Dusty star-forming galaxies at high redshift (part 7)

Transcription

1 Dusty star-forming galaxies at high redshift (part 7) Flow of story 4 Redshifts and Spectral Energy Distributions of Infrared- Luminous Galaxies 5 Physical Characterization 1

2 Physical Characterization DSFG s physical characterization redshift luminosity characterization DSFG s intense IR luminosity physical setup cosmological framework galaxy formation process AGN starburst regions gas stars kinematic history dust and gas masses physical extent of galaxies interactions with other galaxies Physical Characterization DSFG s physical characterization physical characterization selection function molecular gas radio ~ X-ray characterization star formation history stellar masses kinematics dynamical time stellar IMF physical size dust characterization AGN content 2

3 Flow of story Star Formation History & Dynamical Time Dust Characterization Stellar Masses Star Formation History & Dynamical Time dynamical time high-z galaxies timescale of the burst small sample + local ULIRG IRAS sample depletion timescale τ depl = molecular gas mass / SFR Solomon and Sage (1998) local merger ULIRG τ depl or L FIR / L CO merger (interaction) -> τ depl down or L FIR / L CO up 3

4 Star Formation History & Dynamical Time dynamical time high-z CO Bothwell et al. (2013a) 850 μm-selected source Carilli and Walter (2013) high-z molecular gas survey all CO survey τ depl = 100~200 Myr (SMGs) v.s. ~1Gyr (normal galaxies) local τ depl <- gas fraction high-z Flow of story Star Formation History & Dynamical Time Dust Characterization Stellar Masses 4

5 Dust Characterization λ peak L IR realation Fig. 25 luminosity-dust temperature relation Dust Characterization λ peak L IR realation high-z dust temperature Herschel SMGs FIR SED measurement R-J select warmer dust bias Herschel-SPIRE z~2 peak high-z colder dust selection bias extended dust distributions 5

6 Dust Characterization dust mass FIR photometry dust mass R-J black body estimator 850 μm dust mass μm 850 μm colder, more massive dusty galaxies 1 M dust S ν T dust (Eq. 12) Herschel-selected galaxies lower redshift Dust Characterization dust mass Ivison et al. (2011) high-z 850 μm-selected SMGs CO(1-0) observation SMGs local dust-to-gas ratio L CO /L 850 local consistent ~ < z < 2 modest star former by Herschel dust mass stellar mass (or ssfr) gas-to-dust ratio metallicity on/off star forming main sequence gas fractions 6

7 Flow of story Star Formation History & Dynamical Time Dust Characterization Stellar Masses Stellar Masses determining stellar mass high-z stellar mass 1 stellar mass high-z dusty galaxies 7

8 Stellar Masses Star Formation History (SFH) SFH exponentially declining constant single burst multiple-component Dunlop (2011) stellar mass : multiple-component > single burst UV emission consistent young star Stellar Masses Star Formation History (SFH) continuous SFH SFR <- UV flux starburst duration <- optical/nir emission multi-component SFH single + continuous burst UV emission driven continuous SFH optical emission single SFH 8

9 Stellar Masses Star Formation History (SFH) burst massive galaxies Thomas et al. (2005), McDermid et al. (2012), Pacifici et al. (2013) stellar population mass Davé et al. (2012) lognormal SFH fit halo mass calibrate lognormal SFH second late burst component Stellar Masses Star Population Synthesis (SPS) model Conroy (2013) review paper Hainline et al. (2011) Bruzual & Charlot (2003) model Maraston (2005) model dust mass ~50% 9

10 Stellar Masses stellar Initial Mass Function (IMF) local high-z massive stars & low-mass stars IMF bottom-heavy Chabrier (2003) IMF or Salpeter (1955) IMF stellar mass factor ~1.8 ( SFR ) Stellar Masses many works on stellar mass Borys et al. (2005) submm galaxy population high-z DSFGs stellar mass instantaneous burst SFH & constant SFH Miller-Scalo IMF (Miller & Scalo, 1979) log M = [11.14, 12.15], M = MK 3.3 /LKM, LKM ~ 3.2 median M = M AGN contamination 10

11 Stellar Masses many works on stellar mass Dye et al. (2008) Bruzual & Charlot (2003) photometric data stellar mass Borys et al. (2005) comparable 8 bands Stellar Masses many works on stellar mass Hainline et al. (2011) ~70 SMGs 10 % SED AGN AGN heating stellar emission rest-frame K-band rest-frame H-band M = M 11

12 Stellar Masses many works on stellar mass Minchalowski et al. (2010) Hainline et al. (2011) 76 SMGs stellar mass M = M IMF factor 3 (Hainline et al. 2011) AGN contamination IMF, SPS model, SFH Stellar Masses other approaches high-z SMGs IMF factor 2~3 CO dynamical measurement with assumed dark halo remaining stellar mass HI SMGs dynamical state 12

13 Stellar Masses other approaches abundance matching methodology M halo mass a priori massive galaxies massive halo least massive galaxies least massive halo Behroozi et al. (2013) M halo = M, z = 2 -> M M Hickox et al. (2012) halo mass Hayward (2013) stellar mass Stellar Masses connection between DSFGs high-z DSFGs stellar mass Berta et al. (2007) & Lonsdale et al. (2009) Spitzer-selected ULIRG stellar mass Bussmann et al. (2012) bump-like or powerlaw-like color select bump-like -> stellar spectra opacity feature powerlaw-like -> AGN contribution or dust opacity DOGs 2 traditional SMGs massive 13

14 Stellar Masses importance of stellar mass constraint DSFGs high-z population redshift galaxy main sequence NIR IFU luminosity AGN CO [CII] dynamical mass estimate high-z DSFGs stellar mass Flow of story Stellar IMF Rest-frame Ultraviolet & Optical Spectral Characterization AGN Content 14

15 Stellar IMF IMF (initial mass function) physical condition IMF cf. Bastian et al. (2010) log-normal distribution + steeper slopes at low/high mass bottom-light : low mass M peak (or M ) bottom-heavy : low mass M peak (or M ) top-heavy : low mass slope Stellar IMF IMF shape at high-z Baugh et al. (2005) starburst galaxies Kennicutt (1983) IMF more flat IMF SCUBA counts match colder dust top-heavy -> more UV photons, higher yield of dust Hayward et al. (2013b) local IMF match 15

16 Stellar IMF IMF shape at high-z Tacconi et al. (2008) CO H 2 conversion factor, stellar mass, IMF (z~2) IMF high mass excess Kroupa IMF M/L high-j CO transition low-j integrated SMG SFH local baryon density (Blain et al., 1999) Stellar IMF IMF shape at high-z integrated SFH evolution of SMF high-z bottom-light or top-heavy IMF IMF SFR van Dokkum (2008) z~1 early type galaxies color evolution M/L bottomlight IMF Salpeter IMF consistent (van Dokkum & Conroy, 2012) 16

17 Stellar IMF IMF shape at high-z Davé (2008) z~2 main sequence galaxies SFR simulation match bottom-light IMF z~2 inferred SFR Stellar IMF IMF shape at low-z high SFR surface density bottom-light/top-heavy Rieke et al. (1993) & Förster Schreiber et al. (2003) Kroupa IMF factor 2-6 turnover mass Fardal et al. (2007) K-band luminosity density, CBR, SFRD intermediate mass excess Nayakshin & Sunyaev (2005) & Stolte et al. (2005) Milky Way top-heavy 17

18 Stellar IMF IMF shape at low-z dynamical method SPS model bottom-heavy gravity sensitive absorption line (FeH, CaII, NaI) K/M dwarfs K/M giants z~0 early type galaxies bottom-heavy kinematics M/L M/L bottom-light or bottom-heavy bottom-light -> low mass star bottom-heavy -> stellar remnants Stellar IMF IMF variation at high-z theoretical model highly star-forming bottom-light IMF starbursts bottom-heavy starbursts bottom-light/top-heavy descendant bottom-heavy IMF 18

19 Flow of story Stellar IMF Rest-frame Ultraviolet & Optical Spectral Characterization AGN Content Rest-frame Ultraviolet & Optical Spectral Characterization rest-frame optical observation optical DSFGs Swinbank et al. (2004) Hα emission 30 [NII]/Hα Hα line width -> 40 % AGN 19

20 Rest-frame Ultraviolet & Optical Spectral Characterization rest-frame optical observation Fig. 26 SMG composite rest-frame optical/uv Rest-frame Ultraviolet & Optical Spectral Characterization rest-frame optical observation Hα line width ~400 km/s, spatial extent < 4-8 kpc dynamical mass ~ M dynamical time Myr CO observation massive, metal-rich SMGs SFR Hα SFR FIR SFR factor 10 non-negligible AGN massive, local elliptical galaxies progenitor? 20

21 Rest-frame Ultraviolet & Optical Spectral Characterization rest-frame UV observation Chapman et al. (2005) rest-frame optical rest-frame UV factor 10 extinction SMG UV luminosity factor ~120 underestimate UV spectral index β = 1.5 ± 0.8 Calzetti extinction law -> E(B V) = 0.14 ± 0.15 LBG Rest-frame Ultraviolet & Optical Spectral Characterization rest-frame UV observation Chapman et al. (2005) SMG redder slope redder : shorter wavelength detect SMG median SMG bluer unobscured SMG β = 1.5 ± 0.8 -> L IR /L UV ~ 10 Meurer et al. (1999) attenuation relation 21

22 Rest-frame Ultraviolet & Optical Spectral Characterization rest-frame UV observation Reddy et al. (2012) UV spectral slope GOODS-Herschel stacked data attenuation and reddening slope local starbursts calibrate consistent dust property z~2 luminous DSFGs Rest-frame Ultraviolet & Optical Spectral Characterization another observation Banerji et al. (2011) z ~ 1.5 SMG (+SFRGs) [OII] Swinbank et al. (2004) z ~ 2 SMGs line width high-z, high-luminous SMGs dynamical mass evolutionary history large-scale wind outflow momentum-driven wind model V SFR 0.3 low-z ULIRGs consistent 22

23 Flow of story Stellar IMF Rest-frame Ultraviolet & Optical Spectral Characterization AGN Content AGN Content galaxy evolution host galaxy SMBH AGN starburst classic evolutionary sequence merger -> starburst -> quasar -> elliptical integrated BH growth ~30 % AGN X-ray <- detect radio emission, optical line, NIR color, mid-ir continuum, etc 23

24 AGN Content X-ray observation for AGN μm-selected galaxies number statistics (N source < 100) AGN activity star formation (from HMXBs, High-Mass X-ray Binaries) timeintensive/deep AGN fraction X-ray SFR NIR/FIR AGN Content X-ray observation for AGN Alexander et al. (2005a) radio-selected SMGs 75 % AGN 1/3 luminous AGN AGN SMGs X-ray emission star-formation HMXBs Wang et al. (2013a) ALMA-confirmed 870 μm-selected sources X-ray/FIR 24

25 AGN Content X-ray observation for AGN Alexander et al. (2008) X-ray + Hα (Hβ) line central BH mass BH-to-galaxy mass ratio local factor 3~5 high-z AGN AGN Content X-ray observation for AGN Fig. 27 X-ray observation summery 25

26 AGN Content optical observation for AGN high column density soft X-ray X-ray multi-wavelength emission line ratios optical diagnostics AGN activity DSFGs high-quality/high-sn spectrum AGN Content NIR/mid-IR observation for AGN SED NIR/mid-IR portion AGN blackbody Wien side power-law AGN warm dust ( K) mid-ir output dominant stellar mass 24 μm-based SFR contami star formation emission line old populations starlight, AGN-heated warm dust emission mid-ir spectrum 26

27 AGN Content NIR/mid-IR observation for AGN Lacy et al. (2004) & Stern et al. (2005) AGN identify mid-ir color selection technique SST bandpass Donley et al. (2012) deep IRAC data color-selection wedges starformation contami Flow of story Mid-Infrared Diagnostics Mid-Infrared Spitzer-selected Populations Kinematics 27

28 Mid-Infrared Diagnostics mid-ir feature FIR cold dust modified blackbody emission narrow gas emission line dominant mid-ir heavy molecules emission small dust grains absorption warm dust continuum Mid-Infrared Diagnostics mid-ir feature PAH (Polycyclic Aromatic Hydrocarbon) Å heavy molecules young star 3-19 μm SFR (PAH PDR ) dust silicate mid-ir ~8 μm ~11 μm PAH emission 9.7 μm dust silicate absorption 28

29 Mid-Infrared Diagnostics mid-ir feature warm dust continuum relative dust distribution bolometric heating sources star formation -> hot-to-cold dust ratio 1/1000 AGN -> relative dust temperature distribution mid-ir physical interpretation Mid-Infrared Diagnostics AGN contribution to mid-ir mid-ir SMG 80 % broad PAH emission feature dominant 20 % AGN dominant mid-ir continuum slope α = 2 ( ) Menéndez-Delmestre et al. (2009) 6.2 μm 7.7 μm PAH emission ratio local ULIRG nuclear starbursts local ULIRG dust temperature distribution 29

30 Mid-Infrared Diagnostics AGN contribution to mid-ir Fig. 28 non-agn dominated SMGs mid-ir spectrum Mid-Infrared Diagnostics main sequence or starburst Elbaz et al. (2011) Herschel-PACS data mid-ir analysis IR8 parameter IR luminosity PAH strength local LIRG/ULIRG IR8 <- PAH main sequence galaxies -> local LIRG consistent starbursts -> local ULIRG consistent z = 1~2 ULIRG main sequence IR8 consistent Herschel-PACS-selected galaxies merger-dominated 30

31 Mid-Infrared Diagnostics main sequence or starburst Lee et al. (2013) mid-ir/fir survey depth z ~ 2 ULIRG less luminous sources IR8 mid-ir optical IR main sequence FIR SFR IR8 starburst indicator observational assumptions biases Flow of story Mid-Infrared Diagnostics Mid-Infrared Spitzer-selected Populations Kinematics 31

32 Mid-Infrared Spitzer-selected Populations DOG (Dusty Obscured Galaxy) 24 μm-selected galaxies mid-ir excess integrated IR color 8 μm emission AGN-heating or bright PAH emission line AGN fraction Brand et al. (2006) AGN fraction = 9 % at S 24 = 350 μjy, 74 % at S 24 = 3 mjy Mid-Infrared Spitzer-selected Populations DOG (Dusty Obscured Galaxy) stellar mass NIR-bump massive stars opacity rest-frame 1.6 μm mid-ir bump -> star formation dominated mid-ir power-law -> AGN dominated Bussmann et al. (2009, 2011) z ~ 2 power-law/bump DOGs HST morphologies bump power-law merger-driven scenario bump-dogs morphology 32

33 Flow of story Mid-Infrared Diagnostics Mid-Infrared Spitzer-selected Populations Kinematics Kinematics kinematic studies photometric/spectroscopic expensive HII region Swinbank et al. (2006) etc 2.0 < z < SMGs merger-driven history (???) many at an early stage first pass ~ 33

34 Kinematics kinematic studies Fig. 29 SMGs line-profile characteristics Flow of story Physical Size and Morphology Relationship to Normal Galaxies: the Infrared Main Sequence The FIR/Radio Correlation 34

35 Physical Size and Morphology physical size of SMGs physical size optical/nir stellar continuum IR interferometric observation in the mm/radio DSFGs (optical ) CO size SMG effective radii = 2 ± 1 kpc -> local ULIRG 2 size molecular gas mass 2 -> scaled-up versions comparable mass disk galaxies >8 kpc Physical Size and Morphology physical size of SMGs gas size high-j CO transitions CO(1-0) emission line width velocity size MERLIN high-j molecular gas size 2 kpc radio continuum dense star formation areas SMG size Eddinton limit ~8 kpc source unresolved point-sources 35

36 Physical Size and Morphology morphology of SMGs morphology underlying physical process FIR region starburst Eddinton-limit -> star formation feedback model radio morphology local FIR/radio correlation FIR region size FIR morphology high-z SMGs local ULIRGs luminosity density IR region Physical Size and Morphology morphology of SMGs optical/nir dust obscuration Kartaltepe et al. (2007) z ~ 1.2 optical-luminous galaxies 70 μm-selected DSFG interaction Kartaltepe et al. (2012) high-resolution CANDELS survey Herschel-PACS-selected galaxies visual classifications ULIRGs z ~ 2 interaction 36

37 Physical Size and Morphology morphology of SMGs Physical Size and Morphology morphology of SMGs Swinbank et al. (2010) z ~ μm-selected SMGs size/morphology r i = 2.3 ± 0.3 kpc, r H = 2.8 ± 0.4 kpc band structured dust obscuration Sersic indices H-band light fit galaxy light distribution spheroidal/elliptical SMG stellar density local early type galaxies red, dense z ~ 1.5 galaxy (SMG s descendant) comparable/a bit higher 37

38 Physical Size and Morphology morphology of SMGs lensed galaxies gas, dust and stellar distribution size Hezaveh et al. (2012) lensed galaxy size distribution compact bias Flow of story Physical Size and Morphology Relationship to Normal Galaxies: the Infrared Main Sequence 5.12 The FIR/Radio Correlation 38

39 Relationship to Normal Galaxies: the Infrared Main Sequence main sequence stellar mass SFR (Noeske et al, 2007b, a) high-z stellar mass SFR optically-selected galaxy dustier galaxies (Daddi et al. 2007b) first order SFR IGM gas accretion rate starburst galaxies main sequence -> ssfr main sequence Relationship to Normal Galaxies: the Infrared Main Sequence SFR-M relation SFR SFR tight Stark et al. (2009) & Papovich et al. (2011) 3 < z < 8 SFR stellar mass rest-frame UV luminosity function observed main sequence 39

40 Relationship to Normal Galaxies: the Infrared Main Sequence relationship between DSFGs and main sequence DSFG SFR SFR-M stellar mass SMG stellar mass (Hainline et al., 2011) main sequence (Michalowski et al., 2012) main sequence high-mass, high-sfr Relationship to Normal Galaxies: the Infrared Main Sequence building up stellar mass via merger major merger stellar mass high-z main sequence galaxies low-z merger interaction main sequence galaxy merger origin Hainline et al, 2011 stellar mass burst stellar mass 70 % higher mass Michalowski et al,

41 Relationship to Normal Galaxies: the Infrared Main Sequence merger or disk Hung et al. (2013) merger rate IR luminosity (or SFR) IR-luminous systems merger rate local luminosity cutoff (local > L merger) ssfr cutoff obscured/unobscured galaxies merger fraction main sequence galaxies sample Relationship to Normal Galaxies: the Infrared Main Sequence recent situation IR (or bolometric) luminosity merger DSFGs origin dominate SMG-like luminosity merger SMG burst main sequence SMG massive luminous main sequence 41

42 Flow of story Physical Size and Morphology Relationship to Normal Galaxies: the Infrared Main Sequence The FIR/Radio Correlation The FIR/Radio Correlation FIR/radio correlation van der Kruit, P.C. (1971, 1973) luminosity 5 ~1.4 GHz emission 10 μm IR/radio emission Harwit & Pacini (1975) IR emission dust thermal re-radiation, radio emission supernova remnant IR emission 1980 (IRAS) 42

43 The FIR/Radio Correlation FIR/radio correlation q IR parameter IRAS era recently (Ivison et al, 2010a) local starburst q IR = 2.34 ± 0.72 (Yun et al., 2001) The FIR/Radio Correlation FIR/radio correlation evolution with redshift Magnelli et al. (2010) SMG OFRG q IR = 2.17 ± 0.19 DSFGs FIR excess q IR Ivison et al. (2010a, b) BLAST and Herschel-selected samples q IR 1 + z 0.26±0.07, q IR 1 + z 0.15±0.03 Casey et al. (2012a) z ~ 2 Herschel-selected DSFGs -> q IR 1 + z

44 The FIR/Radio Correlation FIR/radio correlation evolution with redshift IR-selected galaxies selection bias Ivison et al. (2010b) q IR radio/ir sample Sargent et al. (2010) selection bias FIR/radio correlation The FIR/Radio Correlation spectral index radio spectral index α = 0.8 (Condon, 1992) Ibar et al. (2009) fainter radio sources Ivison et al. (2010a, b) α = 0.75 ± 0.06 redshift α 1 + z 0.14±

45 The FIR/Radio Correlation usage of FIR/radio correlation IR data L IR SED characteristics ( dust temperature) obscured SFR radio submm beamsize multi-wavelength counterpart obscured SFR distribution FIR/radio correlation galaxy-scale morphology The FIR/Radio Correlation underlying physics Volk (1989) & Lisenfeld et al. (1996) cooling timescale electron % νl ν L IR radio spectral index steep Brems ionization flat cosmic ray proton cooling 45