Ithaca - 19 Jun 2006 VC The IRS GTO ULIRG Program

Ithaca - 19 Jun 2006 VC The IRS GTO ULIRG program - details Of the 110 sources Flux limited: 32 have S 25  0.3 Jy and log L FIR  L . We are observing all 32 in low and high-res modes. High redshift: 27 have z  0.3. GTO1-: 12/27 are being observed in low and high-res. + GTO2 (all rest) High luminosity: 11 sources have log L FIR  12.5 L . 10/11 are being observed in low and high-res.. Mix of Far-IR colors: 68 are “cold” (S 25 /S 60 < 0.2) and 21 are “warm”. This is a higher fraction of warm sources than in a flux-limited survey (typically ≤ 10%). GO Programs: Veilleux et al., Lutz et al., Imanishi et al., Verma et al. Sturtm et al. Additional IRS spectroscopy of ~30 “Template” galaxies “usual suspects” Weedman et al. 2005, Brandl et al (submitted), Devost et al (in prep)

Ithaca - 19 Jun 2006 VC Diversity! in the mid-IR spectra of ULIRGs AGN Starburst Embedded

Ithaca - 19 Jun 2006 VC Rigopoulou et al IRS Spectra of BGS Sources Armus et al ISO PHT-S spectra of BGS Sources

Ithaca - 19 Jun 2006 VC Spoon et al. 2004, A&A, 414,873 Arp220

Ithaca - 19 Jun 2006 VC Normalized BGS spectra Armus et al. 2006

Ithaca - 19 Jun 2006 VC Armus et al Quantifying the contribution of accretion to a SMBH - and a Staburst to the total mid-IR flux AGN Tracer: [NeV] at 14.3μm / 23.2μm (Ep~97eV) Starburst Tracers: [NeII] at 12.83μm (Ep~21eV) Presence of PAHs 6.2μm EQW

Ithaca - 19 Jun 2006 VC AGN starburst ULIRG Armus et al Quantifying the contribution of the energy from the AGN to the total IR luminosity

Ithaca - 19 Jun 2006 VC starburst ULIRG AGN [NeV] not detected in deeply obscured ULIRGs: Is the AGN NLR fully obscured?

Ithaca - 19 Jun 2006 VC Rising slope of thermal emission from the AGN torus from 2-5μm due to grains radiating in near-equilibrium Excess over starlight at ~4-5μm “Laurent Diagram” Alonso-Herrero et al f(5μm)~10Jy z~0.004 D~14Mpc f(5μm)~7mJy z~0.9 D~5.8Gpc FSC AGN thermal emission in mid-IR continuum

Ithaca - 19 Jun 2006 VC Decomposition of the Infrared Spectrum Core of the method  Assume absorption cross sections from Li & Draine (2001) and an MRN grain-size distribution  Calculate the opacities of PAH, graphitic and smoothed astronomical silicate grains.  Each dust component has a quasi-fixed temperature i.e.. the fitting process is really an expansion into several temperature basis components.  The number of dust components is fixed for the sample so that all galaxies are fit in a uniform manner.  In addition to a ~3500 K stellar blackbody and PAH component, we find that we need ~3 additional continuum dust components with T~400, ~150, and ~30 K to accurately fit the entire sample.  An AGN manifests its presence with the requirement of an additional hot dust component T~800K (Laurent et al. 2000)  Talk to Jason Marshall !

Ithaca - 19 Jun 2006 VC Decomposition of Arp220 T Cold =31K T Warm =96K T Hot =873K L Hot /L Total =0.005 L 1-40 /L Total =0.19 L PAH /L Total =0.004

Ithaca - 19 Jun 2006 VC Decomposition of Mrk231 T Cold =38K T Warm =151K T Hot =486K L Hot /L Total =0.13 L 1-40 /L Total =0.52 L PAH /L Total =0.006

Ithaca - 19 Jun 2006 VC Conclusions based on the BGS ULIRGs AGN fraction estimates based on various methods

Ithaca - 19 Jun 2006 VC

Ithaca - 19 Jun 2006 VC Quantifying the contribution of the energy from the AGN Using the “Laurent Diagram” Armus et al. 2006