Stéphane Arnouts David Schiminovich Olivier Ilbert and VVDS and GALEX teams THE GALEX-VVDS DEEP SURVEYS : Evolution of the Far UV luminosity Function and Density (+ SFR) up to z=1.5 PI : Chris Martin (Caltech) PI : O. LeFèvre (Marseille) G. Vettolani (Bologna)

One of the principal goal of GALEX Evolution of the SFR density up to z=1.5 UV sensitive measurement of the ongoing Star Formation Used to derive SFRD: locally (z<0.2, FOCA) at high-z (z>2.5, in optical band) GALEX fills the gap where most of the SFR evolution is seen Required DEEP and WIDE GALEX observations DEEP and WIDE optical spectro-photometry observations

Outline of the talk : Results from a PILOT STUDY done in the 2hr field : GALEX Deep obervations VVDS Deep spectroscopy and photometry Spectroscopic sample : Evolution of the FUV LF and LD Implication in the SFR history Morphology of a sub-sample of UV luminous galaxies Recent Photo-z analyses : Combined dataset : VVDS+CFHTLS+SWIRE

Jan 11, 2005AAS DS Texp = sec FUV+NUV color image GALEX-02hr field Used area :  =0.027 Field of View1.2 degrees BandsFUV A NUV A [simultaneous] Angular resolution 4.5” FWHM

GALEX Galaxy Number counts NUV < Completeness correction with HST counts (Gardner et al. 2000)

Spectroscopic Area : 0.46 deg 2 The 2hr field combined dataset VVDS : BVRI (JK) VVDS : spectroscopy I AB =24 AND CFHTLS : ugriz SWIRE : 3.6 to 8  m +24  m (section photo-z) GALEX

Jan 11, 2005AAS DS NUV band 5” PSF GALEX - OPTICAL matches

Jan 11, 2005AAS DS GALEX - OPTICAL matches B band 1” PSF

GALEX - OPTICAL matches Counterparts searched in a distance = 4’’ :  ast = 0.7’’ PSF=5’’ but good astrometry ALL UV sources have an optical counterparts NUV<24.5 ~50% have a single optical counterparts NUV<24.5 ~35% have two optical counterparts NUV<24.5 ~15% have more than two optical counterparts

GALEX - OPTICAL matches Preliminary Analysis : UV sources matched with the closest OC which is in 90% cases the brightest one Impact of the blends based on : -1 : expected colors from single match -2 : apportion the UV flux among the multiple OCs using Sutherland & Sanders (1992) method overestimated by 0.25 mag for 2 OCs 0.50 mag for multiple OCs

GALEX with VVDS spectroscopy ~1100 Zspec 19.5<NUV<24.5 ~15% UV sample

Color distribution Spectro : Good sampling of UV sources. Saturation : 95% at z<0.2 (SDSS) I AB >24 : only 4% Saturation in I Limit spectro

Redshift distribution LF Unique OC <= 2 Ocs full sample with secure redshifts

FUV Luminosity Function with ~1000 Z-spectro (Arnouts, Schiminovich, Ilbert et al. 2005) Strong evolution from 0<z<1.2 (GALEX) FUV abs from NUV mag LF estimators : Vmax, C+, SWML, STY using ALF tool (Ilbert et al., 2004) Weight to account for : 1. Spectroscopic strategy 2. NUV counts completeness Local GALEX LF (Wyder et al., 2005)

FUV Luminosity Function at higher z (Arnouts, Schiminovich, Ilbert et al. 2005) Trend continues to z=3 (HDF) Zphot from HDF N+S (Arnouts et al., 1999 & 2002)  z to be FUV rest-frame : 1.75<Z<2.25 with F450< <Z<3.40 with F606< A (Steidel et al., 1999)

Evolution of the FUV Luminosity Function Arnouts, Schiminovich, Ilbert et al (2005) Possible evolution in slope Significant evolution 0 < z < 1 :  M * = 2 mag (or x6 in L * ) 1 < z < 3 :  M * = 1 mag

Evolution of FUV Luminosity Density Schiminovich, Ilbert, Arnouts et al. (2005) LD using ALF tool (1+z) 2.5 Integration of STY fit up to L=0 Sum of  (L).L.dL Using Vmax LF (1+z) 2.5 luminosity density evolution since z ~ 1 Continued slow evolution 1<z<3 GALEX AIS-MIS : Wyder et al GALEX DIS : This work HDF : Arnouts et al (99, 02) Steidel et al (1999) (1+z) 1.5 (1+z) 3.5

UV Luminous Galaxies (UVLGs) (DS, Ilbert, Arnouts et al) (1+z) 2.5 Luminosity density of UV luminous: L>0.2 L * (z=3) “LBG-like” galaxies shows dramatic evolution: (1+z) 5 Steeper than QSO LD evolution ( Boyle + Madau et al ) UVLGs produce a significant fraction of LD at z = 1 (25%) Total

Jan 11, 2005AAS DS Sizes of extreme UV-luminous galaxies L FUV,bol > 2x10 10 M sol SFR 5-50 M sol /yr Local : u-band r 1/2 (circles) Compact galaxies may be LBG analogs with high SFR/area and SFR/ Large Compact (Slide courtesy of D.S.) Local Measurement: GALEX-SDSS (Heckman, Hoopes et al, 2005) 0.55<z<0.8 : COSMOS M. Zamojski & D. Schiminovich V-band r 1/2 (squares) r 1/2 consistent with local sample & Locus slightly higher than for LBGs

Jan 11, 2005AAS DS Large UV Luminous Galaxies (UVLGs) r 50 ~10 kpc 0.55<z<0.8 (Slide courtesy of D.S.)

Jan 11, 2005AAS DS Compact UV Luminous Galaxies (UVLGs) r 50 ~2.5 kpc 0.55<z<0.8 (Slide courtesy of D.S.)

(Meurer et al.,1999 Kong et al., 2004) Dust attenuation correction Schiminovich, Ilbert, Arnouts et al. (2005) Using UV slope:  A FUV = f(  ) Full sample  consistent with - local FUV sample (Treyer et al., 2005) - high-z sample (Adelberger, 2000) FWHM(  )=1.4  (  )=0.4

Uncorrected SFR vs. Z NUV <24.5NUV <26 (UDIS) Conv. L FUV to SFR (Kennicutt, 1998) No dependence of dust attenuation A FUV with SFR uncor L * (z) As a consequence Schiminovich, Ilbert, Arnouts et al. (2005)

Corrected SFR vs. Z Conv. L FUV to SFR (Kennicutt, 1998) + A FUV (Meurer et al., 1999) Paucity of low A FUV galaxies with high SFR cor  - Large scatter in the measured A FUV  - Dust attenuation law  NUV=24.5 A FUV M99 relation may overestimate A FUV for star-forming galaxies Schiminovich, Ilbert, Arnouts et al. (2005)

Evolution of the SFR Density uncorrected and dust-corrected (hatched region) (1+z) 2.5 Wilson et al (2002) Lilly et al (1996) Sullivan et al (2000) Brinchmann Tresse and Maddox Perez-Gonzalez Gronwall Uncorrected SFRD Meas =1.8 Min A FUV =1.0 (local UV sample Buat et al. 2005) Corrected SFRD 0<z<1.5 :  = <z<3 :  =0.5 Consistent with H  measurements

Z photometric Area : 0.65 deg 2 VVDS : (U)BVRI (JK) Photometry used : VVDS : (U)BVRI(JK) CFHTLS : ugriz SWIRE :  m GALEX Photometric Reshifts in F02 field works by Ilbert, Arnouts, Budavari et al Classification in Galaxy/Star/QSO FUV LF with photo-z for a large sample

Photometric Reshifts of UV galaxies in F02 field Secure Zspec : 949 Colors : galaxy types Filled circles : 1 OC Open triangles : n OCs No systematic 0<z<1.2 Small scatter :  =0.04

VVDS : (U)BVRI (JK) Photometric Reshifts of UV galaxies in F02 field All Zspec : 1127 Colors : galaxy types Filled circles : 1 OC Open triangles : n OCs No systematic 0<z<1.2 Small scatter :  =0.05 Small number of outliers

VVDS : (U)BVRI (JK) Color-color checks vs classification (NUV-B) vs (B-I) Star/galaxy separation Galaxies below the line

VVDS : (U)BVRI (JK) Color-color checks vs classification (FUV-NUV) vs (B-I)

VVDS : (U)BVRI (JK) Color-color checks vs classification (B-I) vs ( ) Same QSOs and Stars regions for spec. and phot.

VVDS : (U)BVRI (JK) Galaxy Redshift distribution

FUV Luminosity Function with ~6000 Z-photo At z=1: no constraint on slope Consistent with  =-1.6

FUV Luminosity Function Zspec vs Zphot Consistent with LF(spec) Smaller errorbars At 0.2<z<0.4 : constraint on M *

FUV Luminosity Function Zspec vs Zphot No evolution in  0<z<0.8 Consistent M * (z) evolution Fixed 

Galaxy “Type” classification with Zspec (Arnouts, Schiminovich, Ilbert et al., 2005) Poggianti et al 1997 Apply to the Zphot sample Kinney et al;, Small number of galaxies redder than Sb -Degeneracy between old syst. and dusty SB (NUV-R) correlated with SFR current / past (Salim et al. 2005) : Galaxy SF history (B-I) correlates with (NUV-R) : (B-I) as a crude proxy for galaxy type

Galaxy “Type” classification with Zphot Type fraction vs Z (FUV<22, z<0.2) Increase of the unobscured SB class from z=0 to 1

Galaxy “Type” LF with Zphot

Similar evolution for the two reddest classes Stronger evolution of the SB class wrt red ones

Galaxy “Type” LF with Zphot  (z)~constant per type 2 Red classes : -0.9<  <-1.2 SB class : -1.5<  <-1.8 Modest luminosity evolution of SB class wrt reddest classes Number density evolution of the SB class

Conclusion GALEX-VVDS PILOT STUDY Global evolution of the FUV light of galaxies in 0<z<1.5 and LFs per type: strong increase in density of SB class Constraint on the evolution of the SFRD (uncorr.,corr.) A new class of UVLG at 0.5<z<1 (LBG analogs) in easy reach for optical follow-up NEAR FUTUR GALEX-VVDS-SWIRE : nice combined science (zphot, dust law, SFR vs Mass, AGN evolution,...) More deep field and a few deeper ( lower SFR sensitivity) SF sites vs LSS (UV / optical-IR cross-correlation)

Conclusion GALEX-VVDS PILOT STUDY Global evolution of the FUV light of galaxies in 0<z<1.5 and LFs per type: strong increase in density of SB class Constraint on the evolution of the SFRD (uncorr.,corr.) A new class of UVLG at 0.5<z<1 (LBG analogs) in easy reach for optical follow-up NEAR FUTUR GALEX-VVDS-SWIRE : nice combined science (zphot, dust law, SFR vs Mass, AGN evolution,...) More deep field and a few deeper ( lower SFR sensitivity) SF sites vs LSS (UV / optical-IR cross-correlation)