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J/ApJ/640/579      Near-infrared spectra of 27 SDSS quasars     (Glikman+, 2006)
A near-infrared spectral template for quasars.
    Glikman E., Helfand D.J., White R.L.
   <Astrophys. J., 640, 579-591 (2006)>
   =2006ApJ...640..579G
ADC_Keywords: QSOs ; Spectra, infrared

Keywords: quasars: emission lines - quasars: general


Abstract:
    We present a near-infrared quasar composite spectrum spanning the
    wavelength range 0.58-3.5um. The spectrum has been constructed from
    observations of 27 quasars obtained at the NASA IRTF telescope and
    satisfying the criteria Ks<14.5 and Mi←23; the redshift range is
    0.118<z<0.418. The signal-to-noise ratio is moderate, reaching a
    maximum of 150 between 1.6 and 1.9um. While a power-law fit to the
    continuum of the composite spectrum requires two breaks, a single
    power-law slope of alpha=-0.92 plus a 1260K blackbody provides an
    excellent description of the spectrum from Hα to 3.5um, strongly
    suggesting the presence of significant quantities of hot dust in this
    blue-selected quasar sample. We measure intensities and line widths
    for 10 lines, finding that the Paschen line ratios rule out case B
    recombination. We compute K-corrections for the J, H, K, and Spitzer
    3.6um bands, which will be useful in analyzing observations of quasars
    up to z=10.

Description:
    We obtained near-infrared spectra for 27 of the quasars. All spectra
    but one were obtained at the NASA Infrared Telescope Facility (IRTF),
    a 3.0m telescope optimized for infrared observations on the summit of
    Mauna Kea, Hawaii.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
list.dat          74       27   List of studied QSOs
table3.dat        31     7740   Composite quasar spectrum, arithmetic and
                              geometric means
table7.dat        31    10944   Optical-to-infrared composite quasar spectrum,
                              arithmetic and geometric means
table8.dat        31      100   Quasar K-corrections
sp/*              33       27   Individual spectra


See also:
    VII/252 : SDSS-DR5 quasar catalog (Schneider+, 2007)
    http://www.sdss.org : SDSS Home Page


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

   Bytes Format Units   Label     Explanations

   1-  4  A4    ---     ---       [SDSS]
   6- 24  A19   ---     SDSS      SDSS name (JHHMMSS.ss+DDMMSS.s)
  26- 27  I2    h       RAh       Right ascension (J2000)
  29- 30  I2    min     RAm       Right ascension (J2000)
  32- 36  F5.2  s       RAs       Right ascension (J2000)
      38  A1    ---     DE-       Declination sign (J2000)
  39- 40  I2    deg     DEd       Declination (J2000)
  42- 43  I2    arcmin  DEm       Declination (J2000)
  45- 48  F4.1  arcsec  DEs       Declination (J2000)
  52- 74  A23   ---     FileName  Name of the spectra file in sp subdirectory


Byte-by-byte Description of file: table[37].dat

   Bytes Format Units   Label     Explanations

   1-  7  F7.1  0.1nm   Lambda    Wavelength in Angstroms
   9- 15  F7.4  ---     Flux      Arithmetic mean flux in arbitrary units
  17- 23  F7.4  ---     e_Flux    Error in Flux
  25- 31  F7.4  ---     GFlux     Geometric mean flux in arbitrary units


Byte-by-byte Description of file: table8.dat

   Bytes Format Units   Label     Explanations

   1-  4  F4.1  ---     z         Redshift
   6- 10  F5.3  mag     Kc(J)     ? 2MASS J band K-correction
  12- 17  F6.3  mag     Kc(H)     ? 2MASS H band K-correction
  19- 24  F6.3  mag     Kc(K)     ? 2MASS KS band K-correction
  26- 31  F6.3  mag     Kc(3.6)   Spitzer IRAC 3.6 micron band K-correction


Byte-by-byte Description of file: sp/*

   Bytes Format Units   Label     Explanations

   1-  8  F8.6  um      Lambda    Wavelength
  10- 21  E12.5 ---     Flux      Flux in arbitrary units
  23- 33  E11.5 ---     e_Flux    Error in Flux in arbitrary units


History:
    From electronic version of the journal
(End)                  Greg Schwarz [AAS], Patricia Vannier [CDS]    26-Sep-2008