agn unification in cosmos
Post on 11-Jan-2016
29 Views
Preview:
DESCRIPTION
TRANSCRIPT
AGN Unification in COSMOS
Jonathan Trump
Chris Impey (Arizona), Martin Elvis, Brandon Kelly, Francesca Civano (CfA), Yoshi Taniguchi, Tohru Nagao
(Ehime), Knud Jahnke, Marcella Brusa, Mara Salvato (Max-Planck), Pat McCarthy (Carnegie), Anton Koekemoer
(STScI)
COSMOS AGN survey
• Four years of Magellan/IMACS & MMT/Hectospec spectroscopy over 2 deg2
– 4 magnitudes fainter than SDSS
– Type 1 AGN masses from virial scaling relations
– Faint and obscured AGNs to z~1
• HST/ACS data for host morphologies to z~1– Type 2 AGN masses from host-SMBH relations
• Complete SEDs– Deep radio, IR, optical, UV, X-ray photometry
– Bolometric luminosities
• Bolometric luminosity + Mass = Accretion Rate
Accurate bolometric luminosities
Model SED as accretion disk + X-ray corona
Top: BL
Bottom: NL (with host galaxy)
Ignore extra reprocessed IR emission
Broad-Line AGN Masses
• MBH ~ L0.5 × vfwhm2, scatter of ~0.4 dex
• Calibrated from reverberation mapping of ~30 local AGN
• Virial theorem: MBH ~ RBLRvBLR
2
• RBLR~L0.5 (Kaspi et al. 2000, 07): scaling relations
Masses for Narrow-Line and Lineless AGNs
• No broad emission lines... host – MBH relations instead
• log(MBH/M⊙) ~ 0.9 log(LK,bulge) − 31
• ~0.35 dex scatter• Bulge luminosities
from HST/ACS decompositions (Gabor+09)
Graham 2007
AGN Fueling
• LI/LEdd: accretion rate
• With Ldisk/LX, Epeak of disk, X-ray slope
AGN Fueling
Broad-Line AGNObscured Narrow-Line AGN
Unobscured Narrow-Line & Lineless AGN
AGN Fueling
• Broad-line and Obscured Narrow-Line AGN limited by L/LEdd > 0.01
AGN Fueling (unobscured only)
• Disk gets brighter & hotter as accretion rate increases (at >3σ significance)
Accretion Rate and Radio Jets
• Weakly accreting AGNs are more radio-loud!
• Weak AGNs may be important for radio-mode feedback (e.g. heating cluster cores, IGM enrichment)
Accretion Rate and the IR “Torus”
• Hot “torus” dust will have IR signature from 1-10μm with αIR<0.5
• Weak AGNs lack this IR signature
• Can be explained by disk wind of both BLR & clumpy dust
AGN Fueling
• With increasing accretion rate (LI/LEdd)…– Disk luminosity increases compared to X-rays– Disk becomes hotter– Weaker radio outflows– More likely to have IR “torus” signature– Broad emission lines appear (at LI/Ledd>0.01)
• Accretion rate is an “axis” of AGN unification– At low accretion rates, theory predicts a
radiatively inefficient accretion flow (RIAF) which can produce these effects (Narayan & McClintock 2008)
Accretion in AGN Unification
LI/LEdd < 0.01
LI/LEdd > 0.01
Reverberation Mapping
• Measure time delay between variability in the broad lines and the continuum
• Virial theorem: MBH ~ RBLRvBLR2
• RBLR=ctlag
• vBLR=vFWHM
• Calibrator for all non-local MBH!!!
Summary
• Accretion Rate: new axis in AGN Unification– Low accretion rate: RIAF at inner radii– RIAF: radio-loud, cooler + weaker disk
– BLR disappears at L/LEdd < 0.01
– Torus weakens at low accretion rate?
• Only possible with COSMOS!!!
• Reverberation mapping for more accurate MBH in progress
top related