GOODS-Herschel: an IR main sequence for star forming galaxies! from the Main Sequence to starbursts and obscured AGNs

Transcription

1 GOODS-Herschel: an IR main sequence for star forming galaxies! from the Main Sequence to starbursts and obscured AGNs David Elbaz, CEA Saclay Mark Dickinson, Emanuele Daddi Ho Seong Hwang, Georgios Magdis, Maurilio Pannella Tanio Diaz-Santos, Benjamin Magnelli & GOODS Herschel team

2 GOODS-Herschel: an IR main sequence for star forming galaxies! from the Main Sequence to starbursts and obscured AGNs There are many reasons to believe that the physics of galaxy/star formation is a complex process involving turbulence, multiphase physics, magnetic fields, shocks... mergers, environment effects, positive/negative feedback/agn % of stars formed ~ % Universe age! ~ 25% of present-day stars Le Borgne, Elbaz, Ocvirk, Pichon 10

3 GOODS-Herschel: an IR main sequence for star forming galaxies! from the Main Sequence to starbursts and obscured AGNs There are many reasons to believe that the physics of galaxy/star formation is a complex process involving turbulence, multiphase physics, magnetic fields, shocks... mergers, environment effects, positive/negative feedback/agn Morphological studies have globally failed. Merger rate? Progenitors of Sp/E?? z=0 z=1.5 (-10 Gyr)

4 Scaling laws for early-types... Early-types follow some simple scaling laws (fundamental plane) => common history of star formation Star formation appears to have taken place in short timescales in these systems Most present-day stars are locked in such systems. SNIa: O-> Si 28 -> Ni 56 -> Co 56 -> Fe 56 Thomas +05

5 Scaling laws for late-types... Schmidt-Kennicutt relation : projected SFR surface density ~ gas surface density! puzzling that it extrapolates to the population of mergers such as (U)LIRGs Why is the SK slope >1? Slope 1.4 => SF efficiency larger in (U)LIRGs Schmidt-Kennicutt relation Kennicutt 1998 >3x10 4 cm -3 for HCN >500 cm -3 CO (H 2 ) Gao & Solomon (2004)

6 Scaling laws for late-types... a unique SK law or 2 modes of SF? Daddi +10, Genzel +10! CO =M(H 2 )/L CO! CO =0.8 for mergers/ulirgs! CO =4.5 for mergers/ulirgs!=4.5 for normal Sp!=4.5 for normal Sp Conversion factor: same! CO for all galaxies in Kennicutt (1998)! CO / 6 for (U)LIRGs (Downes & Solomon 98, Solomon & Vanden Bout 05) Bouché +07 => slope= 1.7! 1.4 Steeper slope or 2 modes of star formation?

7 Scaling laws for late-types... a unique SK law or 2 modes of SF? Large % of massive (K-sel.) z= galaxies (BzK) harbour high SFR (few M " yr -1 )! high duty cycle ~40%, SF lasting ~0.5 1 Gyr! large gas reservoirs? If long lasting SF! not merging powered ULIRGs!! gas properties, conversion factors? High-z CO SEDs : warm gas, brightest CO fluxes are transitions J 5 to 7 ~ M82 nucleus. High gas densities, merger (?)! require knowledge of several transitions to determine the correction factor...! CO =M gas /L CO = 4.6 M " (K km s -1 pc 2 ) -1 for Milky-Way (Solomon & Barrett 1991)! CO =M gas /L CO = 0.8 M " (K km s -1 pc 2 ) -1 for ULIRGs (Downes & Solomon 1998) Weiss et al 2007 If! CO is spiral-like in massive z=1.5 galaxies => extremely gas rich 1) gas mass ~1-2x10 11 M " of H 2 2) gas fractions ~60% or more Dannerbauer, Daddi +09, +11 IRAM PdBI B-conf (1.3 mm, GHz) IRAM PdBI D-conf (0.87 mm, GHz) VLA Bconf (2.6 mm, GHz)

8 Scaling laws for late-types... a unique SK law or 2 modes of SF? Ivison +11 Daddi, Elbaz +10 Normal galaxies detected in CO (Daddi +08,10, Dannerbauer +09, Aravena +10; Tacconi +10; Genzel +10; Salmi +11) Dannerbauer +11

9 IRAS : 57 cm Discovery of luminous IR galaxies, >90% of light in IR Dominate the bright-end of the luminosity function Mostly major mergers ISO : 60 cm Space density of LIRGs x70 at z~1 They dominate the SFR density at z>0.7 Extrapolation to far IR! bulk of the IR background / LIRGs Spitzer : 85 cm Herschel: 350 cm At z=0! ~2

10 IRAS : 57 cm ISO : 60 cm Discovery of luminous IR galaxies, >90% of light in IR Dominate the bright-end of the luminosity function Mostly major mergers Space density of LIRGs x70 at z~1 They dominate the SFR density at z>0.7 Extrapolation to far IR! bulk of the IR background / LIRGs Spitzer : 85 cm v Stacking in far IR! resolve peak IR bkg Increasing density LIRGs/ULIRGs up to z~2 Large Sp fraction among z~1 LIRGs signature of Compton Thick Compilation by Hopkins 2004" total! L IR <10 11 L "! L IR >10 11 L "! ULIRGs! Le Floc'h +05!

11 problems with extrapolations from both sides of the peak IR SED Papovich +07, Daddi +07 obscured AGNs Compton thin unobscured AGNs Compton Thick AGNs MIR-excess & stacking (Daddi +07, Papovich +07, Magnelli +09, Murphy +09, Fadda +10, Yan +05) : larger PAH emission or AGN? AGN contribution to MIR: CXB unresolved (Gilli +07,...) SMGs! different IR SEDs: colder Tdust + larger PAH EW (Pope +08,...) Distant galaxies are less metal rich!less dust,! PAH? (Madden +05, Engelbracht +05)

12 !"#$%&'()*'+%#,"-.'/'0*'(12#' >200M! yr -1 >20M! yr -1 >1500M! yr -1 CE01 + counts Magnelli, Elbaz + 10 Le Borgne, Elbaz +09 cosmic SFR density peaks at z~1 or 2? do ULIRGs dominate the CSFR at z~2? until now, bolometric luminosity extrapolated from mid-ir or sub-mm! GOODS - Herschel

13 Herschel 57% of the Herschel routine mission science time is dedicated to Key Programmes ( hours) : 52% of Guaranteed Time KP ( hours)= 93% of all GT 48% of Open Time KP ( hours)= 40% of all OT 22% of all KP time for extragalactic surveys : 26% of all GT KP (1555h, 62% of extragal.surveys) : HERMES (SPIRE GT, 900h) coordinated by S.Oliver & J.Bock PEP (PACS GT, 654.9h) coordinated by D.Lutz 18% of all OT KP (962.6h), 62% of extragal.surveys : ATLAS (PI S.Eales, 600h) GOODS-Herschel (PI D.Elbaz, 362.6h)

14 GOODS-Herschel (Herschel Open Time Key Program)" The Great Observatories Origins Deep Survey : far infrared imaging with Herschel Collaborators (60): Fr, US, G, UK, Gr, It, Can, ESO, ESA hours (100µm & 160µm PACS + 31h SPIRE) 1. to resolve most of the cosmic SFR density up to z 4, by detecting 2000 galaxies in the unexplored regimes of normal galaxies up to z 1, LIRGs up to z 2, ULIRGs to z~4 2. to bridge IR and UV selected galaxies down to the level where both SFR agree up to z 1.5 and potentially up to z 4 as discussed below. 3. to identify and study the buried Compton Thick AGNs responsible for the still unresolved 30% fraction of the cosmic X-ray background (CXB), which peaks at 30 kev.

15 X UV U B V I Z J H K 3.6µm 4.5µm 5.8µm 8µm IRS16 MIPS24 radio 2x10-16 erg/s/cm 2 ~28AB 22AB µjy µjy µjy 1 µjy Herschel extragalactic surveys" GOODS-Herschel OT KP Wilson 07 ESO-report

16 COBE (NASA) GOODS-North 100/160/250 µm GOODS-South 24/100/160µm 240 µm (COBE/DIRBE, NASA)

17 3442(567-#&+78'9-":7#',+7';8<$=,7'>79,+#'-7=&+=:87':.'67-#&+78'?' MIR remains crucial 1468 galaxies 70% complete in spec z ~30% in phot z

18 Deep far infrared images with a 3.5 m telescope:! challenging the confusion limit

19 *",$%&!"#$%& '($%& )*$%& +#*$%& 6.5' 7.5'

20 The power of multi-wavelength imaging against confusion -**$%&!-*$%&'-*$%& +#*$%&+**$%&'($%&!"#$%&*",$%& 7.5' x 6.5' zoom on the GOODS-North field (10' x 15') HGIN' LGI'=-&$%M'

21 HST Spitzer Herschel PACS & SPIRE VLA F#$ 1.5' boxes z = L IR = 2.6 x L " from far-ir vs L IR = 3.5 x L " "from 24um" FWHM=6.7" 11" 18.1" 24.9" 36.9" 160µm 250µm 350µm 500µm 160µm 70µm 100µm 350µm 100µm 70µm 24µm 24µm modified blackbody, "=1.5 modified! Tdust blackbody, "=1.5! Tdust Hwang +10 %(µm)$

22 !"#$"%&'&()#*'$"#+(,-(".(#%/&#01'&#%/&2$"3#3'4'5$(0# starbursts Stellar mass

23 MIR-FIR correlation (Chary & Elbaz 01, Elbaz et al 02) IR vs ISOCAM 15 µm IR vs IRAS 12 µm IR vs ISOCAM 6.75 µm Chary & Elbaz 01 David Elbaz Latest news from deep infrared surveys 23

24 Before Herschel total IR luminosities were extrapolated from the mid-ir & submm L(IR) vs L(15 µm) 15 µm vs IR L(IR) vs L(12 µm) L(IR) vs L(6.75 µm) K correction

25 The mid-ir excess problem... SED evolution/agn/k-correction?... mir and far IR consistent with local SEDs (Chary & Elbaz 01) up to z~1.5 (blue, green dots) at z>1.5: "mid-ir excess" (Daddi +07, Papovich +07) (orange, red dots) 24µm Elbaz, Hwang +10, 11 GOODS-Herschel (Elbaz, Hwang +11)

26 The mid-ir excess problem... SED evolution/agn/k-correction?...

27 0*'$=%M'#7O;7M&7'?'F'$">7#'"P'#,=-'P"-$=<"M'Q'

28 6&$3$"#/%#17(#18/#01'&#%/&2'9/"#2/)(0#:# 17(#&/4(#/%#01'&#%/&2'9/"#./2;'.1"(00<<<#2(&3(&0<<<'

29 0*'$=%M'#7O;7M&7'?',+7'-"87'"P'()'&"$9=&,M7##'

30 0*'$=%M'#7O;7M&7'?',+7'-"87'"P'()'&"$9=&,M7##'

31 0*'$=%M'#7O;7M&7'?',+7'-"87'"P'()'&"$9=&,M7##'

32 0*'$=%M'#7O;7M&7'?',+7'-"87'"P'()'&"$9=&,M7##'

33 6&$3$"#/%#17(#18/#01'&#%/&2'9/"#2/)(0#:# 17(#&/4(#/%#01'&=-&010<<<'

34 Definition of a "starburst" t(gas consumption)= Mgas / SFR = 1 / SFE (SF efficiency) Definition #1: t(gas consumption) << t(hubble) => starburst The Antennae: (LIRG) L IR =1.1x10 11 L!! SFR= 19 M! yr -1 M(H 2 )=3.9x10 9 M! Molecular gas exhausted in 200 Myr The Super-Antennae: (ULIRG) L IR =1.1x10 12 L!! SFR= 190 M! yr -1 M(H 2 )=3x10 10 M! Molecular gas exhausted in 160 Myr

35 Dusty starbursts at z~0 Definition #2 of a starburst: exceptional event b > 2-3 where : b=sfr/<sfr>= birthrate parameter Good proxy = specific SFR (ssfr) assuming same age: ssfr= SFR/M* = SFR/<SFR> x 1/age SFR/M* ~ 0.06 Gyr -1 (MW)! & # 20 Gyr (time to x2 M*) x 10 = 0.5 Gyr -1 (M82)! & # 2 Gyr x 200 = 10 Gyr -1 (Arp220)! & # 0.1 Gyr SDSS data from Brinchmann et al. 04 Elbaz et al. 07

36 The SFR stellar mass correlation: Arp220 M82 MW

37 The SFR stellar mass correlation as a function of redshift Arp220 M82 MW

38 The SFR stellar mass correlation as a function of redshift Arp220 M82 MW At z~1, LIRGs are no more outlyiers All M * >5x10 10 M! are LIRGs or «dead»!

39 The SFR stellar mass correlation as a function of redshift Arp220 M82 MW BzK galaxies (Daddi et al. 2005, 2007): 40% of M * "5x10 10 z= are ULIRGs 'z= 2 Gyr! long duty cycle (> 400 Myr)

40 L 8

41 ()'%M'>%#,=M,'7R&7##'0*J'T=8=R%7#'%#'$"-7'&"$9=&,'%M'-7#,5P-=$7'VW' HST 2700Å HST 2700Å HST 2700Å

42 1/8'&)#'#-"$?(&0'4#>B#+CD#%/&#*+#'")#+E#3'4'5$(0'

43 X-","5,.9%&=8'0*'(12'"P'Y=%M'(7O;7M&7'=M>'(,=-:;-#,'T=8=R%7#' Main Sequence Starburst : ssfr > 2 x ssfr(ms ) Main Sequence : broad far-ir bump K, strong PAH features, ISM= 38 %, SF= 62 % SED Starbursts : peaked far-ir bump K, weak PAH features, ISM= 0 %, SF= 100 % SED Model fit: 2 components, "diffuse ISM" and "star forming region" Range of dust temperatures but ISM range wide T dust (ISM)~ 18 K, T dust (SF)~ 50 K

44 Main Sequence Starburst Galliano +08

45 CE01 library of template IR SEDs

46 Unique IR SED for all galaxies: main sequence

47 !&(#)$01'"1#3'4'5$(0#./4)(&#17'"#4/.'4#/"(0#:'

48 Hwang, Elbaz +10 2"'S7'#77'=M.'7Z%>7M&7'P"-'=M'7Z"8;<"M'"P'[>;#,'Q '

49 2"'S7'#77'=M.'7Z%>7M&7'P"-'=M'7Z"8;<"M'"P'[>;#,'Q ' FIR properties derived by the same method for all samples!s 4)*3' IRAC bump selected galaxies: Magdis +10 Fill the gap, no Tdust selection # SMGs prior to Herschel were biased # large dispersion in Tdust ]"&=8' V]0*3#' Y=TM788%\'AD' Hwang, Elbaz +10 Magnelli +10, Magdis, Elbaz +10, Chapman +10

50 IRAC peakers are missed by smm surveys Y=T>%#'\AD'

51 F/8'&)0#'"#'..-&'1(#)(1(&2$"'9/"# /%#17(#=/4/2(1&$.#/-1;-1#/%#3'4'5$(0A# G'?(#8(#2$00()#0/2(#/=0.-&()#!HI0#:' obscured AGNs Compton thin unobscured AGNs Compton Thick AGNs

52 (7=-&+%MT'P"-':;-%7>'^3_#'S%,+'0*J'6+7//#8+6'.-/9'#8,-7"-#:%+##' X-ray AGNs Power-law AGNs high & low IR8 : ~10%! ~20% high IR8 : 15%! 19% low IR8 : 33%! 70%

53 (7=-&+%MT'P"-':;-%7>'^3_#'S%,+'0*J'6+7//#8+6'.-/9'#8,-7"-#:%+##'

54 F7(#*'$"#+(,-(".(#/%#01'&#%/&2$"3#3'4'5$(0# Distant (U)LIRGs are long-lasting events (few Gyrs!) contrary to local ones (200 Myr) Mostly "normal" galaxies, i.e. follow Main Sequence in Specific SFR, SF efficiency & L IR /L 8 IR8= L IR /L 8 and SFR M* confirm existence of a main sequence mode of SF : disk/extended Starbursts= compact SF with excess IR8, not directly related to L IR or SFR Good representation of IR SED for MS and SB galaxies! bolometric correction! LIRG = SB at z~0 but MS gal at z~1 if M*>5x10 10 M " (ULIRG@z=2, M*>2x10 11 M " ) Low far-ir/8um from dusty AGNs can be hidden by concommittant starbursts boosting IR8.! after de-boosting IR8 from "starburstiness" : candidate population of obscured AGNs! missing fraction of X-ray background?... 3 Main Sequences of SF galaxies! Fundamental tryptic ~ fundamental plane for ellipticals! Main Sequence galaxies dominate the cosmic SFR density at all redshifts!! The fall in cosmic SFR driven by the decrease in gas mass Starbursts vs Main Sequence galaxies = progenitors of E's and Sp's?

55 [+7'P;M>=$7M,=8',-.9<&'"P'#,=-'P"-$%MT'T=8=R%7#' SFR L8 SFR M* SFR Mgas SFR L8 SFR M* SFR Mgas

56 J(&0;(.9?(0' ALMA and emerlin to study compactness of SF regions SINFONI to study dynamical stage of high IR8 galaxies IR SED - compactness relation = powerful technique for JWST./012&%324325' Hernquist, Springel, di Matteo, Hopkins et al Dynamical Instabilities: Bournaud, Elmegreen Cold flows: minor mergers & steady accretion Dekel +09 HORIZON simulation Ocvirk, Pichon, Teyssier 08