EXOSAT Gas Scintillation Proportional Counter


A schematic view of the GSPC detector artist concept of EXOSAT in space

Data products

The available products for the Gas Scintillator Proportional Counter (GSPC) detector are spectra, response matrices and lightcurves. Spectra and lightcurves were originally created, in binary format, at the EXOSAT Observatory during the post operational phase. HEASARC converted all EXOSAT GSPC products in FITS and generated for each spectrum a response matrix, as well in FITS format. GSPC data products were obtained only for those observations where the source ME count rate was in excess of 5 count/s per half. Sources with lower ME count rates typically do not have sufficient signal-to-noise to justify in mean a GSPC analysis. At HEASARC the products, in FITS format, are available from EXOSAT gspc FTP area on HEASARC's archive computer.
  • Lightcurves : Background subtracted lightcurves were obtained for each source (with sufficient signal-to-noise) in two bands, 2-8 keV and 8-15 keV, with a time resolution of 8 seconds. The GSPC lightcurves in FITS format make use of the FITS binary table extension (BINTABLE). The specific FITS layout of the data is described in the Legacy 3, 32. The total number of EXOSAT GSPC lightcurves is 1214. HEASARC generated also GIF files (available from the EXOSAT gspc FTP area) which show the lightcurves in the two energy band.

  • Spectra and Response Matrices : For each source there is an average background subtracted spectrum. The average spectrum for burst sources does not include burst events. The GSPC spectra and response matrices in FITS format make use of the FITS binary table extension (BINTABLE). The specific FITS layout for spectra and response matrices are described in the Legacy 2, 65 and Legacy 2, 51 respectivaly. The total number of EXOSAT GSPC spectra and response matrices is 1330. HEASARC generated also GIF files (available from the EXOSAT gspc FTP area) which show the spectrum convolved with the response matrix.
A CDROM (vol2) containing all the lightcurves, spectra and response matrices in FITS and GIF format is available and was first distributed at the 188th AAS Meeting (9-13 June 1996 Madison, Wisconsin).

Products naming convention The GS product file names are a 6-character strings, a letter followed by a 5-digit number, generated automatically by the computer, based on the start time of the observation. The first character, which identifies the product type, has a different convention for the 3 experiments (LE+CMA, ME and GS), but within an experiment different products associated with the same observation share the 5 digit number. The GS spectra have `s' as the first character, instead `c' and `d' are used for the lightcurves obtained in different energy bands.

Software

  • Products : XSPEC and XRONOS software packages are useful for analysis of the FITS spectra and lightcurves respectivaly. The FTOOLS package provides also a number of programs to manipulate the FITS file. The GIF files can be viewed on UNIX and VMS with the package xv, under DOS with ColorView and under MacOS with Giffer.

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Last modified: Thursday, 26-Jun-2003 13:48:33 EDT