR), stellar mass (M*), galaxy size (reff), SFR surface density (∑(Hα*), and stellar age distributions. The only difference is that at fixed stellar mass, the Hα-emitting cluster galaxies are log(reff) ∼ 0.1 larger than in the field. Approximately 19% of the Hα emitters in the cluster and 26% in the field are IR-luminous (LIR > 2 × 1011 L). Because the luminous IR galaxies in our combined sample are ∼5 times more massive than the low-IR galaxies, their radii are ∼70% larger. To track stellar growth, we separate galaxies into those that lie above, on, or below the Hα star-forming main sequence (SFMS) using ΔSFR(M*) = ±0.2 dex. Galaxies above the SFMS (starbursts) tend to have higher Hα SFR surface densities and younger light-weighted stellar ages than galaxies below the SFMS. Our results indicate that starbursts (+SFMS) in the cluster and field at z ∼ 2 are growing their stellar cores. Lastly, we compare to the (SFR-M*) relation from Rhapsody-G cluster simulations and find that the predicted slope is nominally consistent with the observations. However, the predicted cluster SFRs tend to be too low by a factor of ∼2, which seems to be a common problem for simulations across environment.

01 JAN 2017

ZFIRE: SIMILAR STELLAR GROWTH IN Hα-EMITTING CLUSTER AND FIELD GALAXIES AT z ∼ 2

PROCEEDINGS OF THE AMERICAN ASTRONOMICAL SOCIETY, TEXAS, ID.229.02 (2017)

We compare galaxy scaling relations as a function of environment at z ∼ 2 with our ZFIRE survey where we have measured Halpha fluxes for 90 galaxies selected from a mass-limited sample based on ZFOURGE.

CONFERENCE Tran, K.-V., et al. [16 authors including, Cowley, M. J.]
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ZFIRE: SIMILAR STELLAR GROWTH IN Hα-EMITTING CLUSTER AND FIELD GALAXIES AT z ∼ 2

Tran, K.-V., et al. [16 authors including, Cowley, M. J.] CONFERENCE ASTROPHYSICS

We compare galaxy scaling relations as a function of environment at z ∼2 with our ZFIRE survey where we have measured Halpha fluxes for 90 galaxies selected from a mass-limited sample based on ZFOURGE. The cluster galaxies (37) are part of a spectroscopically confirmed system at z=2.095 and the field galaxies (53) have redshifts of 1.9 < z < 2.4. There is no statistical difference between Halpha-emitting cluster and field populations when comparing their star formation rate (SFR), stellar mass, galaxy size, star formation rate surface density, and stellar age distributions. Approximately 20-25% of Halpha-emitting galaxies in both the cluster and field are IR-luminous. In our combined cluster and field sample, IR-luminous galaxies have ∼5 times more stellar mass and radii that are ∼70% larger than the low-IR galaxies. To track stellar growth, we separate galaxies into those that lie above, on, and below the Halpha star-forming main sequence (SFMS) using delta[SFR]=+/-0.2 dex. Galaxies above the SFMS (starbursts) tend to have higher Halpha SFR surface densities and younger stellar ages compared to galaxies below the SFMS. Our results indicate that starbursts (+SFMS) in the cluster and field at z ∼ 2 are growing their stellar cores. Lastly, we compare to the (SFR-stellar mass) relation predicted by the RHAPSODY galaxy cluster simulations and find that the predicted slope is nominally consistent with the observations. However, the predicted cluster SFRs tend to be too low by a factor of ∼2 which suggests that simulations may be over-predicting how efficient environment is at quenching star formation.

10 OCT 2016

THE FOURSTAR GALAXY EVOLUTION SURVEY
(ZFOURGE): UV TO FAR-IR CATALOGS, MEDIUM-BANDWIDTH PHOTOMETRIC REDSHIFTS WITH
IMPROVED ACCURACY, STELLAR MASSES, AND CONFIRMATION OF QUIESCENT GALAXIES TO z ∼ 3.5

THE ASTROPHYSICAL JOURNAL, 830, 51 (2016)

We present photometric catalogs comprising >70,000 galaxies, selected from ultradeep Ks-band detection images (25.5 – 26.5 AB mag, 5σ, total), and >80% complete to K2 < 25.3 – 25.9 AB.

JOURNAL PAPER Straatman, C. M. S., et al. [29 authors including, Cowley, M. J.]
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THE FOURSTAR GALAXY EVOLUTION SURVEY (ZFOURGE): UV TO FAR-IR CATALOGS, MEDIUM-BANDWIDTH PHOTOMETRIC REDSHIFTS WITH IMPROVED ACCURACY, STELLAR MASSES, AND CONFIRMATION OF QUIESCENT GALAXIES TO z ∼ 3.5

Straatman, C. M. S., et al. [29 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

The FourStar galaxy evolution survey (ZFOURGE) is a 45 night legacy program with the FourStar near-infrared camera on Magellan and one of the most sensitive surveys to date. ZFOURGE covers a total of 400 arcmin2 in cosmic fields CDFS, COSMOS and UDS, overlapping CANDELS. We present photometric catalogs comprising >70,000 galaxies, selected from ultradeep Ks-band detection images (25.5 – 26.5 AB mag, 5σ, total), and >80% complete to K2 < 25.3 – 25.9 AB. We use 5 near-IR medium-bandwidth filters (J1, J2, J3, H2, Hl) as well as broad-band K2 at 1.05 – 2.16 µm to 25 – 26 AB at a seeing of ∼0."5. Each field has ancillary imaging in 26 – 40 filters at 0.3 – 8 µm. We derive photometric redshifts and stellar population properties. Comparing with spectroscopic redshifts indicates a photometric redshift uncertainty σz = 0.010, 0.009, and 0.011 in CDFS, COSMOS, and UDS. As spectroscopic samples are often biased toward bright and blue sources, we also inspect the photometric redshift differences between close pairs of galaxies, finding σz,pairs = 0.01 – 0.02 at 1 < z < 2.5. We quantify how σz,pairs depends on redshift, magnitude, spectral energy distribution type, and the inclusion of FourStar medium bands. σz,pairs is smallest for bright, blue star-forming samples, while red star-forming galaxies have the worst σz,pairs. Including FourStar medium bands reduces σz,pairs by 50% at 1.5 < z < 2.5. We calculate star formation rates (SFRs) based on ultraviolet and ultradeep far-IR Spitzer/MIPS and Herschel/PACS data. We derive rest-frame U−V and V−J colors, and illustrate how these correlate with specific SFR and dust emission to z = 3.5. We confirm the existence of quiescent galaxies at z ∼ 3, demonstrating their SFRs are suppressed by > ×15.

24 AUG 2016

ZFIRE: A KECK/MOSFIRE SPECTROSCOPIC SURVEY OF GALAXIES IN RICH ENVIRONMENTS AT z ∼ 2

THE ASTROPHYSICAL JOURNAL, 828, 21 (2016)

We present an overview and the first data release of ZFIRE, a spectroscopic redshift survey of star-forming galaxies that utilizes the MOSFIRE instrument on Keck-I to study galaxy properties in rich environments at 1.5 < z < 2.5.

JOURNAL PAPER Nanayakkara, T., et al. [14 authors including, Cowley, M. J.]
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ZFIRE: A KECK/MOSFIRE SPECTROSCOPIC SURVEY OF GALAXIES IN RICH ENVIRONMENTS AT z ∼ 2

Nanayakkara, T., et al. [14 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We present an overview and the first data release of ZFIRE, a spectroscopic redshift survey of star-forming galaxies that utilizes the MOSFIRE instrument on Keck-I to study galaxy properties in rich environments at 1.5 < z < 2.5. ZFIRE measures accurate spectroscopic redshifts and basic galaxy properties derived from multiple emission lines. The galaxies are selected from a stellar mass limited sample based on deep near infrared imaging (KAB < 25) and precise photometric redshifts from the ZFOURGE and UKIDSS surveys as well as grism redshifts from 3DHST. Between 2013 and 2015, ZFIRE has observed the COSMOS and UDS legacy fields over 13 nights and has obtained 211 galaxy redshifts over 1.57 < z < 2.66 from a combination of nebular emission lines (such as Hα, [N II], Hβ, [O II], [O III], and [S II]) observed at 1–2 µm. Based on our medium-band near infrared photometry, we are able to spectrophotometrically flux calibrate our spectra to ∼10% accuracy. ZFIRE reaches 5σ emission line flux limits of ∼3 × 10 − 18 erg s-1 cm-2 with a resolving power of R = 3500 and reaches masses down to ∼109 M. We confirm that the primary input survey, ZFOURGE, has produced photometric redshifts for star-forming galaxies (including highly attenuated ones) accurate to Δz/(1 + zspec) = 0.015 with 0.7% outliers. We measure a slight redshift bias of <0.001, and we note that the redshift bias tends to be larger at higher masses. We also examine the role of redshift on the derivation of rest-frame colors and stellar population parameters from SED fitting techniques. The ZFIRE survey extends spectroscopically confirmed z ∼ 2 samples across a richer range of environments, here we make available the first public release of the data for use by the community.

01 AUG 2016

AN ENHANCEMENT OF 160 µM-DERIVED STAR-FORMATION RATES IN ACTIVE GALAXIES TO z = 3.2
WITH THE ZFOURGE SURVEY

PROCEEDINGS OF THE ESO CONFERENCE, ESO, GARCHING, ID. 85. (2016)

By supplementing the high-quality ZFOURGE galaxy catalogues with data in radio, X- ray, and infrared wavebands, we have studied the complex interplay between AGNs and their host galaxies to a time when the Universe was only 10-15% of its present age.

CONFERENCE Cowley, M. J., Spitler, L. R.
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AN ENHANCEMENT OF 160 µM-DERIVED STAR-FORMATION RATES IN ACTIVE GALAXIES TO z = 3.2
WITH THE ZFOURGE SURVEY

Cowley, M. J., Spitler, L. R. CONFERENCE ASTROPHYSICS

ZFOURGE is a new imaging survey, which employs unique near-infrared medium- band filters designed to probe galaxy properties over the last 12 billion years. By supplementing the high-quality ZFOURGE galaxy catalogues with data in radio, X- ray, and infrared wavebands, we have studied the complex interplay between AGNs and their host galaxies to a time when the Universe was only 10-15% of its present age. I will report on our study to compare the 160-um derived star-formation rates in active and non-active galaxies and show that AGN hosts, over all redshifts, tend to exhibit an elevated average star-formation activity compared to their non-active counterparts.

27 JUL 2016

LARGE SCALE STRUCTURE AROUND A z = 2.1 CLUSTER

THE ASTROPHYSICAL JOURNAL, 826, 130 (2016)

We present a search of large-scale structure around a galaxy cluster core at z = 2.095 using a set of spectroscopically confirmed galaxies.

JOURNAL PAPER Hung, C-L., et al. [13 authors including, Cowley, M. J.]
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LARGE SCALE STRUCTURE AROUND A z = 2.1 CLUSTER

Hung, C-L., et al. [13 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

The most prodigious starburst galaxies are absent in massive galaxy clusters today, but their connection with large-scale environments is less clear at z ≳ 2. We present a search of large-scale structure around a galaxy cluster core at z = 2.095 using a set of spectroscopically confirmed galaxies. We find that both color-selected star-forming galaxies (SFGs) and dusty star-forming galaxies (DSFGs) show significant overdensities around the z = 2.095 cluster. A total of eight DSFGs (including three X-ray luminous active galactic nuclei, AGNs) and 34 SFGs are found within a 10' radius (corresponds to ∼15 cMpc at z ∼ 2.1) from the cluster center and within a redshift range of Δz = 0.02, which leads to galaxy overdensities of δDSFG ∼ 12.3 and δSFG ∼ 2.8. The cluster core and the extended DSFG- and SFG-rich structures together demonstrate an active cluster formation phase, in which the cluster is accreting a significant amount of material from large-scale structure while the more mature core may begin to virialize. Our finding of this DSFG-rich structure, along with a number of other protoclusters with excess DSFGs and AGNs found to date, suggest that the overdensities of these rare sources indeed trace significant mass overdensities. However, it remains puzzling how these intense star formers are triggered concurrently. Although an increased probability of galaxy interactions and/or enhanced gas supply can trigger the excess of DSFGs, our stacking analysis based on 850 µm images and morphological analysis based on rest-frame optical imaging do not show such enhancements of merger fraction and gas content in this structure.

21 JUL 2016

DIFFERENCES IN THE STRUCTURAL PROPERTIES AND STAR-FORMATION RATES OF FIELD AND CLUSTER GALAXIES AT z ∼ 1

THE ASTROPHYSICAL JOURNAL, 826, 60 (2016)

We investigate the dependence of galaxy sizes and star formation rates (SFRs) on their environment using a mass-limited sample of quiescent and star-forming galaxies with log(M*/M) ≥ 9.5 at z̄ = 0.92 selected from the NEWFIRM medium-band Survey (NMBS).

JOURNAL PAPER Allen, R.J., et al. [8 authors including, Cowley, M. J.]
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DIFFERENCES IN THE STRUCTURAL PROPERTIES AND STAR-FORMATION RATES OF FIELD AND CLUSTER GALAXIES AT z ∼ 1

Allen, R.J., et al. [8 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We investigate the dependence of galaxy sizes and star formation rates (SFRs) on their environment using a mass-limited sample of quiescent and star-forming galaxies with log(M*/M) ≥ 9.5 at z̄ = 0.92 selected from the NEWFIRM medium-band Survey (NMBS). Using the Galaxy Environment Evolution Collaboration 2 spectroscopic cluster catalog and the accurate photometric redshifts from the NMBS, we select quiescent and star-forming cluster (σ̄ = 490 km s-1) galaxies within two virial radius, Rvir, intervals of 2 > Rvir > 0.5 and Rvir ≤ 0.5. Galaxies residing outside of the 2 Rvir of both the cluster centers and the additional candidate over-densities are defined as our field sample. Galaxy structural parameters are measured from the COSMOS legacy Hubble Space Telescope/ACS F814W image. The sizes and Sersic indices of quiescent field and cluster galaxies have the same distribution regardless of Rvir. However, cluster star-forming galaxies within 0.5 Rvir have lower mass-normalized average sizes by 16 ± 7%, and a higher fraction of Sersic indices with n > 1, than field star-forming galaxies. The average SFRs of star-forming cluster galaxies show a trend of decreasing SFR with clustocentric radius. The mass-normalized average SFR of cluster star-forming galaxies is a factor of 2 - 2.5 (7 - 9 σ) lower than that of star-forming galaxies in the field. While we find no significant dependence on environment for quiescent galaxies, the properties of star-forming galaxies are affected, which could be the result of environment acting on their gas content.

19 JUL 2016

COLD-MODE ACCRETION: DRIVING THE
FUNDAMENTAL MASS-METALLICITY RELATION AT z ∼ 2

THE ASTROPHYSICAL JOURNAL LETTERS, 826, L11 (2016)

We investigate the star formation rate (SFR) dependence on the stellar mass and gas-phase metallicity relation at z = 2 with MOSFIRE/Keck as part of the ZFIRE survey.

JOURNAL PAPER Kacprzak, G. G., et al. [14 authors including, Cowley, M. J.]
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COLD-MODE ACCRETION: DRIVING THE FUNDAMENTAL MASS-METALLICITY RELATION AT z ∼ 2

Kacprzak, G. G., et al. [14 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We investigate the star formation rate (SFR) dependence on the stellar mass and gas-phase metallicity relation at z = 2 with MOSFIRE/Keck as part of the ZFIRE survey. We have identified 117 galaxies (1.98 ≤ z ≤ 2.56), with 8.9 ≤ log(M*)/M) ≤ 11.0, for which we can measure gas-phase metallicities. For the first time, we show a discernible difference between the mass–metallicity relation, using individual galaxies, when dividing the sample by low (< 10 Myr-1) and high (> 10 Myr-1) SFRs. At fixed mass, low star-forming galaxies tend to have higher metallicity than high star-forming galaxies. Using a few basic assumptions, we further show that the gas masses and metallicities required to produce the fundamental mass–metallicity relation and its intrinsic scatter are consistent with cold-mode accretion predictions obtained from the OWLS hydrodynamical simulations. Our results from both simulations and observations are suggestive that cold-mode accretion is responsible for the fundamental mass–metallicity relation at z = 2 and it demonstrates the direct relationship between cosmological accretion and the fundamental properties of galaxies.

23 JUN 2016

ZFIRE: THE KINEMATICS OF STAR-FORMING GALAXIES
AS A FUNCTION OF ENVIRONMENT AT z ∼ 2

THE ASTROPHYSICAL JOURNAL LETTERS, 825, L2 (2016)

We perform a kinematic analysis of galaxies at z ∼ 2 in the COSMOS legacy field using near-infrared (NIR) spectroscopy from Keck/MOSFIRE as part of the ZFIRE survey.

JOURNAL PAPER Alcorn, L. Y. et al. [15 authors including, Cowley, M. J.]
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ZFIRE: THE KINEMATICS OF STAR-FORMING GALAXIES AS A FUNCTION OF ENVIRONMENT AT z ∼ 2

Alcorn, L. Y. et al. [15 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We perform a kinematic analysis of galaxies at z ∼ 2 in the COSMOS legacy field using near-infrared (NIR) spectroscopy from Keck/MOSFIRE as part of the ZFIRE survey. Our sample consists of 75 Ks-band selected star-forming galaxies from the ZFOURGE survey with stellar masses ranging from log(M*)/M) = 9.0 – 11.0, 28 of which are members of a known overdensity at z = 2.095. We measure Hα emission-line integrated velocity dispersions (σint) from 50 to 230 km s-1, consistent with other emission-line studies of z ∼ 2 field galaxies. From these data we estimate virial, stellar, and gas masses and derive correlations between these properties for cluster and field galaxies at z ∼ 2. We find evidence that baryons dominate within the central effective radius. However, we find no statistically significant differences between the cluster and the field, and conclude that the kinematics of star-forming galaxies at z ∼ 2 are not significantly different between the cluster and field environments.

03 MAR 2016

ZFIRE: ISM PROPERTIES OF THE z = 2.095 COSMOS CLUSTER

THE ASTROPHYSICAL JOURNAL, 819, 100 (2016)

We investigate the ISM properties of 13 star-forming galaxies within the z ∼ 2 COSMOS cluster.

JOURNAL PAPER Kewley, L. J., et al. [11 authors including, Cowley, M. J.]
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ZFIRE: ISM PROPERTIES OF THE z = 2.095 COSMOS CLUSTER

Kewley, L. J., et al. [11 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We investigate the ISM properties of 13 star-forming galaxies within the z ∼ 2 COSMOS cluster. We show that the cluster members have [NII]/Hα and [OIII]/Hβ emission-line ratios similar to z ∼ 2 field galaxies, yet systematically different emission-line ratios (by ∼0.17 dex) from the majority of local star-forming galaxies. We find no statistically significant difference in the [NII]/Hα and [OIII]/Hβ line ratios or ISM pressures among the z ∼ 2 cluster galaxies and field galaxies at the same redshift. We show that our cluster galaxies have significantly larger ionization parameters (by up to an order of magnitude) than local star-forming galaxies. We hypothesize that these high ionization parameters may be associated with large specific star formation rates (SFRs; i.e., a large SFR per unit stellar mass). If this hypothesis is correct, then this relationship would have important implications for the geometry and/or the mass of stars contained within individual star clusters as a function of redshift.

02 FEB 2016

UV TO IR LUMINOSITIES AND DUST ATTENUATION DETERMINED FROM ∼4000 K-SELECTED GALAXIES
AT 1 ≤ z < 3 IN THE ZFOURGE SURVEY

THE ASTROPHYSICAL JOURNAL LETTERS, 818, L26 (2016)

We build a set of composite galaxy spectral energy distributions (SEDs) to analyze the rest-frame UVJ colors, as well as the ratio of IR to UV light (IRX) and the UV slope (β) in the IRX−β dust relation at 1 < z < 3.

JOURNAL PAPER Forrest, B., et al. [25 authors including, Cowley, M. J.]
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THE SFR−M* RELATION AND EMPIRICAL STAR FORMATION HISTORIES FROM ZFOURGE AT 0.5 < z < 4

Forrest, B., et al. [25 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We build a set of composite galaxy spectral energy distributions (SEDs) by de-redshifting and scaling multi-wavelength photometry from galaxies in the ZFOURGE survey, covering the CDFS, COSMOS, and UDS fields. From a sample of ∼4000 Ks-band selected galaxies, we define 38 composite galaxy SEDs that yield continuous low-resolution spectra (R ∼ 45) over the rest-frame range 0.1–4 µm. Additionally, we include far infrared photometry from the Spitzer Space Telescope and the Herschel Space Observatory to characterize the infrared properties of our diverse set of composite SEDs. From these composite SEDs we analyze the rest-frame UVJ colors, as well as the ratio of IR to UV light (IRX) and the UV slope (β) in the IRX−β dust relation at 1 < z < 3. Blue star-forming composite SEDs show IRX and β values consistent with local relations; dusty star-forming galaxies have considerable scatter, as found for local IR bright sources, but on average appear bluer than expected for their IR fluxes. We measure a tight linear relation between rest-frame UVJ colors and dust attenuation for star-forming composites, providing a direct method for estimating dust content from either U − V or V - J rest-frame colors for star-forming galaxies at intermediate redshifts.

27 JAN 2016

THE SFR−M* RELATION AND EMPIRICAL STAR
FORMATION HISTORIES FROM ZFOURGE AT 0.5 < z < 4

THE ASTROPHYSICAL JOURNAL, 817, 118 (2015)

Using data from the FourStar Galaxy Evolution Survey (ZFOURGE) in combination with far-IR imaging from the Spitzer and Herschel observatories we measure the SFR–M* relation at 0.5 < z < 4.

JOURNAL PAPER Tomczak, A. R., et al. [21 authors including, Cowley, M. J.]
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THE SFR−M* RELATION AND EMPIRICAL STAR FORMATION HISTORIES FROM ZFOURGE AT 0.5 < z < 4

Tomczak, A. R., et al. [21 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We explore star formation histories (SFHs) of galaxies based on the evolution of the star formation rate stellar mass relation (SFR–M*). Using data from the FourStar Galaxy Evolution Survey (ZFOURGE) in combination with far-IR imaging from the Spitzer and Herschel observatories we measure the SFR–M* relation at 0.5 < z < 4. Similar to recent works we find that the average infrared spectral energy distributions of galaxies are roughly consistent with a single infrared template across a broad range of redshifts and stellar masses, with evidence for only weak deviations. We find that the SFR–M* relation is not consistent with a single power law of the form SFR ∝ M*α at any redshift; it has a power law slope of α ∼ 1 at low masses, and becomes shallower above a turnover mass (M0) that ranges from 109.5 to 1010.8 M, with evidence that M0 increases with redshift. We compare our measurements to results from state-of-the-art cosmological simulations, and find general agreement in the slope of the SFR–M* relation albeit with systematic offsets. We use the evolving SFR–M* sequence to generate SFHs, finding that typical SFRs of individual galaxies rise at early times and decline after reaching a peak. This peak occurs earlier for more massive galaxies. We integrate these SFHs to generate mass growth histories and compare to the implied mass growth from the evolution of the stellar mass function (SMF). We find that these two estimates are in broad qualitative agreement, but that there is room for improvement at a more detailed level. At early times the SFHs suggest mass growth rates that are as much as 10 times higher than inferred from the SMF. However, at later times the SFHs under-predict the inferred evolution, as is expected in the case of additional growth due to mergers.

22 JAN 2016

ZFOURGE CATALOGUE OF AGN CANDIDATES: AN ENHANCEMENT OF 160µM-DERIVED STAR
FORMATION RATES IN ACTIVE GALAXIES TO z = 3.2

THE MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 457, 629–641 (2015)

We investigate active galactic nuclei (AGN) candidates within the FourStar Galaxy Evolution Survey (ZFOURGE) to determine the impact they have on star formation in their host galaxies.

JOURNAL PAPER Cowley, M. J., Spitler, L.R., Tran, K.-V., et al.
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ZFOURGE CATALOGUE OF AGN CANDIDATES: AN ENHANCEMENT OF 160µM-DERIVED STAR FORMATION RATES IN ACTIVE GALAXIES TO z = 3.2

Cowley, M. J., Spitler, L.R., Tran, K.-V., et al. JOURNAL PAPER ASTROPHYSICS

We investigate active galactic nuclei (AGN) candidates within the FourStar Galaxy Evolution Survey (ZFOURGE) to determine the impact they have on star formation in their host galaxies. We first identify a population of radio, X-ray, and infrared-selected AGN by cross-matching the deep Ks-band imaging of ZFOURGE with overlapping multiwavelength data. From this, we construct a mass-complete (log(M*/M) ≥ 9.5), AGN luminosity limited sample of 235 AGN hosts over z = 0.2 – 3.2. We compare the rest-frame U − V versus V − J (UVJ) colours and specific star formation rates (sSFRs) of the AGN hosts to a mass-matched control sample of inactive (non-AGN) galaxies. UVJ diagnostics reveal AGN tend to be hosted in a lower fraction of quiescent galaxies and a higher fraction of dusty galaxies than the control sample. Using 160 µm Herschel PACS data, we find the mean specific star formation rate of AGN hosts to be elevated by 0.34 ± 0.07 dex with respect to the control sample across all redshifts. This offset is primarily driven by infrared-selected AGN, where the mean sSFR is found to be elevated by as much as a factor of ∼5. The remaining population, comprised predominantly of X-ray AGN hosts, is found mostly consistent with inactive galaxies, exhibiting only a marginal elevation. We discuss scenarios that may explain these findings and postulate that AGN are less likely to be a dominant mechanism for moderating galaxy growth via quenching than has previously been suggested.

19 JAN 2016

SATELLITE QUENCHING AND GALACTIC CONFORMITY
AT 0.3 < z < 2.5

THE ASTROPHYSICAL JOURNAL, 817, 9 (2015)

We measure the evolution of the quiescent fraction and quenching efficiency of satellites around star-forming and quiescent central galaxies with stellar mass log(Mcen/M) > 10.5 at 0.3 < z < 2.5.

JOURNAL PAPER Kawinwanichakij, L., et al. [24 authors including, Cowley, M. J.]
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THE SFR−M* RELATION AND EMPIRICAL STAR FORMATION HISTORIES FROM ZFOURGE AT 0.5 < z < 4

Kawinwanichakij, L., et al. [24 authors including, Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We measure the evolution of the quiescent fraction and quenching efficiency of satellites around star-forming and quiescent central galaxies with stellar mass log(Mcen/M) > 10.5 at 0.3 < z < 2.5. We combine imaging from three deep near-infrared-selected surveys (ZFOURGE/CANDELS, Ultra Deep Survey, and UltraVISTA), which allows us to select a stellar-mass complete sample of satellites with log(Msat/M) > 9.3. Satellites for both star-forming and quiescent central galaxies ("centrals") have higher quiescent fractions compared to field galaxies matched in stellar mass at all redshifts. We also observe "galactic conformity": satellites around quiescent centrals are more likely to be quenched compared to the satellites around star-forming centrals. In our sample, this conformity signal is significant at ≳ 3σ for 0.6 < z < 1.6, whereas it is only weakly significant at 0.3 < z < 0.6 and 1.6 < z < 2.5. Therefore, conformity (and thus satellite quenching) has been present for a significant fraction of the age of the universe. The satellite quenching efficiency increases with increasing stellar mass of the central, but does not appear to depend on the stellar mass of the satellite to the mass limit of our sample. When we compare the satellite quenching efficiency of star-forming centrals with stellar masses 0.2 dex higher than quiescent centrals (which should account for any difference in halo mass), the conformity signal decreases, but remains statistically significant at 0.6 < z < 0.9. This is evidence that satellite quenching is connected to the star formation properties of the central galaxy as well as to the mass of the halo. We discuss physical effects that may contribute to galactic conformity, and emphasize that they must allow for continued star formation in the central galaxy even as the satellites are quenched.

25 NOV 2015

RADIO GALAXIES IN ZFOURGE/NMBS: NO DIFFERENCE BETWEEN RADIO-AGN AND NON-RADIO-AGN HOSTS
TO z = 2.25

THE MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 455, 2731–2744 (2015)

Using the ZFOURGE (FourStar Galaxy Evolution) and NMBS (Newfirm Medium Band Survey) galaxy surveys, we investigate the host galaxy properties of a mass-limited (M ≥ 10.5M), high-luminosity (L1.4 > 1024 W Hz-1) sample of radio-loud AGN to a redshift of z = 2.25.

JOURNAL PAPER Rees, G. A., Spitler, L.R., Norris, R.P., Cowley, M. J., et al.
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RADIO GALAXIES IN ZFOURGE/NMBS: NO DIFFERENCE BETWEEN RADIO-AGN AND NON-RADIO-AGN HOSTS TO z = 2.25

Rees, G. A., Spitler, L.R., Norris, R.P., Cowley, M. J., et al. JOURNAL PAPER ASTROPHYSICS

In order to reproduce the high-mass end of the galaxy mass distribution, some process must be responsible for the suppression of star formation in the most massive of galaxies. Commonly active galactic nuclei (AGN) are invoked to fulfil this role, but the exact means by which they do so is still the topic of much debate, with studies finding evidence for both the suppression and enhancement of star formation in AGN hosts. Using the ZFOURGE (FourStar Galaxy Evolution) and NMBS (Newfirm Medium Band Survey) galaxy surveys, we investigate the host galaxy properties of a mass-limited (M ≥ 10.5M), high-luminosity (L1.4 > 1024 W Hz-1) sample of radio-loud AGN to a redshift of z = 2.25. In contrast to low-redshift studies, which associate radio-AGN activity with quiescent hosts, we find that the majority of z > 1.5 radio-AGN are hosted by star-forming galaxies. Indeed, the stellar populations of radio-AGN are found to evolve with redshift in a manner that is consistent with the non-AGN mass-similar galaxy population. Interestingly, we find that the radio-AGN fraction is constant across a redshift range of 0.25 ≤ z < 2.25, perhaps indicating that the radio-AGN duty cycle has little dependence on redshift or galaxy type. We do however see a strong relation between the radio-AGN fraction and stellar mass, with radio-AGN becoming rare below ∼1010.5 M or a halo mass of 1012 M. This halo-mass threshold is in good agreement with simulations that initiate radio-AGN feedback at this mass limit. Despite this, we find that radio-AGN host star formation rates are consistent with the non-AGN mass-similar galaxy sample, suggesting that while radio-AGN are in the right place to suppress star formation in massive galaxies they are not necessarily responsible for doing so.

10 NOV 2015

THE ATMOSPHERIC EXTINCTION OF LIGHT

THE EUROPEAN JOURNAL OF PHYSICS, 37, 015601 (2015)

An experiment is described that enables students to understand the properties of atmospheric extinction due to Rayleigh scattering. The experiment requires the use of red, green and blue lasers attached to a traveling microscope or similar device.

JOURNAL PAPER Hughes, S. W., Cowley, M. J., Powell, S., Carroll, J.
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THE ATMOSPHERIC EXTINCTION OF LIGHT

Hughes, S. W., Cowley, M. J., Powell, S., Carroll, J. JOURNAL PAPER EDUCATION

An experiment is described that enables students to understand the properties of atmospheric extinction due to Rayleigh scattering. The experiment requires the use of red, green and blue lasers attached to a traveling microscope or similar device. The laser beams are passed through an artificial atmosphere, made from milky water, at varying depths, before impinging on either a light meter or a photo diode integral to a Picotech Dr. DAQ ADC. A plot of measured spectral intensity verses depth reveals the contribution Rayleigh scattering has to the extinction coefficient. For the experiment with the light meter, the extinction coefficients for red, green and blue light in the milky sample of water were 0.27, 0.36 and 0.47 cm-1 respectively and 0.032, 0.037 and 0.092 cm-1 for the Picotech Dr. DAQ ADC.

10 SEP 2015

PARALLAX IN THE PARK

THE EUROPEAN JOURNAL OF PHYSICS, 36, 065030 (2015)

This article describes a parallax experiment performed by undergraduate physics students at Queensland University of Technology. The experiment is analogous to the parallax method used in astronomy to measure distances to the local stars.

JOURNAL PAPER Hughes, S. W., Powell, S., Carroll, J., Cowley, M. J.
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PARALLAX IN THE PARK

Hughes, S. W., Powell, S., Carroll, J., Cowley, M. J. JOURNAL PAPER EDUCATION

This article describes a parallax experiment performed by undergraduate physics students at Queensland University of Technology. The experiment is analogous to the parallax method used in astronomy to measure distances to the local stars. The result of one of these experiments is presented in this paper. A target was photographed using a digital camera at five distances between 3 and 8 metres from two vantage points spaced 0.6 m apart. The parallax distances were compared with the actual distance measured using a tape measure and the average error was 0.5 +/- 0.9%.

23 JUL 2015

THE SIZES OF MASSIVE QUIESCENT AND STAR
FORMING GALAXIES AT z ∼ 4 WITH ZFOURGE AND CANDELS

THE ASTROPHYSICAL JOURNAL LETTERS, 808, L29 (2015)

We study the rest-frame ultraviolet (UV) sizes of massive (∼0.8 × 1011 M) galaxies at 3.4 ≤ z < 4.2, selected from the FourStar Galaxy Evolution Survey.

JOURNAL PAPER Straatman, C. M. S., et al. [20 authors, including Cowley, M. J.]
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THE SIZES OF MASSIVE QUIESCENT AND STAR FORMING GALAXIES AT z ∼ 4 WITH ZFOURGE AND CANDELS

Straatman, C. M. S., et al. [20 authors, including Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We study the rest-frame ultraviolet (UV) sizes of massive (∼0.8 × 1011 M) galaxies at 3.4 ≤ z < 4.2, selected from the FourStar Galaxy Evolution Survey, by fitting single Sérsic profiles to Hubble Space Telescope/WFC3/F160W images from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. Massive quiescent galaxies are very compact, with a median circularized half-light radius re = 0.63 +/- 0.18 kpc. Removing 5/16 (31%) sources with signs of active galactic nucleus activity does not change the result. Star-forming galaxies have re = 2.0 +/- 0.60 kpc, 3.2+/- 1.3 × larger than quiescent galaxies. Quiescent galaxies at z ∼ 4 are on average 6.0 +/- 1.7 × smaller than at z ∼ 0 and 1.9 +/- 0.7 × smaller than at z ∼ 2. Star-forming galaxies of the same stellar mass are 2.4 +/- 0.7 × smaller than at z ∼ 0. Overall, the size evolution at 0 < z < 4 is well described by a power law, with re = 5.08 +/- 0.28(1+z)-1.44 +/- 0.08 kpc for quiescent galaxies and re = 6.02 +/- 0.28(1+z)-0.72 +/- 0.05 kpc for star-forming galaxies. Compact star-forming galaxies are rare in our sample: we find only 1/14 (7%) with re /{(M /1011 M)0.75 < 1.5, whereas 13/16 (81%) of the quiescent galaxies are compact. The number density of compact quiescent galaxies at z ∼ 4 is 1.8 +/- 0.8 × 10-5 Mpc-3 and increases rapidly, by < 5× , between 2 < z < 4. The paucity of compact star-forming galaxies at z ∼ 4 and their large rest-frame UV median sizes suggest that the formation phase of compact cores is very short and/or highly dust obscured. This paper contains data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

3 JUN 2015

THE DIFFERENTIAL SIZE GROWTH OF FIELD AND
CLUSTER GALAXIES AT z = 2.1 USING THE ZFOURGE SURVEY

THE ASTROPHYSICAL JOURNAL, 806, 3 (2015)

We investigate the differences in star-forming and quiescent galaxy properties as a function of environment at z = 2.1

JOURNAL PAPER Allen, R.J., et al. [16 authors, including Cowley, M. J.]
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THE DIFFERENTIAL SIZE GROWTH OF FIELD AND CLUSTER GALAXIES AT z = 2.1 USING THE ZFOURGE SURVEY

Allen, R.J., et al. [16 authors, including Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

There is ongoing debate regarding the extent that environment affects galaxy size growth beyond z > 1. To investigate the differences in star-forming and quiescent galaxy properties as a function of environment at z = 2.1, we create a mass-complete sample of 59 cluster galaxies Spitler et al. (2012) and 478 field galaxies with log(M) > 9 using photometric redshifts from the ZFOURGE survey. We compare the mass-size relation of field and cluster galaxies using measured galaxy semi-major axis half-light radii (r1/2,maj) from CANDELS HST/F160W imaging. We find consistent mass normalized (log(M) = 10.7) sizes for quiescent field galaxies (r1/2,maj = 1.81 +/- 0.29 kpc) and quiescent cluster galaxies (r1/2,maj = 2.17 +/- 0.63 kpc). The mass normalized size of star-forming cluster galaxies (r1/2,maj = 4.00 +/- 0.26 kpc ) is 12% larger (KS test 2.1σ) than star-forming field galaxies (r1/2,maj = 3.57 +/- 0.10 kpc). From the mass-color relation we find that quiescent field galaxies with 9.7 < log(M) < 10.4 are slightly redder (KS test 3.6σ) than quiescent cluster galaxies, while cluster and field quiescent galaxies with log(M) > 10.4 have consistent colors. We find that star-forming cluster galaxies are on average 20% redder than star-forming field galaxies at all masses. Furthermore, we stack galaxy images to measure average radial color profiles as a function of mass. Negative color gradients are only present for massive star-forming field and cluster galaxies with log(M) > 10.4, the remaining galaxy masses and types have flat profiles. Our results suggest given the observed differences in size and color of star-forming field and cluster galaxies, that the environment has begun to influence/accelerate their evolution. However, the lack of differences between field and cluster quiescent galaxies indicates that the environment has not begun to significantly influence their evolution at z ∼ 2.

9 APR 2015

ZFOURGE/CANDELS: ON THE EVOLUTION OF M*
GALAXY PROGENITORS FROM z = 3 TO 0.5

THE ASTROPHYSICAL JOURNAL, 803, 26 (2015)

Galaxies with stellar masses near M* contain the majority of stellar mass in the universe, and are therefore of special interest in the study of galaxy evolution. We study the typical progenitors of these galaxies using the FOURSTAR Galaxy Evolution Survey (ZFOURGE).

JOURNAL PAPER Papovich, C., et al. [41 authors, including Cowley, M. J.]
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ZFOURGE/CANDELS: ON THE EVOLUTION OF M* GALAXY PROGENITORS FROM z = 3 TO 0.5

Papovich, C., et al. [41 authors, including Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

Galaxies with stellar masses near M* contain the majority of stellar mass in the universe, and are therefore of special interest in the study of galaxy evolution. The Milky Way (MW) and Andromeda (M31) have present-day stellar masses near M*, at 5 × 1010 M (defined here to be MW-mass) and 1011 M (defined to be M31-mass). We study the typical progenitors of these galaxies using the FOURSTAR Galaxy Evolution Survey (ZFOURGE). ZFOURGE is a deep medium-band near-IR imaging survey, which is sensitive to the progenitors of these galaxies out to z ∼ 3. We use abundance-matching techniques to identify the main progenitors of these galaxies at higher redshifts. We measure the evolution in the stellar mass, rest-frame colors, morphologies, far-IR luminosities, and star formation rates, combining our deep multiwavelength imaging with near-IR Hubble Space Telescope imaging from Cosmic Near-IR Deep Extragalactic Legacy Survey (CANDELS), and Spitzer and Herschel far-IR imaging from Great Observatories Origins Deep Survey-Herschel and CANDELS-Herschel. The typical MW-mass and M31-mass progenitors passed through the same evolution stages, evolving from blue, star-forming disk galaxies at the earliest stages to redder dust-obscured IR-luminous galaxies in intermediate stages and to red, more quiescent galaxies at their latest stages. The progenitors of the MW-mass galaxies reached each evolutionary stage at later times (lower redshifts) and with stellar masses that are a factor of two to three lower than the progenitors of the M31-mass galaxies. The process driving this evolution, including the suppression of star formation in present-day M* galaxies, requires an evolving stellar-mass/halo-mass ratio and/or evolving halo-mass threshold for quiescent galaxies. The effective size and SFRs imply that the baryonic cold-gas fractions drop as galaxies evolve from high redshift to z ∼ 0 and are strongly anticorrelated with an increase in the Sérsic index. Therefore, the growth of galaxy bulges in M* galaxies corresponds to a rapid decline in the galaxy gas fractions and/or a decrease in the star formation efficiency.

2 APR 2015

THE ABSENCE OF AN ENVIRONMENTAL DEPENDENCE
IN THE MASS-METALLICITY RELATION AT z = 2

THE ASTROPHYSICAL JOURNAL LETTERS, 802, L26 (2015)

We investigate the environmental dependence of the mass-metallicity relation at z = 2 with MOSFIRE/Keck as part of the ZFIRE survey.

JOURNAL PAPER Kacprzak, G. G., et al. [13 authors, including Cowley, M. J.]
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THE ABSENCE OF AN ENVIRONMENTAL DEPENDENCE IN THE MASS-METALLICITY RELATION AT z = 2

Kacprzak, G. G., et al. [13 authors, including Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We investigate the environmental dependence of the mass-metallicity relation at z = 2 with MOSFIRE/Keck as part of the ZFIRE survey. Here, we present the chemical abundance of a Virgo-like progenitor at z = 2.095 that has an established red sequence. We identified 43 cluster (<z> = 2.095 +/- 0.004) and 74 field galaxies (<z> = 2.195 +/- 0.083) for which we can measure metallicities. For the first time, we show that there is no discernible difference between the mass-metallicity relation of field and cluster galaxies to within 0.02 dex. Both our field and cluster galaxy mass-metallicity relations are consistent with recent field galaxy studies at z ∼ 2. We present hydrodynamical simulations for which we derive mass-metallicity relations for field and cluster galaxies. We find at most a 0.1 dex offset toward more metal-rich simulated cluster galaxies. Our results from both simulations and observations suggest that environmental effects, if present, are small and are secondary to the ongoing inflow and outflow processes that are governed by galaxy halo mass.

21 AUG 2014

THE DISTRIBUTION OF SATELLITES AROUND MASSIVE GALAXIES AT 1 < z < 3 IN ZFOURGE/CANDELS: DEPENDENCE ON STAR FORMATION ACTIVITY

THE ASTROPHYSICAL JOURNAL, 792, 103 (2014)

We study the statistical distribution of satellites around star-forming and quiescent central galaxies at 1 < z < 3 using imaging from the FourStar Galaxy Evolution Survey and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey.

JOURNAL PAPER Kawinwanichakij, L., et al. [26 authors, including Cowley, M. J.]
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THE DISTRIBUTION OF SATELLITES AROUND MASSIVE GALAXIES AT 1 < z < 3 IN ZFOURGE/CANDELS: DEPENDENCE ON STAR FORMATION ACTIVITY

Kawinwanichakij, L., et al. [26 authors, including Cowley, M. J.] JOURNAL PAPER ASTROPHYSICS

We study the statistical distribution of satellites around star-forming and quiescent central galaxies at 1 < z < 3 using imaging from the FourStar Galaxy Evolution Survey (ZFOURGE) and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). The deep near-IR data select satellites down to log(M/M) > 9 at z < 3. The radial satellite distribution around centrals is consistent with a projected NFW profile. Massive quiescent centrals, log(M/M) > 10.78, have ∼2 times the number of satellites compared to star-forming centrals with a significance of 2.7σ even after accounting for differences in the centrals' stellar-mass distributions. We find no statistical difference in the satellite distributions of intermediate-mass quiescent and star-forming centrals, 10.48 < log(M/M) < 10.78. Comparing to the Guo2011 semi-analytic model, the excess number of satellites indicates that quiescent centrals have halo masses 0.3 dex larger than star-forming centrals, even when the stellar-mass distributions are fixed. We use a simple toy model that relates halo mass and quenching, which roughly reproduces the observed quenched fractions and the differences in halo mass between star-forming and quenched galaxies only if galaxies have a quenching probability that increases with halo mass from ∼0 for log(M/M) ∼11 to ∼1 for log(M/M) ∼13.5. A single halo-mass quenching threshold is unable to reproduce the quiescent fraction and satellite distribution of centrals. Therefore, while halo quenching may be an important mechanism, it is unlikely to be the only factor driving quenching. It remains unclear why a high fraction of centrals remain star-forming even in relatively massive halos.

13 JAN 2014

CHARACTERISING TRANSITING EXOPLANETS BY WAY
OF DIFFERENTIAL PHOTOMETRY

PHYSICS EDUCATION, 49, 293 (2014)

This paper describes a simple activity for plotting and characterizing the light curve from an exoplanet transit event by way of differential photometry analysis.

JOURNAL PAPER Cowley, M. J., Hughes, S. W.
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CHARACTERISING TRANSITING EXOPLANETS BY WAY OF DIFFERENTIAL PHOTOMETRY

Cowley, M. J., Hughes, S. W. JOURNAL PAPER EDUCATION

This paper describes a simple activity for plotting and characterizing the light curve from an exoplanet transit event by way of differential photometry analysis. Using free digital imaging software, participants analyse a series of telescope images with the goal of calculating various exoplanet parameters, including size, orbital radius and habitability. The activity has been designed for a high-school or undergraduate university level and introduces fundamental concepts in astrophysics and an understanding of the basis for exoplanetary science, the transit method and digital photometry.

01 MAY 2013

TESTING THE ACCURACY OF LUMINANCE MAPS ACQUIRED BY SMART PHONE CAMERAS

PROCEEDINGS OF THE CIE CENTENARY CONFERENCE, PARIS,
PP. 951-955. (2013)

This paper looks at the accuracy of using the built-in camera of smart phones and free software as an economical way to quantify and analyse light exposure by producing luminance maps from High Dynamic Range (HDR) images.

CONFERENCE Garcia-Hansen, V., et al. [4 authors including Cowley, M. J.]
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TESTING THE ACCURACY OF LUMINANCE MAPS ACQUIRED BY SMART PHONE CAMERAS

Garcia-Hansen, V., et al. [4 authors including Cowley, M. J.] CONFERENCE LIGHTING PHYSICS

This paper looks at the accuracy of using the built-in camera of smart phones and free software as an economical way to quantify and analyse light exposure by producing luminance maps from High Dynamic Range (HDR) images. HDR images were captured with an Apple iPhone 4S to capture a wide variation of luminance within an indoor and outdoor scene. The HDR images were then processed using Photosphere software (Ward, 2010.) to produce luminance maps, where individual pixel values were compared with calibrated luminance meter readings. This comparison has shown an average luminance error of ∼8% between the HDR image pixel values and luminance meter readings, when the range of luminances in the image is limited to approximately 1,500cd/m2.

.05

CONFERENCES

CONFERENCES AND SYMPOSIA
30 OCT 2018

ASTRO3D GALAXY EVOLUTION WORKSHOP

UNIVERSITY OF NEW SOUTH WALES

Participant at UNSW's Astro3D Galaxy Evolution Workshop

WORKSHOP  Sydney, Australia
01 DEC 2016

MOUNT STROMLO STUDENT SEMINARS

AUSTRALIAN NATIONAL UNIVERSITY

Contributed Talk, "The Milkyway's SMBH: Mostly Harmless?"

SEMINAR  Canberra, Australia
10 OCT 2016

UQ ASTROGROUP SEMINAR

UNIVERSITY OF QUEENSLAND

Invited Talk, "Investigating the Impact of SMBHs on their Host Galaxies with the ZFOURGE Survey"

SEMINAR  Brisbane, Australia
12 OCT 2016

USQ ASTROMEETING

UNIVERSITY OF SOUTHERN QUEENSLAND

Invited Talk, "Investigating the Impact of SMBHs on their Host Galaxies with the ZFOURGE Survey"

SEMINAR  Toowoomba, Australia
31 AUG 2016

TAIPAN SURVEY MEETING

AUSTRALIAN ASTRONOMICAL OBSERVATORY

Contributed Talk, "Investigating the Impact of SMBHs on their Host Galaxies with the ZFOURGE Survey"

WORKSHOP  Sydney, Australia
16 AUG 2016

NORTHERN SYDNEY ASTRONOMICAL SOCIETY
GENERAL MEETING

SAINT IGNATIUS' COLLEGE

Invited Talk, "Investigating the Co-evolution of Supermassive Black Holes and their Host Galaxies with the ZFOURGE Survey"

SEMINAR  Sydney, Australia
5 JUL 2016

ANNUAL SCIENTIFIC MEETING OF THE ASA

UNIVERSITY OF SYDNEY

Contributed Talk, "The Star Formation-AGN Connection in IR-bright Active Galaxies"

CONFERENCE  Sydney, Australia
27 JUN 2016

ESO CONFERENCE:
ACTIVE GALACTIC NUCLEI WHAT'S IN A NAME?

EUROPEAN SOUTHERN OBSERVATORY

Poster, "A Multiwavelength View of Enhanced Star-Formation in Active Galaxies"

CONFERENCE  Garching, Germany
16 MAY 2016

ZFIRE SURVEY MEETING

SWINBURNE UNIVERSITY

Participant at the ZFIRE Spectroscopic Survey Meeting

WORKSHOP  Melbourne, Australia
3 JAN 2016

ZFIRE SURVEY MEETING & OBSERVING RUN

W. M. KECK OBSERVATORY

Participant and Observer at the ZFIRE Spectroscopic Survey Meeting & Observing Run

WORKSHOP  Hawaii, USA
2 DEC 2015

CSIRO ASTRONOMY AND SPACE SCIENCE BOLTON SYMPOSIUM

CSIRO ASTRONOMY AND SPACE SCIENCE HEADQUARTERS

Contributed Talk, "The Impact of Active SMBHs on their Host Galaxies"

CONFERENCE  Sydney, Australia
17 NOV 2015

AUSTRALIAN INSTITUTE OF PHYSICS ANNUAL POSTGRADUATE AWARDS

TRINITY GRAMMAR SCHOOL

Contributed Talk, "Do Supermassive Black Holes Impact a Galaxy's Ability to Form New Stars?"

CONFERENCE  Sydney, Australia
25 OCT 2015

ZFOURGE SURVEY MEETING

TEXAS A&M UNIVERSITY

Contributed Talk, "The Long Road to Quiescence: A Story of AGN Feedback"

WORKSHOP  College Station, USA
12 OCT 2015

AUSTRALIAN TELESCOPE LARGE AREA SURVEY
(ATLAS) MEETING

CSIRO ASTRONOMY AND SPACE SCIENCE HEADQUARTERS

Invited Talk, "The Properties of X-ray, IR and Radio AGN Hosts to z = 3.2 in ZFOURGE"

SEMINAR  Sydney, Australia
14 AUG 2015

MACQUARIE UNIVERSITY AAASTRO SEMINARS

MACQUARIE UNIVERSITY

Contributed Talk, "The Long Road to Quiescence: A Story of AGN Feedback"

SEMINAR  Sydney, Australia
6 JUL 2015

ANNUAL SCIENTIFIC MEETING OF THE ASA

RYDGES ESPLANADE HOTEL

Contributed Talk, "Tracing the Star Formation Activity of AGN Host Galaxies in ZFOURGE"

CONFERENCE  Fremantle, Australia
1 JUL 2015

ZFIRE SURVEY MEETING

LYNDOCH HILL

Participant at the ZFIRE Spectroscopic Survey Meeting

WORKSHOP  Barossa Valley, Australia
1 JUL 2015

AAO CONFERENCE:
THE MOST MASSIVE GALAXIES AND THEIR PRECURSORS

LUNA PARK

Participant at the AAO's Conference, "The Most Massive Galaxies and their Precursors"

CONFERENCE  Sydney, Australia
22 MAY 2015

AUSTRALIAN GEMINI, MAGELLAN AND KECK SCIENCE SYMPOSIUM

AUSTRALIAN ASTRONOMICAL OBSERVATORY

Contributed Talk, "Highlights from The FourStar Galaxy Evolution Survey (ZFOURGE)"

CONFERENCE  Sydney, Australia
6 MAR 2015

ASTRONOMICAL SOCIETY OF NSW ORDINARY MEETING

EPPING CREATIVE CENTRE

Invited Talk, "A Multi-Wavelength Study on the Impact of SMBHs on Their Host Galaxies"

SEMINAR  Sydney, Australia
12 DEC 2014

MACQUARIE UNIVERSITY AAASTRO SEMINARS

MACQUARIE UNIVERSITY

Contributed Talk, "A Multi-Wavelength Study on the Impact of SMBHs on Their Host Galaxies"

SEMINAR  Sydney, Australia
29 OCT 2014

ZFOURGE SURVEY MEETING

TEXAS A&M UNIVERSITY

Contributed Talk, "A Study of Radio, X-ray, and Infrared Selected AGN in ZFOURGE"

WORKSHOP  College Station, USA
26 SEP 2014

ZFIRE SURVEY MEETING

SWINBURNE UNIVERSITY

Contributed Talk, "A Multi-Wavelength View of AGN Evolution"

WORKSHOP  Melbourne, Australia
23 JUL 2014

ANNUAL SCIENTIFIC MEETING OF THE ASA

MACQUARIE UNIVERSITY

Poster, "The Evolution of Massive AGN Host Galaxies to z ∼ 4 with ZFOURGE"

CONFERENCE  Sydney, Australia
21 JUL 2014

ASA HARLEY WOOD SCHOOL OF ASTRONOMY

MACQUARIE UNIVERSITY

Participant at the ASA Harley Wood School of Astronomy

WORKSHOP  Sydney, Australia
15 JUN 2014

CSIRO CONFERENCE:
POWERFUL AGN AND THEIR HOST GALAXIES

SHERATON PORT DOUGLAS

Poster, The Cosmological Evolution of AGN Host Galaxies to Redshift z ∼ 4 with ZFOURGE

CONFERENCE  Port Douglas, Australia
15 APR 2014

ZFOURGE SURVEY MEETING

MACQUARIE UNIVERSITY

Contributed Talk, "Active Galactic Nuclei in the FourStar Galaxy Evolution Survey (ZFOURGE)"

WORKSHOP  Sydney, Australia
15 APR 2014

AUSGO/AAO OBSERVATIONAL TECHNIQUES
WORKSHOP

AUSTRALIAN ASTRONOMICAL OBSERVATORY

Participant at the AusGO/AAO Observational Techniques Workshop

WORKSHOP  Sydney, Australia
01 DEC 2013

MOUNT STROMLO STUDENT SEMINARS

AUSTRALIAN NATIONAL UNIVERSITY

Participant at the RSAA's Mt. Stromlo Student Seminars

SEMINAR  Canberra, Australia
.06

OUTREACH

MEDIA COVERAGE
01 MAR 2018

THE MILKY WAY’S SUPERMASSIVE BLACK HOLE:
A HARBINGER OF DOOM?

AUSTRALASIAN SCIENCE MAGAZINE

Contrary to popular belief, new work from an Australian-led study suggests that supermassive black holes may not be starving galaxies like the Milky Way to death.

MAGAZINE ARTICLE
30 OCT 2017

BLACK HOLES COULD HELP SPARK NEW LIFE

ABC'S THE WORLD TODAY

Black holes are thought to destroy everything in its path, starving galaxies of the material needed to make new stars. However new Australian research shows black holes may not be as hungry as first believed.

RADIO INTERVIEW
30 OCT 2017

OUR GALAXYS BLACK HOLE NOT AS DEADLY AS FIRST THOUGHT

MACQUARIE UNIVERSITY NEWSROOM

A new study published in Monthly Notices of the Royal Astronomical Society has indicated that, contrary to past works, supermassive black holes are not responsible for starving their host galaxies to death.

NEWS ARTICLE
30 SEP 2016

THE BIG PICTURE OF THE UNIVERSE REVEALS
THE FAMILY TREE OF GALAXIES

THE CONVERSATION

A new photo album made from hundreds of images of more than 70,000 galaxies represents one of the most detailed galaxy studies ever compiled, spanning a period of 12 billion years.

NEWS ARTICLE
1 SEP 2016

GALAXY CENSUS REVEALS YOUNG GALAXIES WERE SURPRISINGLY ADVANCED FOR THEIR AGE

THE DAILY TELEGRAPH

Measuring the pulse of 70,000 galaxies has revealed many were alive and kicking — and even dancing — as little as three billion years after the Big Bang.

NEWS ARTICLE
31 AUG 2016

INTERNATIONAL STUDY CHARTS THE RISE AND
FALL OF GALAXIES

MACQUARIE UNIVERSITY NEWSROOM

In what is the most precise study of the distant universe ever conducted, Macquarie University and an international team of astronomers measured the distances and energy output of more than 70,000 galaxies over the past 12 billion years.

NEWS ARTICLE
29 FEB 2016

BLACK HOLES ARE LIFE-GIVERS, NOT DESTROYERS

THE AUSTRALIAN

Black holes could be life-givers rather than star-guzzling cisterns, after an Australian-led study put a new spin on the vacuum cleaners of the cosmos.

NEWS ARTICLE
OUTREACH ACTIVITIES

11 JAN 2017

CAN BLACK HOLES SHINE?

CONOCOPHILLIPS SCIENCE EXPERIENCE

A talk on black holes to high school students attending the ConocoPhillips Science Experience at Macquarie University.

PUBLIC TALK
20 OCT 2016

WHERE DO YOU FIND SCIENTISTS?

CARLINGFORD WEST

A professional development workshop for teachers as part of the Opening Real Science (ORS) program.

WORKSHOP
11 OCT 2016

ILLUMINATING BLACK HOLES

ROSEVILLE COLLEGE

A talk on black holes to high school students at Roseville College School as part of CSIRO's Scientists in School program.

SCHOOL TALK
2 AUG 2016

GRAVITATIONAL WAVES: WRINKLES IN SPACE TIME

ROSEVILLE COLLEGE

A talk on gravitational waves to high school students at Roseville College School as part of CSIRO's Scientists in School program.

SCHOOL TALK
14 MAY 2016

ILLUMINATING BLACK HOLES

MACQUARIE UNIVERSITY ASTRONOMY OPEN NIGHT

A talk on black holes to the public as part of Macquarie University's Astronomy Open Night. Click here for a recording.

PUBLIC TALK
14 MAY 2016

APPROACHES AND STRATEGIES FOR BRINGING
RECENT SCIENTIFIC DISCOVERIES INTO THE
CLASSROOM

MACQUARIE UNIVERSITY ASTRONOMY OPEN AFTERNOON

A professional development workshop for teachers as part of the Macquarie University Astronomy Open Afternoon.

WORKSHOP
11 MAY 2016

CAN BLACK HOLES SHINE?

MACQUARIE UNIVERSITY ART GALLERY

A talk on black holes to the public as part of the "Light Years Ahead Exhibition" held at the Macquarie University Art Gallery.

PUBLIC TALK
8 SEP 2015

CAN BLACK HOLES SHINE?

ST ALOYSIUS' COLLEGE

A talk on black holes to high school students at St Aloysius' College as part of Macquarie University's outreach efforts.

SCHOOL TALK
28 JUL 2015

CAN BLACK HOLES SHINE?

ROSEVILLE COLLEGE

A talk on black holes to high school students at Roseville College School as part of CSIRO's Scientists in School program.

SCHOOL TALK
23 MAY 2015

CAN BLACK HOLES SHINE?

MACQUARIE UNIVERSITY ASTRONOMY OPEN NIGHT

A talk on black holes to the public as part of Macquarie University's Astronomy Open Night.

PUBLIC TALK
11 JAN 2015

HUNTING FOR ALIEN WORLDS: HOW TO FIND EXOPLANETS

CONOCOPHILLIPS SCIENCE EXPERIENCE

A workshop on exoplanets to high school students attending the ConocoPhillips Science Experience at Macquarie University.

WORKSHOP
4 APR 2014

HUNTING FOR ALIEN WORLDS: HOW TO FIND EXOPLANETS

MACQUARIE UNIVERSITY ASTRONOMY OPEN NIGHT

A talk on exoplanets to the public as part of Macquarie University's Astronomy Open Night.

PUBLIC TALK
21 JUN 2013

HUNT FOR NEW WORLDS

QUEENSLAND UNIVERSITY OF TECHNOLOGY STEM CAMP

A workshop on exoplanets to students as part of the QUT Vice-Chancellor's STEM Camp.

WORKSHOP
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PHOTOS

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Sydney, Australia

Lecturing at Macquarie University

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Garching, Germany

ESO AGN Workshop

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Hawaii, USA

Keck Visit on Maunakea

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Sydney, Australia

Recording for Documentary

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Sydney, Australia

My Office at Macquarie

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Sydney, Australia

The TAIPAN Instrument

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Sydney, Australia

Public Lecture

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Hawaii, USA

Observing Night on Keck

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Port Douglas, Australia

CSIRO AGN Conference

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Barossa Valley, Australia

The ZFIRE Team

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Sydney, Australia

Public Lecture

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Sydney, Australia

Recoding for Opening Real Science

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Sydney, Australia

Public Talk at Macquarie
Art Gallery

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Sydney, Australia

Lecture for ConocoPhillips Science Experience

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Sydney, Australia

Gemini, Magellan, and Keck Symposium

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Hawaii, USA

Keck Visit

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Sydney, Australia

Demonstrating for Introductory Astronomy

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Sydney, Australia

CSIRO Observing Desk

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CONTACT

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