St

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PI Chris Martin (Caltech)
PI O. LeFèvre (Marseille) G. Vettolani
(Bologna)
THE GALEX-VVDS DEEP SURVEYS Evolution of the
Far UV luminosity Function and Density ( SFR)
up to z1.5
Stéphane Arnouts David Schiminovich Olivier
Ilbert and VVDS and GALEX teams
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• One of the principal goal of GALEX
• Evolution of the SFR density up to z1.5
• UV sensitive measurement of the ongoing Star
  Formation
• Used to derive SFRD
• locally (zlt0.2 , FOCA)
• at high-z (zgt2.5, 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

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• 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 VVDSCFHTLSSWIRE

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GALEX-02hr field
Field of View 1.2 degrees
Bands FUV 1350-1750 A NUV 1750-2800 A simultaneous
Angular resolution 4.5 FWHM
Used area ?????
FUVNUV color image
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GALEX Galaxy Number counts
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The 2hr field combined dataset
VVDS BVRI (JK) VVDS spectroscopy
IAB24
GALEX
AND CFHTLS ugriz SWIRE 3.6 to 8?m 24?m
(section photo-z)
Spectroscopic Area 0.46 deg2
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NUV band5 PSF
GALEX - OPTICAL matches
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B band1 PSF
GALEX - OPTICAL matches
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GALEX - OPTICAL matches
PSF5 but good astrometry
Counterparts searched in a distance 4
?ast 0.7

• ALL UV sources have an optical counterparts

• NUVlt24.5 50 have a single optical counterparts

• NUVlt24.5 35 have two optical counterparts

• NUVlt24.5 15 have more than two optical
  counterparts

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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

ltUV fluxgt overestimated by 0.25 mag for 2
OCs 0.50 mag for multiple OCs
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GALEX with VVDS spectroscopy
1100 Zspec 19.5ltNUVlt24.5 15 UV sample
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Color distribution
Saturation in I
Spectro Good sampling of UV sources. Saturatio
n 95 at zlt0.2 (SDSS) IABgt24 only 4
Limit spectro
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Redshift distribution
with secure redshifts
Unique OC lt 2 Ocs full sample
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FUV Luminosity Function with 1000 Z-spectro
(Arnouts, Schiminovich, Ilbert et al. 2005)

• FUVabs from NUV mag
• LF estimators
• Vmax, C, SWML, STY
• using ALF tool
• (Ilbert et al., 2004)
• Weight to account for
• Spectroscopic strategy
• NUV counts completeness

Local GALEX LF (Wyder et al., 2005)
Strong evolution from 0ltzlt1.2 (GALEX)
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FUV Luminosity Function at higher z (Arnouts,
Schiminovich, Ilbert et al. 2005)
Zphot from HDF NS (Arnouts et al., 1999
2002) ?z to be FUV rest-frame 1.75ltZlt2.25
with F450lt27 2.40ltZlt3.40 with F606lt27
1700A LF _at_z3 (Steidel et al., 1999)
Trend continues to z3 (HDF)
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Evolution of the FUV Luminosity Function
Arnouts, Schiminovich, Ilbert et al (2005)
Possible evolution in slope
Significant evolution 0 lt z lt 1 ?M 2
mag (or x6 in L) 1 lt z lt 3 ?M
1 mag
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Evolution of FUV Luminosity DensitySchiminovich,
Ilbert, Arnouts et al. (2005)
LD using ALF tool
(1z)3.5
(1z)2.5
(1z)1.5
(1z)2.5 luminosity density evolution since
z1 Continued slow evolution 1ltzlt3
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UV Luminous Galaxies (UVLGs)(DS, Ilbert, Arnouts
et al)

• Luminosity density of
• UV luminous Lgt0.2 L(z3)
• LBG-like galaxies shows
• dramatic evolution (1z)5
• Steeper than QSO
• LD evolution
• (Boyle Madau et al)
• UVLGs produce a
• significant fraction of LD
• at z 1 (25)

Total
(1z)2.5
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Sizes of extreme UV-luminous galaxies
(Slide courtesy of D.S.)
Local Measurement GALEX-SDSS (Heckman, Hoopes
et al, 2005)
LFUV,bol gt 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/ltSFRgt
Large
Compact
0.55ltzlt0.8 COSMOS M. Zamojski D.
Schiminovich V-band r1/2 (squares) r1/2
consistent with local sample Locus slightly
higher than for LBGs
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Large UV Luminous Galaxies (UVLGs) r5010
kpc 0.55ltzlt0.8
(Slide courtesy of D.S.)
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Compact UV Luminous Galaxies (UVLGs) r502.5
kpc 0.55ltzlt0.8
(Slide courtesy of D.S.)
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Dust attenuation correctionSchiminovich, Ilbert,
Arnouts et al. (2005)
Using UV slope ? AFUV f(?)
FWHM(?)1.4 ?(?)0.4
(Meurer et al.,1999Kong et al., 2004)
Full sample ? consistent with - local FUV
sample (Treyer et al., 2005) - high-z sample
(Adelberger, 2000)
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Uncorrected SFR vs. Z
Schiminovich, Ilbert, Arnouts et al. (2005)
Conv. LFUV to SFR (Kennicutt, 1998) No
dependence of dust attenuation AFUV with SFRuncor
NUV lt24.5
NUV lt26 (UDIS)
L(z)
As a consequence
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Corrected SFR vs. Z
Schiminovich, Ilbert, Arnouts et al. (2005)
Conv. LFUV to SFR (Kennicutt, 1998)
AFUV (Meurer et al., 1999)
NUV24.5 AFUV 4.0 2.5 1.5
0.5 0.
Paucity of low AFUV galaxies with high SFRcor
? - Large scatter in the measured AFUV ? -
Dust attenuation law?
M99 relation may overestimate AFUV for
star-forming galaxies
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Evolution of the SFR Density uncorrected and
dust-corrected (hatched region)
Uncorrected SFRD
(1z)2.5
0ltzlt1.5 ?2.5 1.2ltzlt3 ?0.5
Corrected SFRD
Meas ltAFUVgt1.8 Min AFUV1.0 (local UV sample
Buat et al. 2005)
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Photometric Reshifts in F02 field works by
Ilbert , Arnouts, Budavari et al
Photometry used VVDS
(U)BVRI(JK) CFHTLS ugriz SWIRE 3.6 4.5?m
VVDS (U)BVRI (JK)
GALEX
Classification in Galaxy/Star/QSO
FUV LF with photo-z for a large sample
Z photometric Area 0.65 deg2
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Photometric Reshifts of UV galaxies in F02 field
Secure Zspec 949
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Photometric Reshifts of UV galaxies in F02 field
All Zspec 1127
VVDS (U)BVRI (JK)
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Color-color checks vs classification
(NUV-B) vs (B-I)
VVDS (U)BVRI (JK)
Star/galaxy separation Galaxies below the line
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Color-color checks vs classification
VVDS (U)BVRI (JK)
(FUV-NUV) vs (B-I)
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Color-color checks vs classification
(B-I) vs (3.6-4.5)
VVDS (U)BVRI (JK)
Same QSOs and Stars regions for spec. and phot.
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Galaxy Redshift distribution
VVDS (U)BVRI (JK)
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FUV Luminosity Function with 6000 Z-photo
At z1 no constraint on slope Consistent with
?-1.6
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FUV Luminosity Function Zspec vs Zphot

• Consistent with LF(spec)
• Smaller errorbars
• At 0.2ltzlt0.4
• constraint on M

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FUV Luminosity Function Zspec vs Zphot
No evolution in ? 0ltzlt0.8
Fixed ?
Consistent M(z) evolution
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Galaxy Type classification with Zspec
(Arnouts, Schiminovich, Ilbert et al., 2005)
Kinney et al, 1996

• - Small number of galaxies
• redder than Sb
• Degeneracy between
• old syst. and dusty SB

Poggianti et al 1997
(NUV-R) correlated with SFRcurrent/ ltSFRgtpast
(Salim et al. 2005) Galaxy SF history (B-I)
correlates with (NUV-R) (B-I) as a crude proxy
for galaxy type
Apply to the Zphot sample
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Galaxy Type classification with Zphot
Type fraction vs Z
(FUVlt22, zlt0.2)
Increase of the unobscured SB class from z0 to 1
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Galaxy Type LF with Zphot
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Galaxy Type LF with Zphot
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Galaxy Type LF with Zphot
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Galaxy Type LF with Zphot
Similar evolution for the two reddest
classes Stronger evolution of the SB class wrt
red ones
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Galaxy Type LF with Zphot
?(z)constant per type 2 Red classes -0.9lt ?
lt-1.2 SB class -1.5lt ? lt-1.8
Modest luminosity evolution of SB class wrt
reddest classes
Number density evolution of the SB class
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• Conclusion
• GALEX-VVDS PILOT STUDY
• Global evolution of the FUV light of galaxies in
  0ltzlt1.5
• 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 0.5ltzlt1 (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)

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• Conclusion
• GALEX-VVDS PILOT STUDY
• Global evolution of the FUV light of galaxies in
  0ltzlt1.5
• 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 0.5ltzlt1 (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)