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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)
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A Paradigm for SMBH Activity What ignites the AGN phase? –Galaxy mergers? (Taniguchi 1999, di Matteo et al. 2005) –Disk galaxy star formation? (Hopkins & Hernquist 2006) Why do AGNs look so different? –Broad / narrow emission lines, luminosity, SED vary widely –Caused by different obscuration, or accretion physics? Is there an AGN Unified Model???
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COSMOS AGN survey Four years of Magellan/IMACS & MMT/Hectospec spectroscopy over 2 deg 2 –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
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COSMOS Sensitivity to AGN SEDs ~40 times fainter than the typical SDSS quasar Sensitive to QSO/Seyfert boundary at z~2 Multiwavelength, for full SED X-ray selection for varied AGN types SDSS SED, z~1.5 (Richards et al. 2007) Arp 220, z~1.5 (Silva 1998)
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Accurate bolometric luminosities Model SED as accretion disk + X-ray corona Top: BL Bottom: NL (with host galaxy) Ignore extra reprocessed IR emission
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Broad-Line AGN Masses M BH ~ L 0.5 × v fwhm 2, scatter of ~0.4 dex Calibrated from reverberation mapping of ~30 local AGN Virial theorem: M BH ~ R BLR v BLR 2 R BLR ~L 0.5 (Kaspi et al. 2000, 07): scaling relations
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Masses for Narrow-Line and Lineless AGNs No broad emission lines... host – M BH relations instead log(M BH /M ⊙ ) ~ 0.9 log(L K,bulge ) − 31 ~ 0.35 dex scatter Bulge luminosities from HST/ACS decompositions (Gabor+09) Graham 2007
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AGN Fueling L I /L Edd : accretion rate With L disk /L X, E peak of disk, X-ray slope
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AGN Fueling Broad-Line AGN Obscured Narrow-Line AGN Unobscured Narrow-Line & Lineless AGN
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AGN Fueling Broad-line and Obscured Narrow-Line AGN limited by L/L Edd > 0.01
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AGN Fueling (unobscured only) Disk gets brighter & hotter as accretion rate increases (at >3σ significance)
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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)
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Accretion Rate and the IR “Torus” Hot “torus” dust will have IR signature from 1-10μm with α IR <0.5 Weak AGNs lack this IR signature Can be explained by disk wind of both BLR & clumpy dust
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AGN Fueling With increasing accretion rate (L I /L Edd )… –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 L I /L edd >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)
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Accretion in AGN Unification L I /L Edd < 0.01 L I /L Edd > 0.01
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Reverberation Mapping Measure time delay between variability in the broad lines and the continuum Virial theorem: M BH ~ R BLR v BLR 2 R BLR =ct lag v BLR =v FWHM Calibrator for all non- local M BH !!!
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Previous AGN RM Typical t lag ~ 5-100 days Previous work has been mostly single- target spectra on small telescopes –~45 AGNs, all but 1 at z<0.4 –Almost all Hβ (1 with MgII, 3 with CIV) This work: the first multi-object RM study –37 AGNs, with 31 at 0.4 < z < 2.8 –12 with Hβ, 26 with MgII, 13 with CIV Double total sample, 10x more at high-z!
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Evolution in M BH -M Host ? Weak evidence for more massive BH compared to host with redshift Relies on M BH uncertain to >0.4 dex from “scaling relations” RM at z>1 could give M BH to ~0.2 dex! from Merloni et al. 2010
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Spectral variability with Hecto Need accurate differential spectrophotometry –Fiber throughput differences: same rotator angle Feb–May, always same fiber–target –Weather variation: stars in target slits as standards –Fiber flexure: ancillary photometry (Bok/90’) –Sky variations within the 1° field: 4+ sky fibers per target in same mask region Queue mode: 1 hr/night, total of 5 nights
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What we got… Weather & scheduling: gaps in Jan/Mar/Jun Actual variability Simulated continuum flux (+) Simulated line fluxes Time lags using cross- correlation functions
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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Time Series Spectra CIV MgII HβHβ
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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/L Edd < 0.01 –Torus weakens at low accretion rate? Only possible with COSMOS!!! Reverberation mapping for more accurate M BH in progress
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