Dusty star-forming galaxies at high redshift (part 5)

Transcription

1 Dusty star-forming galaxies at high redshift (part 5) Flow of story Acquiring Spectroscopic or Photometric Redshifts Infrared SED Fitting for DSFGs Estimating L IR, T dust and M dust from an SED 1

2 Infrared SED Fitting for DSFGs FIR SED fitting dust emission infrared luminosity obscured star formation rate dust temperature and dust mass template libraries scaling relations direct data fitting, parametrized fits Infrared SED Fitting for DSFGs FIR SED fitting photometric data model FIR emission dust distribution composition dust grain type orientation galaxy structure band parameter AGN heating emissivity and optical depth etc 2

3 Infrared SED Fitting for DSFGs FIR SED fitting CO, CII emission line broadband submm flux densities % contaminate SED fitting techniques direct comparison to models using Bayesian techniques modified black body functions stellar emission dust emission fit Flow of story Employing dust radiative transfer models and empirical templates Direct modified blackbody SED modeling 3

4 Employing dust radiative transfer models and empirical templates geometry luminosity dust infrared emission modeling accuracy applicability geometry distribution, optical depth high-z dusty starbursts SED fitting Employing dust radiative transfer models and empirical templates Silva et al UV FIR / stellar population synthesis models code age metalicity SFR gas fraction integrated spectra dust geometry chemical evolution dust grain size distribution relative gas trapped in MC versus diffuse ISM 4

5 Employing dust radiative transfer models and empirical templates Chary & Elbaz 2001 Silva et al z ~ 1 infrared-luminous galaxies SED population CIB mid-ir ISOCAM data 4 (Arp 220, NGC 6090, M82, M51) SED 20 μm Dale et al Employing dust radiative transfer models and empirical templates Dale et al dust emission curves dust mass distribution power-law FIR small, large, PAH grains 69 data normal galaxies S 60 /S 100 Dale & Helou 2002 Dale et al >120 μm 5

6 Employing dust radiative transfer models and empirical templates Dopita et al UV FIR, radio SED STARBURST99 (Leitherer & Heckman 1995) model nebular line emission model dynamic evolution model of HII regions simplified synchrotron emissivity model stellar population synthesis model solar-metalicity starburst self-consistent SED FIR emission starburst ambient pressure Employing dust radiative transfer models and empirical templates Chary & Elbaz 2001 Dale & Halou 2002 template mid-ir detect FIR luminosity data model 6

7 Employing dust radiative transfer models and empirical templates Siebenmorgen & Krügel 2007 dusty starburst nuclei and ULIRGs dust clumpiness asymmetry model local or high-z galaxies 7000 template SEDs Draine & Li 2007 mid-ir dust emission Spitzer data Employing dust radiative transfer models and empirical templates Rieke et al Spitzer local (U)LIRGs data 0.4 μm 30 cm, L template 35 μm IRS ISO spectrum 0.4 μm - 5 μm stellar photospheric template redshift consistent FIR K modified black body (β = 0.7 ~ 1) 7

8 Employing dust radiative transfer models and empirical templates Bayesian fitting CIGALE (Code Investigating GALaxy Emission) optical/nir model spectra thermally pulsating AGB (TP-AGB) stars modified laws FIR SED templates (Dale & Helou 2002) synthetic dust attenuation curves Employing dust radiative transfer models and empirical templates Bayesian fitting MAGPHYS (Multi-wavelength Analysis of Galaxy PHYSical properties) energy balance argument UV FIR IR SED <- hot grains, PAHs, grains in thermal equilibrium stellar component <- stellar population synthesis, attenuated spectrum da Cunha et al

9 Flow of story Employing dust radiative transfer models and empirical templates Direct modified blackbody SED modeling Direct modified blackbody SED modeling modified blackbody model 850 μm SMGs flux density -> L FIR or SFR modified black body local ULIRG SED template 850 μm flux density 3.5 S 850 L FIR T dust (z = 0 ~ 2) 9

10 Direct modified blackbody SED modeling modified blackbody model FIR/radio correlation radio FIR modified black body high-z (Ivison et al, 2010a, b) L IR FIR data fit SED modified black body 850 μm SMGs -> selection effect Direct modified blackbody SED modeling modified blackbody model Herschel PACS SPIRE FIR band data radio luminosity black body galaxies temperature variation dust emissivity variation in opacity S ν (T) 1 e τ ν B ν (T) assumed dust temperature 10

11 Direct modified blackbody SED modeling modified blackbody model Herschel PACS SPIRE FIR band data τ ν = Σ dust κ ν = ν/ν 0 β (ν 0 = THz) κ ν = κ 0 ν/ν 0 β emissivity index β unresolved distant DSFGs DSFG 450 μm optically-thin Direct modified blackbody SED modeling modified blackbody model Rayleigh-Jeans regime Wien regime rest-frame 8-50 μm hot dust small clump modified black body mid-ir flux density excess heating optically-thin medium (Scoville & Kwan, 1976) 11

12 Direct modified blackbody SED modeling modified blackbody model two component model 2 modified black body fit colder component longer-wavelength dominant warmer component mid-ir excess 10 high-z galaxies two component model unconstrained parameter normalization, emissivity) (dust temperature, Direct modified blackbody SED modeling modified blackbody model other methods longer wavelength modified black body fit shorter wavelength power-law fit 12

13 Direct modified blackbody SED modeling modified blackbody model other methods SED modified black body power-law T c : most massive dust Direct modified blackbody SED modeling modified blackbody model other methods power-law analytical approximation N bb, N pl : normalization factor ( free parameter) 13

14 Direct modified blackbody SED modeling modified blackbody model 2009 single temperature modified black body fit cold-dust modified black body + mid-ir powerlaw 3 fitting fitting method (Kelly et al., 2012) Flow of story Estimating L IR, T dust and M dust from an SED Luminosity Functions Contribution to Cosmic Star Formation Rate Density 14

15 Estimating L IR, T dust and M dust from an SED infrared luminosity from SED SED infrared μm (Kennicutt, 1998a) cold diffuse dust, hot dust, PAH, AGN heating emission AGN heating μm rest-frame 40 μm μm μm Estimating L IR, T dust and M dust from an SED SFR from SED L IR SFR dust compsition IMF (Initial Mass Function) (cf. Bastian et al. 2010) Kennicutt 1998a Leither & Heckman 1995 radiative transfer model Salpeter 1995 IMF AGN heating 15

16 Estimating L IR, T dust and M dust from an SED SFR from SED Swinbank et al Chabrier 2003 IMF Salpeter 1955 IMF factor 1.8 SFR local moderate-luminosity star-forming galaxies high-z extreme systems dust-heating source Estimating L IR, T dust and M dust from an SED T dust, M dust and β from SED T dust 1 T dust λ peak λ peak T dust model assumption dust opacity dominant emissivity index dust temperature 16

17 Estimating L IR, T dust and M dust from an SED T dust, M dust and β from SED T dust Fig 20. T dust λ peak Estimating L IR, T dust and M dust from an SED T dust, M dust and β from SED M dust SED R-J regime (S ν τb ν (T)) S ν = κ ν B ν T M dust D L 2 optically-thin approximation -> L ν S ν /B ν (T) ν μm optically-thin dust temperature dust mass (Draine & Li 2007) dust absorption coefficient dust mass 17

18 Estimating L IR, T dust and M dust from an SED T dust, M dust and β from SED M dust dust mass, dust temperature, flux density, IR luminosity 1 M dust S ν T dust (4+β) M dust L IR T dust dust mass gas-to-dust ratio gas mass gas-to-dust ratio Milky way local (U)LIRGs CO(1-0) observations -> gas-to-dust ratio = ~100 Flow of story 4.3 Estimating L IR, T dust and M dust from an SED Luminosity Functions Contribution to Cosmic Star Formation Rate Density 18

19 Luminosity Functions luminosity function SED fitting redshift z = 2 ~ 3 selection effect potential biasing incompleteness band luminosity functions Luminosity Functions luminosity function Le Floc h et al 2005 Spitzer 24 μm data z ~ 1 integrated IR luminosity function 24 μm data -> integrated infrared luminosity local scalings existing knowledge of mid-ir spectral features and their impact on 24 μm flux with redshift 19

20 Luminosity Functions luminosity function 1 / Vmax method z min, zmax : source detect min/max redshift high-z flux density source Caputi et al. 2007, Magnelli et al AKARI consistent (Goto et al. 2010) Luminosity Functions luminosity function Herschel IR emission peak Spitzer PACS SPIRE z ~ 3.6 luminosity functions 20

21 Luminosity Functions luminosity function Fig. 21 integrated luminosity function Luminosity Functions luminosity function Fig. 21 integrated luminosity function 21

22 Luminosity Functions luminosity function analytic approximation Schechter function double power-law local free parameter α σ 2 parameter L redshift (α σ ) high-l and low-φ fits -> low-l and high-φ fits Luminosity Functions luminosity function analytic approximation Fig. 21 L and Φ evolution with redshift 22

23 Flow of story Estimating L IR, T dust and M dust from an SED Luminosity Functions Contribution to Cosmic Star Formation Rate Density Contribution to Cosmic Star Formation Rate Density star formation rate density (SFRD) star formation IR galaxies high-z SFRD dust obscuration IR luminosity function luminosity function accessible volume 1 / Vmax method 23

24 Contribution to Cosmic Star Formation Rate Density infrared luminosity density (IRLD) L IR -> SFR survey depth area coverage IRLD (SFRD) IR luminosity (SFR) volume Lilly-Madau diagram (Lilly et al. 1995, Madau et al. 1996) SFRD, redshift (or look-back time) plot Contribution to Cosmic Star Formation Rate Density Lilly-Madau diagram (Lilly et al. 1995, Madau et al. 1996) Fig 23. SFRD (IRLD) redshift 24

25 Contribution to Cosmic Star Formation Rate Density Lilly-Madau diagram (Lilly et al. 1995, Madau et al. 1996) Fig 24. SFRD (IRLD) redshift Contribution to Cosmic Star Formation Rate Density Lilly-Madau diagram (Lilly et al. 1995, Madau et al. 1996) Fig. 23 incompleteness bias sample net contribution Chapman et l. 850 μm-selected galaxies -> 10% Fig. 24 population incompleteness equal luminosity 25

26 Contribution to Cosmic Star Formation Rate Density Lilly-Madau diagram (Lilly et al. 1995, Madau et al. 1996) ULIRG (e.g. Le Floc h et al. 2005) dominant z ~ 1 ~10 %, z ~ 2 ~50 % LIRG z ~ 1 peak ~50 % optical/rest-frame UV high-z SFRD dust-obscured star-formation 26