J/ApJ/691/705       AGN host galaxy morphologies in COSMOS        (Gabor+, 2009)
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Active galactic nucleus host galaxy morphologies in COSMOS.
    Gabor J.M., Impey C.D., Jahnke K., Simmons B.D., Trump J.R.,
    Koekemoer A.M., Brusa M., Cappelluti N., Schinnerer E., Smolcic V.,
    Salvato M., Rhodes J.D., Mobasher B., Capak P., Massey R., Leauthaud A.,
    Scoville N.
   <Astrophys. J., 691, 705-722 (2009)>
   =2009ApJ...691..705G
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ADC_Keywords: Galaxies, optical ; Active gal. nuclei ; Photometry, HST ;
              Morphology ; Redshifts ; Surveys
Keywords: galaxies: active - galaxies: evolution - galaxies: interactions -
          galaxies: structure

Abstract:
    We use Hubble Space Telescope/Advanced Camera for Surveys images and
    a photometric catalog of the Cosmic Evolution Survey (COSMOS) field
    to analyze morphologies of the host galaxies of ~400 active galactic
    nucleus (AGN) candidates at redshifts 0.3<z<1.0. We compare the
    AGN hosts with a sample of nonactive galaxies drawn from the COSMOS
    field to match the magnitude and redshift distribution of the AGN
    hosts. We perform two-dimensional surface brightness modeling with
    GALFIT to yield host galaxy and nuclear point source magnitudes.
    X-ray-selected AGN host galaxy morphologies span a substantial range
    that peaks between those of early-type, bulge-dominated and late-type,
    disk-dominated systems. We also measure the asymmetry and
    concentration of the host galaxies. Unaccounted for, the nuclear point
    source can significantly bias results of these measured structural
    parameters, so we subtract the best-fit point source component to
    obtain images of the underlying host galaxies. Our concentration
    measurements reinforce the findings of our two-dimensional morphology
    fits, placing X-ray AGN hosts between early- and late-type inactive
    galaxies. AGN host asymmetry distributions are consistent with those
    of control galaxies.

Description:
    COSMOS (Scoville et al. 2007ApJS..172....1S), a Hubble Space Telescope
    Treasury project, includes coverage of a 2deg^2^ field from X-ray
    wavelengths to UV, optical, IR, and radio. The cornerstone data set,
    which we use for the bulk of our analysis, consists of 583 orbits
    taken with Hubble's Advanced Camera for Surveys (ACS) with the F814W
    filter (see Koekemoer et al. 2007ApJS..172..196K for a complete
    description). Ancillary observations include XMM-Newton X-ray imaging
    (Hasinger et al. 2007, Cat. J/ApJS/172/29), VLA radio maps (Schinnerer
    et al. 2007, Cat. J/ApJS/172/46), and VLT/VIMOS (Lilly et al. 2007,
    Cat. J/ApJS/172/70) and Magellan/IMACS optical spectroscopy (Trump et
    al. 2007, Cat. J/ApJS/172/383; 2009ApJ...700...49T; 2009ApJ...706..797T).

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table2.dat    134      391   Results of 2-D fits
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See also:
   II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
   J/ApJS/172/29  : XMM-Newton survey in COSMOS field. I. (Hasinger+, 2007)
   J/ApJS/172/46  : VLA-COSMOS survey. II. (Schinnerer+, 2007)
   J/ApJS/172/383 : AGN candidates in the COSMOS field (Trump+, 2007)
   J/ApJS/172/70  : zCOSMOS-bright catalog (Lilly+, 2007)
   J/ApJS/172/368 : XMM-Newton survey in COSMOS field. IV. (Mainieri+, 2007)
   J/A+A/512/A34  : XMM-COSMOS Type 1 AGNs (Lusso+, 2010)

Byte-by-byte Description of file: table2.dat
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   Bytes Format Units   Label     Explanations
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   1-  7  A7    ---     ---       [COSMOS_]
   8- 26  A19   ---     COSMOS    Object identification (JHHMMSS.ss+DDMMSS.s)
  28- 35  F8.4  deg     RAdeg     Right Ascension in decimal degrees (J2000) (1)
  37- 42  F6.4  deg     DEdeg     Declination in decimal degrees (J2000) (1)
  44- 47  F4.2  ---     z         Spectroscopic redshift (2)
  49- 53  F5.2  mag     mh        Host galaxy apparent HST F814W magnitude (3)
  55- 58  F4.2  mag   e_mh        Uncertainty estimate in Imagh (4)
  60- 64  F5.2  mag     mh*       Host galaxy apparent F814W magnitude without
                                  nuclear point source component (3)
  66- 71  F6.2  pix     rp        Host galaxy effective F814W image radius (3)
  73- 78  F6.2  pix   e_rp        Uncertainty estimate in rp (4)
  80- 85  F6.2  pix     rh*       Host galaxy effective F814W image radius
                                  without nuclear point source component (3)
  87- 90  F4.2  ---     nh        Host galaxy Sersic index (3)
  92- 95  F4.2  ---   e_nh        Uncertainty estimate in nh (4)
  97-100  F4.2  ---     nh*       Host galaxy Sersic index without nuclear point
                                  source component (3)
 102-106  F5.2  mag     mp        Nuclear point source HST F814W magnitude (3)
 108-111  F4.2  mag   e_mp        Uncertainty estimate in Imagp (4)
 113-116  F4.2  ---     A         Asymmetry morphological indicator
 118-122  F5.2  ---     C         Concentration morphological indicator (5)
 124-128  F5.1  pix     rn0       Petrosian radius
     130  I1    ---     Flag      Fit flag (0=OK) (6)
 132-134  A3    ---     Class     Spectral class (7)
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Note (1): Positions are for optical counterparts to the XMM-Newton X-ray
          point-source catalog (Cappelluti et al. 2007ApJS..172..341C) and the
          VLA radio source catalog (Schinnerer et al. 2007, Cat. J/ApJS/172/46).
Note (2): Redshifts are derived from optical spectra from Magellan/IMACS and
          MMT/Hectospec (Trump et al. 2007, Cat. J/ApJS/172/383).
Note (3): Best-fit morphological parameters based on 2-D surface brightness
          fits (1 pixel=0.03").
Note (4): Based on fits to our simulated AGN images, and give the 1-{sigma}
          scatter on each parameter for an AGN with the given mean surface
          brightness.
Note (5): The concentration parameter serves as an alternative to the Sersic
          index to determine whether a galaxy is dominated by a highly
          concentrated central bulge component. Here we define the concentration
          as C=5log(r_>_/r_<_), with r_>_=0.9r_{eta}0_ and r_<_=0.5r_{eta}0_.
Note (6): Fit flags as follows:
    0 = Successful automated fit;
    1 = Fit runs into boundaries;
    2 = Successful manual fit;
    3 = Fit better without PSF component;
    4 = Poor fit (subjective).
Note (7): From Trump et al. (2007, Cat. J/ApJS/172/383). The first letter
     indicates X-ray ("x") or radio ("r") selected objects, and the numbers
     indicate optical spectral types as follows:
    1 = Broad line AGN,
    2 = Narrow lines,
   23 = Hybrid Narrow line/Red galaxy,
    3 = Red Galaxy.
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History:
    From electronic version of the journal

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(End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    22-Feb-2011