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J/MNRAS/399/728     UV-bright sources behind M31 halo        (Fittingoff+, 2009)
A survey of ultraviolet-bright sources behind the halo of M31.
    Fittingoff A., Prochaska J.X., Kalirai J.S., Strader J., Guhathakurta P.,
    Kaplan K.F.
   <Mon. Not. R. Astron. Soc., 399, 728-736 (2009)>
   =2009MNRAS.399..728F
ADC_Keywords: Galaxies, nearby ; Ultraviolet ; QSOs

Keywords: galaxies: haloes - galaxies: individual: M31 -
          quasars: absorption lines

Abstract:
    We have performed a wide-area ultraviolet (UV) imaging survey using
    the GALaxy Evolution eXplorer to search for bright, point-like UV
    sources behind M31's extended halo. Our survey consisted of 46
    pointings covering an effective area of ∼50deg2, in both the far-UV
    and near-UV channels. We combined these data with optical R-band
    observations acquired with the WIYN Mosaic-1 imager on the Kitt Peak
    National Observatory 0.9-m WIYN telescope. An analysis of the
    brightness and colours of sources matched between our photometric
    catalogues yielded ∼100 UV-bright quasar candidates. We have
    obtained discovery spectra for 76 of these targets with the Kast
    spectrometer on the Lick 3-m telescope and confirmed 30 active
    galactic nuclei and quasars, 29 galaxies at z>0.02 including several
    early-type systems, 16 Galactic stars (hot main-sequence stars) and
    one featureless source previously identified as a BL Lac object.
    Future UV spectroscopy of the brightest targets with the Cosmic
    Origins Spectrograph on the Hubble Space Telescope will enable a
    systematic search for diffuse gas in the extended halo of M31.

Description:
    We were awarded a total of 46 pointings during Cycle 2 (PI: Prochaska;
    ID=033) of the GALEX mission to image a portion of M31's outer halo.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table2.dat        97    98628   Photometry summary of GALEX/NUV-detected sources
                              in the halo of M31.
table4.dat        65       75   Lick/KAST spectroscopy of QSO candidates
table5.dat        57       60   UV bright, extragalactic sources behind M31


See also:
   J/ApJS/173/643 : GALEX UV photometry of M31 Globular Clusters (Rey+, 2007)


Byte-by-byte Description of file: table2.dat

   Bytes Format Units   Label   Explanations

   1-  5  I5    ---     Seq     Sequential number
   7- 11  A5    ---     ---     [GALEX]
  13- 31  A19   ---     GALEX   GALEX name (JHHMMSS.ss+DDMMSS.s),
                                <[FPK2009] GALEX JHHMMSS.ss+DDMMSS.s> in Simbad
  33- 34  I2    h       RAh     GALEX right ascension (J2000)
  36- 37  I2    min     RAm     GALEX right ascension (J2000)
  39- 43  F5.2  s       RAs     GALEX right ascension (J2000)
      45  A1    ---     DE-     Declination sign (J2000)
  46- 47  I2    deg     DEd     Declination (J2000)
  49- 50  I2    arcmin  DEm     Declination (J2000)
  52- 56  F5.2  arcsec  DEs     Declination (J2000)
  57- 61  F5.2  mag     FUV     ?=99.99 GALEX/FUV far-UV magnitude (1)
  63- 67  F5.2  mag     e_FUV   ?=-1.00 rms uncertainty on FUV (1)
  69- 73  F5.2  mag     NUV     ?=99.99 GALEX/NUV near-UV magnitude (2)
  75- 78  F4.2  mag     e_NUV   ?=-1.00 rms uncertainty on NUV (2)
  80- 84  F5.2  mag     Rmag    ?=99.99 R magnitude from KPNO photometry (3)
  86- 90  F5.2  mag     e_Rmag  ? rms uncertainty on Rmag
  92- 95  F4.2  ---     s/g     Star/galaxy classifier calculated by
                                 SExtractor on the NUV photometry (4)
      97  A1    ---     Q?      [Y/N] Quasar candidates picked based on
                                 colour relations between UV and R (5)

Note (1): NUV extractions with no FUV match have FUV values of 99.99
     and an error of -1. GALEX magnitudes are in AB system
Note (2): For NUV extractions where KPNO imaging exists but no source was
     detected, we report a value of 99.99. For NUV extractions where no
     KPNO imaging exists, we report no values.
Note (3): R-band magnitudes from KPNO photometry are reported for the NUV
     extraction that are matched to within a 2 arcsec radius of a KPNO
     source.
Note (4): Values near unity indicate a stellar-like PSF

Note (5): The criteria used were 0.5 <FUV-NUV<2, NUV-R<2  and  NUV<21.



Byte-by-byte Description of file: table4.dat

   Bytes Format Units   Label     Explanations

   1- 14  A14   ---     Name      Name (JHHMMSS+DDMMSS),
                                  <[FPK2009] JHHMMSS+DDMMSS> in Simbad
  16- 17  I2    h       RAh       GALEX right ascension (J2000)
  19- 20  I2    min     RAm       GALEX right ascension (J2000)
  22- 23  I2    s       RAs       GALEX right ascension (J2000)
      25  A1    ---     DE-       Declination sign (J2000)
  26- 27  I2    deg     DEd       Declination (J2000)
  29- 30  I2    arcmin  DEm       Declination (J2000)
  32- 33  I2    arcsec  DEs       Declination (J2000)
  35- 44  A10 "DD/MM/YYYY" Date   Observation date
  46- 49  I4    s       expT      Exposure time
  51- 60  A10 "DD/MM/YYYY" Date2  Second observation date
  62- 65  I4    s       expT2     ? Exposure time for second observation


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

   Bytes Format Units   Label     Explanations

       1  A1    ---     Type      [AG] AGN (BAL) or Galaxy (NEL) (1)
   3- 16  A14   ---     Name      Name (JHHMMSS+DDMMSS),
                                  <[FPK2009] JHHMMSS+DDMMSS> in Simbad
  18- 19  I2    h       RAh       GALEX right ascension (J2000)
  21- 22  I2    min     RAm       GALEX right ascension (J2000)
  24- 25  I2    s       RAs       GALEX right ascension (J2000)
      27  A1    ---     DE-       Declination sign (J2000)
  28- 29  I2    deg     DEd       Declination (J2000)
  31- 32  I2    arcmin  DEm       Declination (J2000)
  34- 35  I2    arcsec  DEs       Declination (J2000)
  37- 39  I3    kpc     rho       Impact parameter from the centre of M31 (2)
  41- 45  F5.2  mag     FUV       ?=99.99 Far UV magnitude (in AB system)
  47- 51  F5.2  mag     NUV       ?=99.99 Narrow UV magnitude (in AB system)
  53- 57  F5.3  ---     z         Redshift

Note (1): Type as follows:
      A = AGN (broad emission lines)
      G = Galaxies (narrow emission lines)
Note (2): Impact parameter from the centre of M31, taken to be
     00:42:44.3+41:16:09 (J2000), for an assumed distance of 783kpc.


History:
    From electronic version of the journal
(End)                                      Patricia Vannier [CDS]    02-Aug-2010