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


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


•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)


(FUV-NUV) vs (B-I)

VVDS : (U)BVRI (JK)


(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


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


(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)

stéphane arnouts david schiminovich olivier ilbert and vvds and galex teams

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