stéphane arnouts david schiminovich olivier ilbert and vvds and galex teams

Stéphane ArnoutsDavid SchiminovichOlivier 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

AAS 72.07 - DS Jan 11, 2005

Texp = 52765 sec

FUV+NUV color image

GALEX-02hr field

Used area :

<E(B-V)>=0.027

Field of View

1.2 degrees

Bands FUV 1350-1750 ANUV 1750-2800 A[simultaneous]

Angular resolution

4.5” FWHM

GALEX Galaxy Number counts

NUV < 24.5.Completenesscorrection withHST counts (Gardner et al. 2000)

Spectroscopic Area : 0.46 deg2

The 2hr field combined dataset

VVDS : BVRI (JK) VVDS : spectroscopy IAB=24

ANDCFHTLS : ugriz

SWIRE : 3.6 to 8m

+24m

(section photo-z)

GALEX

Jan 11, 2005AAS 72.07 - DS

NUV band5” PSF

GALEX - OPTICAL matches

Jan 11, 2005AAS 72.07 - DS

GALEX - OPTICAL matches B band1” 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

<UV flux> overestimated by 0.25 mag for 2 OCs0.50 mag for multiple OCs

GALEX with VVDS spectroscopy

~1100 Zspec19.5<NUV<24.5

~15% UV sample

Color distribution

Spectro : Good samplingof UV sources.

Saturation : 95% at z<0.2 (SDSS)

IAB>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 evolutionfrom 0<z<1.2 (GALEX)

FUVabs from NUV mag

LF estimators :Vmax, C+, SWML, STYusing 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<27

2.40<Z<3.40 with F606<27

1700A LF @z=3(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 DensitySchiminovich, 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.dLUsing Vmax LF

(1+z)2.5 luminositydensity evolutionsince z~1

Continued slowevolution 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 ofUV 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

AAS 72.07 - DS Jan 11, 2005

Sizes of extreme UV-luminous galaxies

LFUV,bol > 2x1010 Msol

SFR 5-50 Msol/yr

Local : u-band r1/2 (circles)

Compact galaxies may be LBG analogs with high SFR/area and SFR/<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 r1/2 (squares)

r1/2 consistent with local sample & Locus slightly higher than for LBGs

AAS 72.07 - DS Jan 11, 2005

Large UV Luminous Galaxies (UVLGs) r50~10 kpc 0.55<z<0.8

(Slide courtesy of D.S.)

AAS 72.07 - DS Jan 11, 2005

Compact UV Luminous Galaxies (UVLGs) r50~2.5 kpc 0.55<z<0.8

(Slide courtesy of D.S.)

(Meurer et al.,1999Kong et al., 2004)

Dust attenuation correctionSchiminovich, Ilbert, Arnouts et al. (2005)

Using UV slope: AFUV = 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 <24.5 NUV <26 (UDIS)

Conv. LFUV to SFR (Kennicutt, 1998)

No dependence ofdust attenuation AFUV

with SFRuncor

L*(z)As a consequence

Schiminovich, Ilbert, Arnouts et al. (2005)

Corrected SFR vs. Z

Conv. LFUV to SFR (Kennicutt, 1998)+ AFUV (Meurer et al., 1999)

Paucity of low AFUV

galaxies with

high SFRcor

- Large scatter in the

measured AFUV - Dust attenuation law

NUV=24.5AFUV

4.0

2.5

1.5 0.5 0.

M99 relation may overestimate AFUV 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 MaddoxPerez-GonzalezGronwall

Uncorrected SFRD

Meas <AFUV>=1.8Min AFUV=1.0(local UV sample Buat et al. 2005)

Corrected SFRD

0<z<1.5 : =2.51.2<z<3 : =0.5

Consistent withH measurements

Z photometric Area : 0.65 deg2

VVDS : (U)BVRI (JK)Photometry used :

VVDS : (U)BVRI(JK)CFHTLS : ugrizSWIRE : 3.6 +4.5m

GALEX

Photometric Reshifts in F02 field works by Ilbert , Arnouts, Budavari et al

Classification in Galaxy/Star/QSO

FUV LF with photo-zfor a large sample

Photometric Reshifts of UV galaxies in F02 field

Secure Zspec : 949

Colors : galaxy typesFilled circles : 1 OCOpen triangles : n OCs

No systematic 0<z<1.2Small scatter : =0.04

VVDS : (U)BVRI (JK)

Photometric Reshifts of UV galaxies in F02 field

All Zspec : 1127

Colors : galaxy typesFilled circles : 1 OCOpen triangles : n OCs

No systematic 0<z<1.2Small scatter : =0.05Small 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 (3.6-4.5)

Same QSOs and Stars regionsfor spec. and phot.

VVDS : (U)BVRI (JK)

Galaxy Redshift distribution

FUV Luminosity Function with ~6000 Z-photo

At z=1: no constraint on slopeConsistent 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;, 1996- Small number of galaxiesredder than Sb

-Degeneracy between old syst. and dusty SB

(NUV-R) correlated with SFRcurrent/ <SFR>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 unobscuredSB class from z=0 to 1

Galaxy “Type” LF with Zphot

Galaxy “Type” LF with Zphot

Galaxy “Type” LF with Zphot

Galaxy “Type” LF with Zphot

Similar evolution for the two reddest classesStronger 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 evolutionof 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)