FIRSED 2013: Nearby Galaxies

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1 FIRSED 2013: Nearby Galaxies

2 FIRSEDs of Nearby Galaxies: Key Applications Diagnostics of interstellar dust dust masses, surface density distributions temperatures, compositions, size distributions independent constraints on cold gas distributions and X(CO) Dust-obscured star formation star formation rate (SFR) is strongly correlated with gas (and dust) surface density, so the IR probes the densest and most intense star forming regions testbed for multi-wavelength SFR diagnostics, star formation laws Spectral diagnostics of the cool atomic and molecular ISM

3 New Capabilities with Herschel Extended wavelength coverage to 500 mm accurate measurements of bolometric dust emission, reprocessed starlight complete SED templates, bolometric corrections for monochromatic IR fluxes truly robust measures of dust masses, surface densities, dust/gas ratios (DGRs) better constraints on dust temperatures, emissivities an independent path to measuring gas surface densities, X(CO) Few-arcsecond resolution at the peak of the dust SED spatially-resolved SFRs on scales where cloud/cluster formation is triggered clean separation of dust-heating stellar populations vs wavelength Statistically robust, complete galaxy samples

4 Dissecting a Galaxy s SED Spitzer Herschel SCUBA LABOCA

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6 Herschel Nearby (Normal) Galaxy Surveys Survey N Distance Selection PACS SPIRE Spec KINGFISH/SINGS Mpc diversity X X X Very Nearby Galaxy Survey Mpc diversity X X X Herschel Reference Survey Mpc flux, vol X X Herschel Dwarf Galaxy Survey Mpc mass X X X HeViCS (Virgo Cluster Survey) ~ Mpc flux, vol X X HeFoCS (Fornax Cluster Survey) 17 Mpc flux, vol X X HERITAGE 2.05/.06 Mpc LMC/SMC X X HERM33ES Mpc M33 X X X HELGA Mpc M31 X X

7 For an interactive version go to:

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9 Recent Results A Herschel Sampler FIRSEDs systematic properties of FIRSEDs along the Hubble sequence estimators of bolometric dust luminosities and SFRs Dust properties of normal galaxies dust masses, global dust properties dust mapping dust temperatures and emissivities constraints on dust heating and heating populations submillimetre excess emission Applications IRX-beta relation constraining gas density distributions and X(CO) conversion factor

10 SFR log L TIR KINGFISH Sample -- (Dale et al 2012)

11 HRS Boselli et al 2012

12 Combining Herschel and Spitzer data to create bolometric L TIR maps KINGFISH Galametz et al 2013

13 How accurately does a single waveband predict L(TIR)? Galametz et al 2013)

14 residuals are strongly correlated with IR colour (not surprisingly) bolometric fraction vs waveband

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16 Residuals on monochromatic calibration Galametz et al 2013) Magnelli et al., 2012 Wu et al., 2012 Eisenhardt et al., 2012 Le Floc h et al., 2012 Rangwala et al., 2011

17 Star formation rates (SFRs) from the FIRSED From bolometric energy arguments: - SFR (M o /yr) = ( ) x L TIR (ergs/s) depending on IMF - SFR above only traces dust-absorbed component - conversion factor in practice is scale dependant Calzetti et al 2010

18 Dust-corrected SFRs from combining UV and FIR emission Hao et al 2011

19 Multiwavelength observations provide dust-free SFR tracers Kennicutt et al. 2009

20 Dust heating sources vs wavelength (VNGS Bendo et al 2012)

21 Dust heating sources vs wavelength Bendo et al 2012

22 Calibration coefficients change as a function of the region physical size KINGFISH Li et al 2013

23 HRS Boselli et al 2012

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25 HRS Boselli et al 2012

26 PAH emission disappears at low metallicity, but is this causation or correlation? Marble et al 2010 LVL survey Gordon et al 2008 M101

27 F ν (Jy) F ν (Jy) Two-modified blackbody fitting Global cold dust properties NGC 0337 L(λ) = λ -2 B(T warm ) + λ -βcold B(T cold ) NGC Wavelength (μm) Wavelength (μm)

28 KINGFISH Aniano et al 2012

29 HRS Cortese et al 2012

30 Dependence of dust masses on wavelength coverage and assumed emissivity (KINGFISH Galametz et al 2012)

31 T β correlation Individual pixels in the T cold β cold parameter space Eddington bias? unlikely Changes in the emissivity index? Mixture of temperatures along the line of sight?

32 cold gas surface density dust mass surface density dust luminosity surface density dust/gas ratio map KINGFISH Aniano et al 2012

33 PAH grain mass fraction diffuse radiation field fraction of dust luminosity from intense grain heating

34 Peaks in dust temperature and dust density do not always coincide (Foyle et al 2012 VNGS)

35 Application: Variations in the CO/H 2 X (a) Conversion Factor Sandstrom et al 2013 (KINGFISH) (also see Leroy et al 2011, Eales et al 2012)

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37 Leroy et al 2011) Sandstrom et al 2013)

38 One Final Application: IRX-beta Relation Dale et al 2009 Spitzer LVL survey Boquien et al 2012 HRS (also see Mao et al 2012)

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40 Team UK: Rob Kennicutt (PI), Maud Galametz France: Gonzalo Aniano, Pedro Beirao, Ben Johnson, Helene Roussel, Marc Sauvage, Laurent Vigroux Germany: Brent Groves, Kathryn Kreckel, Oliver Krause, Sharon Meidt, Hans- Walter Rix, Karin Sandstrom, Eva Schinnerer, Fatemeh Tabatabaei, Tessel van der Laan, Fabian Walter Italy: Leslie Hunt, Stefano Zibetti Netherlands: Bernhard Brandl, Ainil Abdullah Canada: Christine Wilson China: Caina Hao U.S.: Phil Appleton, Daniela Calzetti (Deputy PI), Phil Appleton, Lee Armus, Alberto Bolatto, Alison Crocker, Kevin Croxall, Danny Dale, Jennifer Donovan Meyer, Bruce Draine, Chad Engelbracht, Karl Gordon, George Helou, Joannah Hinz, Jin Koda, Adam Leroy, Yiming Li, Ed Montiel, Eric Murphy, Eric Pellegrini, Ramin Skibba, JD Smith, Mark Wolfire