J/MNRAS/462/3285    XQ-100. X-shooter quasar spectra          (Perrotta+, 2016)
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Nature and statistical properties of quasar associated absorption systems in the
XQ-100 Legacy Survey.
    Perrotta S., D'odorico V., Prochaska J.X., Cristiani S., Cupani G.,
    Ellison S., Lopez S., Becker G.D., Berg T.A.M., Christensen L.,
    Denney K.D., Hamann F., Paris I., Vestergaard M., Worseck G.
   <Mon. Not. R. Astron. Soc., 462, 3285-3301 (2016)>
   =2016MNRAS.462.3285P    (SIMBAD/NED BibCode)
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ADC_Keywords: Surveys ; QSOs ; Spectroscopy ; Redshifts
Keywords: galaxies: high-redshift - intergalactic medium -
          quasars: absorption lines

Abstract:
    We statistically study the physical properties of a sample of narrow
    absorption line (NAL) systems looking for empirical evidences to
    distinguish between intrinsic and intervening NALs without taking into
    account any a priori definition or velocity cut-off. We analyse the
    spectra of 100 quasars with 3.5<z_em_<4.5, observed with
    X-shooter/Very Large Telescope in the context of the XQ-100 Legacy
    Survey. We detect an ~8{sigma} excess in the CIV number density
    within 10000km/s of the quasar emission redshift with respect
    to the random occurrence of NALs. This excess does not show a
    dependence on the quasar bolometric luminosity and it is not due to
    the redshift evolution of NALs. It extends far beyond the standard
    5000km/s cut-off traditionally defined for associated absorption
    lines. We propose to modify this definition, extending the threshold
    to 10000km/s when weak absorbers (equivalent width <0.2{AA})
    are also considered. We infer NV is the ion that better traces the
    effects of the quasar ionization field, offering the best statistical
    tool to identify intrinsic systems. Following this criterion, we
    estimate that the fraction of quasars in our sample hosting an
    intrinsic NAL system is 33 per cent. Lastly, we compare the properties
    of the material along the quasar line of sight, derived from our
    sample, with results based on close quasar pairs investigating the
    transverse direction. We find a deficiency of cool gas (traced by C
    II) along the line of sight connected to the quasar host galaxy, in
    contrast with what is observed in the transverse direction.

Description:
    The quasars in our sample have been originally selected and observed
    in a new Legacy Survey, hereafter 'XQ-100', of 100 quasars at
    emission redshift z_em_=3.5-4.5 (ESO Large Programme 189.A-0424).
    The observations have been carried out with X-shooter/VLT (Vernet et
    al., 2011A&A...536A.105V). The released spectra provide a complete
    coverage from the atmospheric cut-off to the NIR with a spectral
    resolution R~6000-9000 depending on wavelength, and a median S/N~30 at
    the continuum level. XQ-100 provides the first large
    intermediate-resolution sample of high-redshift quasars with
    simultaneous rest-frame UV/optical coverage. A full description of the
    target selection, observations, and data reduction process is
    presented by Lopez et al. (2016A&A...594A..91L).

File Summary:
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 FileName      Lrecl  Records   Explanations
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ReadMe            80        .   This file
sources.dat       60      100   XQ-100 targets
table2.dat       132      987   Data for the XQ-100 targets
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Byte-by-byte Description of file: sources.dat
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   Bytes Format Units   Label     Explanations
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   1- 10  A10   ---     Name      Name of the target
  12- 35  A24   ---     OName     Other name
  37- 38  I2    h       RAh       Right ascension (J2000)
  40- 41  I2    min     RAm       Right ascension (J2000)
  43- 47  F5.2  s       RAs       Right ascension (J2000)
      49  A1    ---     DE-       Declination sign (J2000)
  50- 51  I2    deg     DEd       Declination (J2000)
  53- 54  I2    arcmin  DEm       Declination (J2000)
  56- 60  F5.2  arcsec  DEs       Declination (J2000)
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Byte-by-byte Description of file: table2.dat
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   Bytes Format Units    Label     Explanations
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   1- 10  A10   ---      Name      Name of the target
  12- 17  F6.4  ---      zem       Emission redshift of the target
  19- 24  F6.3  10-7W    Lbol      Bolometric luminosity of the target
  26- 30  F5.3  10-7W  e_Lbol      Bolometric luminosity error
  32- 34  A3    ---      RType     Radio type (1)
  36- 40  F5.3  ---      zabs      Redshift of the absorbers (NAL)
  42- 46  F5.2  [cm-2]   logNCIV   CIV 1548 column density
  48- 51  F4.2  [cm-2] e_logNCIV   CIV 1548 column density error
  53- 57  F5.3  0.1nm    EWCIV     CIV 1548 rest-frame equivalent width
  59- 63  F5.3  0.1nm  e_EWCIV     CIV 1548 rest-frame equivalent width error
  65- 69  F5.2  [cm-2]   logNSiIV  ?=0 SiIV 1393 column density
  71- 74  F4.2  [cm-2] e_logNSiIV  ?=0 SiIV 1393 column density error
  76- 80  F5.3  0.1nm    EWSiIV    ?=0 SiIV 1393 rest-frame equivalent width
  82- 86  F5.3  0.1nm  e_EWSiIV    ?=0 SiIV 1393 rest-frame equivalent width
                                    error
  88- 92  F5.2  [cm-2]   logNNV    ?=0 NV 1238 column density
  94- 97  F4.2  [cm-2] e_logNNV    ?=0 NV 1238 column density error
  99-103  F5.3  0.1nm    EWNV      ?=0 NV 1238 rest-frame equivalent width
 105-109  F5.3  0.1nm  e_EWNV      ?=0 NV 1238 rest-frame equivalent width error
 111-115  F5.2  [cm-2]   logNCII   ?=0 CII 1334 column density
 117-120  F4.2  [cm-2] e_logNCII   ?=0 CII 1334 column density error
 122-126  F5.3  0.1nm    EWCII     ?=0 CII 1334 rest-frame equivalent width
 128-132  F5.3  0.1nm  e_EWCII     ?=0 CII 1334 rest-frame equivalent width
                                    error
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Note (1): Radio type as follows:
   RL  = Radio loud QSO
   RQ  = Radio quiet QSO
   not = target without radio information
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History:
    From electronic version of the journal

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(End)                                      Patricia Vannier [CDS]    15-Mar-2018