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J/ApJ/724/1389       Mapping the diffuse UV sky with GALEX       (Murthy+, 2010)
Mapping the diffuse ultraviolet sky with the Galaxy Evolution Explorer.
    Murthy J., Henry R.C., Sujatha N.V.
   <Astrophys. J., 724, 1389-1395 (2010)>
   =2010ApJ...724.1389M
ADC_Keywords: Interstellar medium ; Surveys ; Ultraviolet

Mission_Name: GALEX

Keywords: diffuse radiation - dust, extinction - surveys - ultraviolet: ISM


Abstract:
    We present a map of the diffuse ultraviolet cosmic background in two
    wavelength bands (FUV: 1530Å and NUV: 2310Å) over almost 75% of
    the sky using archival data from the Galaxy Evolution Explorer (GALEX)
    mission. Most of the diffuse flux is due to dust-scattered starlight
    and follows a cosecant law with slopes of 545 photons/cm2/s/sr/Å
    and 433 photons/cm2/s/sr/Å in the FUV and NUV bands,
    respectively. There is a strong correlation with the 100um Infrared
    Astronomy Satellite (IRAS) flux with an average UV/IR ratio of
    300 photons/cm2/s/sr/Å/(MJy/sr) in the FUV band and that of
    220 photons/cm2/s/sr/Å/(MJy/sr) in the NUV band but with
    significant variations over the sky. In addition to the large-scale
    distribution of the diffuse light, we note a number of individual
    features including bright spots around the hot stars Spica and
    Achernar.

Description:
    The launch of the Galaxy Evolution Explorer (GALEX) in 2003 provided a
    new platform for diffuse UV observations. In the 7 years since its
    launch, GALEX has obtained over 30000 observations covering 75% of the
    sky in two ultraviolet bands (far-ultraviolet, FUV: 1350-1750Å and
    near-ultraviolet, NUV: 1750-2850Å). The GALEX instrument consists
    of a Ritchey-Chretien telescope with a diameter of 50cm for the
    primary mirror. Light from the sky is separated by a dichroic onto two
    detectors (FUV and NUV) with a spatial resolution of 3"-5" over a
    1.25° field of view.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        45    31902   Diffuse flux observed by GALEX


See also:
 II/114 : UV Interstellar Extinction (Savage+ 1985)
 J/ApJ/741/79   : The Spitzer-SDSS-GALEX Spectroscopic Survey (O'Dowd+, 2011)
 J/ApJ/718/L141 : FUV diffuse emission from the LMC (Pradhan+, 2010)
 J/A+AS/127/1   : 1997 reference of diffuse night sky brightness (Leinert+ 1998)


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

   Bytes Format Units   Label     Explanations

   1-  6  F6.2  deg     GLON      Galactic longitude
   8- 13  F6.2  deg     GLAT      Galactic latitude
  15- 21  F7.2 10+5/m2/s/sr/nm TFUV  Total FUV band flux (1)
  23- 29  F7.2 10+5/m2/s/sr/nm TNUV  Total NUV band flux (1)
  31- 37  F7.2 10+5/m2/s/sr/nm FUV  FUV band (1530Å) (1)
  39- 45  F7.2 10+5/m2/s/sr/nm NUV  NUV band (2310Å) (1)

Note (1): total fluxes include the airglow and zodiacal light.
     In units of ph/cm2/s/sr/Angstrom.


History:
    From electronic version of the journal
(End)                 Greg Schwarz [AAS], Emmanuelle Perret [CDS]    06-Aug-2012