yanchun liang (naoc, china) 2005-08, lijiang

The Luminosity-Metallicityand Mass-Metallicity Relations

of 0.4<z<1 Luminous Infrared Galaxies :

Yanchun Liang (NAOC, China)2005-08, Lijiang

---implication on the mass and metal assembly of galaxies

Collaboration with Francois Hammer, Hector Flores, Francois Assemat at Paris-Meudon Observatory;David Elbaz, Delphine Marcillac at Saclay-Service d’Astrophysique;Nicolas Gruel at Florid University;Xianzhong Zheng at MPIE;Licai Deng at NAOC;Catherine J. Cesarsky at ESO.

How much star formation was hidden by dust over the history of the universe ?

(2) COBE (DIRBE) detected a diffuse background at > 140 m

(3) Surveys at 15,90,170,450,850m (ISO, SCUBA) strong evolution

240 m

(1) (1) IRASIRAS ((z<0.3z<0.3)): : detected tens of thousandsdetected tens of thousandsof galaxies with the FIR radiation luminosities of galaxies with the FIR radiation luminosities

From 10From 1066LLsunsun to ~10 to ~101313LLsunsun, , but only but only ~2%~2% of of the local bolometric luminosity densitythe local bolometric luminosity densityis due to the is due to the luminous IR galaxiesluminous IR galaxies ((Soifer et al. 1987, ARA&A, 25, 187; Soifer et al. 1987, ARA&A, 25, 187; Sanders & Mirabel 1996, ARA&A, 34, 749Sanders & Mirabel 1996, ARA&A, 34, 749)

(Elbaz et al. 2002, A&A 384, 848)(Elbaz et al. 2002, A&A 384, 848)

ISOCAM 15 m MIR source counts

(1)(1) ISO 15 ISO 15 m source source counts show strong counts show strong evolutionevolution

(2)(2) The comoving density The comoving density of infrared light due to of infrared light due to the luminous galaxies the luminous galaxies (L(LIRIR>10>101111LLsunsun) was more ) was more

than than 4040 times larger times larger at at z~1 than today z~1 than today

(3)(3) The main responsibility: The main responsibility:

the luminous Infrared the luminous Infrared starburst galaxies seen starburst galaxies seen by by ISO at z>0.4ISO at z>0.4, , SFRs > 50 MSFRs > 50 Msunsunyryr-1-1

(Elbaz et al. 1999, A&A Lett., 351, L37)(Elbaz et al. 1999, A&A Lett., 351, L37)(Elbaz et al. 2002, A&A 384, 848; Elbaz & (Elbaz et al. 2002, A&A 384, 848; Elbaz & Cesarsky, 2003, Science, 300, 270; Flores et al. 1999, ApJ 517, 148) Flores et al. 1999, ApJ 517, 148)

(4) Most of ISOCAM ((4) Most of ISOCAM (>75%>75%)galaxies are )galaxies are StarburstsStarbursts, AGN only contribute ~20% , AGN only contribute ~20% (Elbaz et al. 2002 A&A 384 848; Fadda et al. 2002, A&A, 383, 838; Flores et al. 1999;(Elbaz et al. 2002 A&A 384 848; Fadda et al. 2002, A&A, 383, 838; Flores et al. 1999;

Franceschini et al. 2003, A&A, 403, 501; Liang et al. 2003b, A&A, submitted)Franceschini et al. 2003, A&A, 403, 501; Liang et al. 2003b, A&A, submitted)

(Le Flo’ch et al. 2005, ApJ, astro-ph/0506462 )

Evolution of the comoving IR energy density up to z=1 (green-filled region) and the respective contributions from low luminosity galaxies (i.e., LIR<1011Lsun, blue-filled area), ``infrared luminous'' sources (i.e., LIR>1011Lsun, orange-filled region) and ULIRGs (i.e., LIR>1012Lsun, red-filled region).

The solid line evolves as (1+z)3.9 and represents the best fit of the total IR luminosity density at 0<z<1. Estimates are translated into an ``IR-equivalent SFR'‘ density given on the right vertical axis, where an absolute additional uncertainty of $\sim$\,0.3\,dex should be added to reflect the dispersion in the conversion between luminosities and SFR.

The Spitzer view on the history of dusty star formation at 0<z<1

Spectroscopy (VLT/FORS2)follow-up

for a large sample of ISOCAM-selected sources

(Extinction, Metallicities,L-Z, Mass-Z)

(Liang et al. 2004, A&A, 423, 867)(Liang et al. 2004, A&A, 423, 867)

1. The ISO-selected sample : 105 in 3 fields CFRS 3h, UDSR (Ultra-Deep-Survey-Rosat, Marano field), UDSF (Ultra-Deep-Survey-Firback, Marano field) (Flores et al. 2004, Elbaz et al. 2004, in preparation )

2. The Optical Observations using using VLT/FORS2 VLT/FORS2 with R600 and I600with R600 and I600

spectrograph with a resolution of spectrograph with a resolution of 5 5 ÅÅ, R=1200, R=12005000 - 9000 5000 - 9000 Å, Å, slit width slit width 1.21.2"" slit length 10slit length 10""

Log(LLog(LIRIR/L/Lsunsun))medmed==11.26 11.26 ( LIRGs with Log(L ( LIRGs with Log(LIRIR/L/Lsunsun)>11) )>11)

3. Redshift identifation

4. Infrared luminosities

9292 z zmedianmedian==0.5870.587 (64 with z>0.4) (64 with z>0.4)

5. Emission Line Galaxies (ELG) 85% EL galaxies in the ISO-detected objects85% EL galaxies in the ISO-detected objects , 81%81% EL galaxies in the total EL galaxies in the total

IR luminosity

Similar to Similar to Veilleux et al.1995,Veilleux et al.1995,

Kim et al. 1995:Kim et al. 1995:11.34 for BGSs11.34 for BGSs11.38 for WGSs11.38 for WGSs

HH00=70 km/s/Mpc=70 km/s/Mpc

MM=0.3, =0.3, LL=0.7=0.7

Log(LLog(LIRIR/Lsun)/Lsun)medmed

=11.26=11.26

9 10 11 12 13

Deblending…

Examples in Examples in UDSFUDSF

z=0.7094z=0.7094 Log(LLog(LIRIR/Lsun)=11.38/Lsun)=11.38

Estimate dust extinction

1) Using H/Hratio : A A VV(Balmer)(Balmer)2) Using energy balance between Hbetra and IR : AA V V(IR)(IR)

Stellar absorption correctionStellar absorption correctionJacoby et al. (1984)Jacoby et al. (1984)

Diagnostic diagram: Starbursts

Most of them (Most of them (>77%>77%) are HII-region-like galaxies) are HII-region-like galaxiesConsistent with other fields:>70% of ISOCAM/15Consistent with other fields:>70% of ISOCAM/15m galaxies, “starbursts” m galaxies, “starbursts”

Oxygen abundances in ISM

12+log(O/H) = 8.35 – 8.93, median 8.6712+log(O/H) = 8.35 – 8.93, median 8.67

RR2323 and calibration from Kobulnicky et al. 1999 and calibration from Kobulnicky et al. 1999

Luminosity-Metallicity relation (L-Z)Luminosity-Metallicity relation (L-Z)& Mass-Metallicity relation (Mass-Z)& Mass-Metallicity relation (Mass-Z)

L-Z relation: z> 0.4 LIRGs are metal deficient

03.0035

! z> 0.4 LIRGs are 0.3 dex metal-poor from local disks

(at a constant MB): ~ 50%

(12+log(O/H) = 8.35 – 8.93, (12+log(O/H) = 8.35 – 8.93, median 8.67)median 8.67)

! They can reach local disks locus assuming an infall time of ~ 1 Gyr

(PEGASE2, Fioc and Rocca-Volmerange, 1999,astro-ph/9912179: Mtot=1011Msun ,

also see Kobulnicky et al. 2003, ApJ, 599, 1006)

(Liang et al. 2004, A&A, 423, 867)(Liang et al. 2004, A&A, 423, 867)

Are massive spirals already formed at z~ 1 ?

! Lilly et al (1998) large disk sample (rdisk > 4 h50-1 kpc) at 0.5 < z < 1:

32 (+/-13)% of them are LIRGs

! Connection between LIRGs and disks (z>0.4) (HST morphologies and

color maps) : 40% of LIRGs are large disks (Zheng et al, 2004, A&A)

! LIRGs have large stellar masses: 1.4 1010MO <MK < 2.9 1011MO

(see also Franceschini et al. 2003, A&A, 403, 501)

! LIRGs have high SFRs: >50 Msunyr-1 , TSF(M/SFR)=0.1-1 Gyr

Tim

e

(Gyr)

(Mass double time scale: 0.1-1 Gyr)

(Hammer et al. 2005,A&A,430,115)

The Mass-Metallicity relation of 0.4<z<1 galaxies

30% to 50% of the mass locked in stars in present day galaxies actually condensed into stars at z<1 (Dickinson et al. 2003; Pozzetti et al. 2003; Drory et al. 2004; Bell 2004)

Which kinds of galaxies are mainly responsible for such star formation fraction?

The near-IR K-band luminosity is more directly related to the stellar mass of galaxies since it is less affected by star formation and by dust (Charlot 1998; Bell & de Jong 2000):

We compare the MK-metallicity (mass-Z) relations of these intermediate-z galaxies with those of local star-forming galaxies.

(Liang, Hammer, Flores 2005, A&A, submitted)

The 3 local sample galaxies to compare:

NFGS (Nearby Field Galaxy Survey) by Jansen et al. 2000a,b

KISS ( Salzer et al. 2005)SDSS (Tremondi et al. 2004; Bell et al.

2003)

NFGS

from Jansen et al. 2000a,b

Such z> 0.4 galaxies are 0.3 dex more metal-poor from local disks (at a given MK): ~ 50%

KISS

from Salzer et al. 2005

SDSS

Tremonti et al. 2004, Bell et al. 2003;

The 7 galaxiesat z~2.3 from Shapley et al. 2004

Summary

Spectroscopy follow-up for a ISO-selected sample galaxies with 0.4<z<1

We study their metallicities on the basic of VLT/ FORS2

spectra, the median oxygen abundance of them is 12+log(O/H)~8.67: ~0.3dex more metal deficient than the local star forming galaxies at the given magnitude or stellar mass

By comparing with the local galaxies (e.g. NFGS, KISS, SDSS) and the high-z (z~2.3) galaxies, we can get a basic understanding on the assembly of the metals of galaxies: ~ 50% of metals of these intermediate-z galaxies was formed since z ~ 1