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Galaxy Properties in MACSJ0717.53745 as a Function of Cluster Environment

Introduction. Galaxy Cluster EnvironmentMostly red, passively evolving galaxiesButcher-Oemler effectBlue field galaxies added over timeQuenched Star FormationRam StrippingHarassment/CollisionsStrangulation. Introduction. Z=0.545Most Disturbed Cluster known at z>0.5One of most massive clusters at z>0.5Dynamic activity on many spatial scales: filaments, cluster mergers.

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Galaxy Properties in MACSJ0717.53745 as a Function of Cluster Environment

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    1. Galaxy Properties in MACSJ0717.5+3745 as a Function of Cluster Environment Jeff Rich Adviser: Harald Ebeling

    2. Introduction Galaxy Cluster Environment Mostly red, passively evolving galaxies Butcher-Oemler effect Blue field galaxies added over time Quenched Star Formation Ram Stripping Harassment/Collisions Strangulation

    3. Introduction Z=0.545 Most Disturbed Cluster known at z>0.5 One of most massive clusters at z>0.5 Dynamic activity on many spatial scales: filaments, cluster mergers

    4. Data ACS data in two bands: F606W, F814W 3 x 6 pointings 10 X 20 arcmin, 3.8 x 7.6 Mpc Used to investigate color Keck/DEIMOS spectra ~700 spectra in ACS field

    5. Data

    6. Data Analysis SExtractor Source Detection with F814W image Magnitudes calculated in both bands Kron aperture & Fixed aperture Object Selection HST sources correlated with DEIMOS spectra Cluster members spectroscopically selected using DEIMOS spectra

    7. Data Analysis Stars/Galaxies flagged Catalog cleaned for I814 < 22.5 Maximum spectroscopic completeness for I814 < 21.2

    8. Map of Cluster Members 434 Spectroscopically confirmed cluster members covering wide spatial range

    9. Data Analysis Color Selection: Galaxies assigned “red” or “blue” status Blue galaxies: more recent or active star formation Color selection based on red sequence “Generous” and “Conservative” selection 2? and 1? width red sequences Blue galaxies 2? and 3? blueward of red sequence

    10. Data Analysis Color Selection: Galaxies assigned “red” or “blue” status Blue galaxies: more recent or active star formation Color selection based on red sequence “Generous” and “Conservative” selection 2? and 1? width red sequences Blue galaxies 2? and 3? blueward of red sequence

    11. Data Analysis

    12. Data Analysis

    13. Data Analysis 1-D color distribution: Investigate simple Color-Density relation Cluster members assigned clustercentric distance based on x-ray center Surface density of cluster members Fractional number of red or blue galaxies

    14. Data Analysis

    15. Data Analysis

    16. Data Analysis

    17. Data Analysis 2-D Color Distribution Investigate spatial distribution of color Manually binned 2-D histogram of all cluster members, minimum of 19 members/bin

    18. Data Analysis 2-D Color Distribution Generous Color Cut Red (top) or Blue (bottom) fractional number of galaxies per bin

    19. Data Analysis 2-D Color Distribution Conservative Color Cut Red (top) or Blue (bottom) fractional number of galaxies per bin

    20. Discussion Star formation quenched Mechanism? Unique features Red galaxies far from cluster core Blue galaxies in filament Blue galaxies in outskirts Match field?

    21. Future Work Photo z/incompleteness Morphological concerns Unique to HST Quantitative SF diagnostics

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