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J/ApJ/660/167       Spitzer AGN candidates in CDFN           (Donley+, 2007)
Spitzer power-law active galactic nucleus candidates in the
Chandra Deep Field-North.
    Donley J.L., Rieke G.H., Perez-Gonzalez P.G., Rigby J.R., Alonso-Herrero A.
   <Astrophys. J., 660, 167-190 (2007)>
   =2007ApJ...660..167D
ADC_Keywords: Active gal. nuclei ; X-ray sources ; Radio sources ;
              Millimetric/submm sources
Keywords: galaxies: active - infrared: galaxies - X-rays: galaxies


Abstract:
    We define a sample of 62 galaxies in the Chandra Deep Field-North
    whose Spitzer IRAC SEDs exhibit the characteristic power-law emission
    expected of luminous AGNs. We study the multi-wavelength properties of
    this sample and compare the AGNs selected in this way to those
    selected via other Spitzer color-color criteria. Only 55% of the
    power-law galaxies are detected in the X-ray catalog at exposures of
    >0.5Ms, although a search for faint emission results in the detection
    of 85% of the power-law galaxies at the ≥2.5sigma detection level.
    Most of the remaining galaxies are likely to host AGNs that are
    heavily obscured in the X-ray. Because the power-law selection
    requires the AGNs to be energetically dominant in the near- and
    mid-infrared, the power-law galaxies comprise a significant fraction
    of the Spitzer-detected AGN population at high luminosities and
    redshifts. The high 24um detection fraction also points to a luminous
    population. The power-law galaxies comprise a subset of color-selected
    AGN candidates.

Description:
    Spitzer was used to obtain MIPS and IRAC MIR observations of the
    CDF-N, with 1400 and 500s exposures, respectively. We use these MIPS
    GTO images in place of the GOODS Spitzer data because the former cover
    the full CDF-N, whereas the latter cover a field approximately 2 times
    smaller.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat       109       62   Power-law galaxy sample
table5.dat        65      603   Templates

Objects:
    ----------------------------------------------------------
       RA   (2000)   DE    Designation(s)
    ----------------------------------------------------------
    15 34 57.2 +23 30 10   Arp 220 = IC 1127 
    17 23 21.9 -00 17 00   IRAS 17208-0014 = PMN J1723-0016
    13 44 42.1 +55 53 11   Mrk 273 = UGC 8696 
    ----------------------------------------------------------

See also:
    J/AJ/122/2810 : Chandra Deep Field North Survey. V. (Brandt+, 2001)
    J/AJ/124/2351 : Chandra Deep Field North survey. XII (Bauer+, 2002)
    J/AJ/126/539  : The Chandra Deep Fields North and South (Alexander+, 2003)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label     Explanations

   1-  4  A4    ---     ---       [CDFN]
   6- 10  I5    ---     CDFN      CDFN number, [DRP2007] NNNNN in Simbad
  12- 13  I2    h       RAh       Right ascension (J2000)
  15- 16  I2    min     RAm       Right ascension (J2000)
  18- 22  F5.2  s       RAs       Right ascension (J2000)
      24  A1    ---     DE-       Declination sign (J2000)
  25- 26  I2    deg     DEd       Declination (J2000)
  28- 29  I2    arcmin  DEm       Declination (J2000)
  31- 35  F5.2  arcsec  DEs       Declination (J2000)
  37- 40  F4.2  ---     Pchi      χ2 probability for power-law fit
                               (see section 3 of paper)
  42- 46  F5.2  ---     alpha     IRAC spectral index (f(ν)∝νalpha)
  48- 51  F4.2  ---     z         ?=- Redshift
  53- 56  F4.2  ---     e_z       ? rms uncertainty on z
      58  A1    ---     l_F24um   Limit flag on F24um
  59- 64  F6.1  uJy     F24um     ? 24um flux density
      66  A1    ---     l_F1.4G   Limit flag on F1.4G
  67- 72  F6.1  uJy     F1.4G     1.4GHz flux density
      74  A1    ---     l_FX      Limit flag on FX
  75- 82  E8.3  mW/m2   FX        0.5-8keV X-ray flux
      84  A1    ---     l_logLX   Limit flag on logLX
  85- 88  F4.1  [10-7W] logLX     ?=- X-ray luminosity in 0.5-8keV
  90- 97  E8.3  s       Exp       X-ray exposure time
  99-102  F4.1  arcmin  theta     X-ray off-axis angle
     104  A1    ---     l_q       Limit flag on q
 105-109  F5.2  [-]     q         ?=- Flux ratio, log(F24um/F1.4G)


Byte-by-byte Description of file: table5.dat

   Bytes Format Units   Label    Explanations

   1- 10  E10.4 um      Arp.w    The Arp 220 template wavelength
  12- 21  E10.4 Jy      Arp.F    The Arp 220 template flux density
  23- 32  E10.4 um      IRAS.w   ? The IRAS 17208-0014 template wavelength
  34- 43  E10.4 Jy      IRAS.F   ? The IRAS 17208-0014 template flux density
  45- 54  E10.4 um      Mrk.w    ? The Mrk 273 template wavelength
  56- 65  E10.4 Jy      Mrk.F    ? The Mrk 273 template flux density


History:
    From electronic version of the journal
(End)                  Greg Schwarz [AAS], Patricia Vannier [CDS]    04-Mar-2009