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GALEX Galaxy Evolution Explorer An Ultraviolet Imaging and Spectroscopic Survey GALEX and COSMOS: Morphologies of Star- Forming Galaxies out to z~1 May 21, 2005 David Schiminovich Michel Zamojski Columbia University M. Rich UCLA + GALEX and COSMOS teams GALEX vs. COSMOS NUV I814W FUVFUV NUVI814W GALEX Bands z=0.7 FUV (1530 A) NUV (2310 A) GALEX FOV: 1.2 deg. diam PSF: 5” (FWHM) SSP - Bruzual and COSMOS KYOTO Charlot (2003) May 23, 2005 GALEX/COSMOS Field Deep Imaging Survey 01 03 Obs. Spring 2004 4 targets in region on 0.5 degree grid 50 ks each 100, 150, 200 ks in overlap regions mAB <25-26 02 04 COSMOS KYOTO 1.4O May 23, 2005 Observing Status - Spring 05 (IR1.1) Central pointing (COSMOS_00) • Shallow imaging (~3 ks processed) • Shallow grism spectroscopy (~20 ks) • candidate for deeper follow-up No additional COSMOS observations in Spring 05 • Schedule availability limited • Spectroscopy observations given lower priority • GALEX FUV detector off COSMOS KYOTO May 23, 2005 Processing Status - April 05 (IR1.1) Integration time on four fields (target was 50ks): COSMOS_01 - 44024 s COSMOS_02 - 44442 s COSMOS_03 - 41270 s COSMOS_04 - 44169 s (85-90% observed data passed checks) Catalog Refinements • Source confusion/deblending • Background Subtraction - faint source photometry • Significant progress has been made in these areas COSMOS KYOTO May 23, 2005 10’ COSMOS KYOTO May 23, 2005 GALEX/COSMOS Field Green Contours: GALEX NUV Image: COSMOS ACS COSMOS KYOTO May 23, 2005 GALEX Data Release Plan GALEX/COSMOS images and catalogs will be released to public as part of GALEX GR2 (second data release) in late Fall 2005 Pipeline outputs only Will also be provided to IRSA at that time GALEX has suffered serious funding cut, and FUV problems which affects our ability to process the COSMOS images. COSMOS KYOTO May 23, 2005 GALEX/COSMOS Catalog New GALEX/COSMOS matched catalog using latest COSMOS photo-z cat (05/2005) • Photometry using optical prior (positions only) • Michel Zamojski (grad student at Columbia) performing reduction/analysis • Can provide catalogs and images for COSMOS projects (or participation in analysis effort) upon request. COSMOS KYOTO May 23, 2005 GALEX/COSMOS Science GALEX+VVDS Schiminovich et al (2005) GALEX+SDSS - Seibert et al 2005 COSMOS KYOTO May 23, 2005 GALEX/COSMOS Science Nearly 100,000 galaxies have been detected by GALEX down to NUV~25.5 over the full field. COSMOS has no better tracer of SFR in the range 0<z<1 than the GALEX FUV and NUV observations (even w/ caveats of dust attenuation and SFH) COSMOS KYOTO May 23, 2005 Short-term GALEX/COSMOS Projects Morphological Properties of Star-Forming Galaxies at 0.5<z<1.0 using COSMOS/GALEX(Zamojski, DS, Rich et al) • Apj Letter part of Zamojski PhD thesis (also see next few slides) • Overall project combines other local and deep data sets. For this reason Michel has measured his own morphologies • Willing to distribute morph. catalog to team and/or use other morph. catalogs for some analysis • Comparison morphologies in ugriz have been measured using SDSS NYU low-z galaxy catalog (can also provide to team) GALEX Far and Near Ultraviolet Observations of the HST/COSMOS Survey Region (DS, Zamojski, Rich et al) • Basic description of GALEX observations, properties and initial analysis) Letter + Paper will be distributed to team/ready for submission in August COSMOS KYOTO May 23, 2005 GALEX/COSMOS Projects (~1 yr) • Morphological evolution of star-forming galaxies and the evolution of rest-frame ultraviolet luminosity function/density vs. morphological type. (Zamojski, DS, Rich, et al) • Physical properties of star-forming galaxies at 0.5<z<1.0 (Rich, Salim, DS, et al) • SFR/Mass vs. morphology (DS, Rich et al) • Morphological properties of galaxies at SF extremes (starburst/LBGs, ~k+a/red objects) (Rich, DS et al) • Evolution of UV extinction properties and dependence on morphological type, size. (would be excellent to combine w/ VLA/COSMOS, possibly X- ray and some Spitzer data) • Evolution of UV luminosity/SFR vs. density/local environment COSMOS KYOTO May 23, 2005 GALEX/COSMOS Analysis Over full 2 sq. deg: >75k GALEX matches w/ optical data NUV<25 Analysis for 1 sq. deg: (using Dec/Jan photo-z and Cycle 12 ACS data) High S/N I-limited sample with I<23 and good photo-zs (17k objects) NUV<25 (9k galaxies) Redshift Range: 0.55<z<0.8 Quantities measured: GALEX: MFUV, LFUV ACS: Morphology, r50 COSMOS KYOTO May 23, 2005 I. Morphology of FUV luminous vs. FUV faint galaxies at 0.55<z<0.8 Non-parametric morphologies: Concentration (C) B/D, Type Asymmetry (A) Merger Clumpiness (S) Star Formation Gini Coefficient (G) B/D, Type M20 (M20) B/D, Merger following work of Abraham et al (1996), Conselice (2003), Lotz et al (2004) •17000 total CASGM measurements from ACS/COSMOS data •5540 in redshift slice 0.55<z<0.8 COSMOS KYOTO May 23, 2005 I. Morphology of FUV luminous vs. FUV under luminous galaxies at 0.55<z<0.8 MFUV < -18 MFUV > -18 2.5k galaxies each bin II. Sizes of extreme UV-luminous galaxies Local Measurement: Heckman, Hoopes et al (2005) LFUV,bol > 2x1010 Msol SFR 5-50 Msol/yr Large SDSS u-band half-light radius (circles) Compact galaxies may Compact be LBG analogs with high SFR/area and SFR/<SFR> Large galaxies may be extreme disks COSMOS rest frame V-band half-light radius (squares) COSMOS KYOTO May 23, 2005 Compact UV Luminous Galaxies (UVLGs) r50~2.5 kpc 0.55<z<0.8 COSMOS KYOTO May 23, 2005 Large UV Luminous Galaxies (UVLGs) r50~10 kpc 0.55<z<0.8 COSMOS KYOTO May 23, 2005 Conclusions and Work in Progress • GALEX has performed deep imaging entire 2 sq. deg. COSMOS field • At 0.55<z<0.8, FUV luminous galaxies have higher Concentration, Clumpiness, Gini Coefficient, M20 (and somewhat higher Asymmetry) than their FUV faint counterparts. • At 0.55<z<0.8, UVLGs (extreme UV luminous galaxies) have half-light radii roughly consistent with range seen in local sample, where both compact and large galaxies are seen. Locus slightly higher than for typical LBG. Work in Progress • Further investigation into relation between morphology, SFR and mass and evolution w/ z. • Morphologies of local comparison sample Of General Interest … • GALEX photometry could be used to constrain better the photo z’s especially for star forming galaxies z<1.5 • Would be useful to have final throughput bandpasses as a function of for all optical/IR flux points >> Salim’s physical parameters (masses, SFR, etc.). Can this be made available on web site? • We could add these derived parameters to the data set. • Should a U-cosmos proposal to “finish” Galex photometry of the field and to add ~200 ksec of spectroscopy be proposed?
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