Contents

• Contents
• INTRODUCTION
  • The Ginga Mission
  • The Ginga Databases
• PIPELINE PROCESSING
  • Data Selection within Sortac
  • Gain
  • Data Selection Post-sortac
  • Background Estimation
  • Attitude Correction
  • Spectral Fits
  • Light Curves
• QUALITY FLAG
• REFERENCES
• FIELDS
• Table and Figures
  • Table 1 Data Products.
  • Table 2 Data Selection Criteria.
  • Table 3 Quality Assessment.
• FIGURE CAPTIONS

ABSTRACT
The Japanese satellite Ginga made over 1000 observations of celestial X-ray sources with the LAC collimated proportional counter during 1987-91. Its large area,  cm², and broad energy range, 1.5-37 keV, made the Ginga LAC an unique and popular X-ray detector.

In this paper we describe the automatic processing of the Ginga LAC MPC1 data to produce the databases. Over 80% of Ginga observations were made in this mode, which provided full spectral resolution together with 16 second time resolution. We describe the production of a series of universal background models which were used to background subtract both source and off-source (nominally empty) fields. Some datasets were background-subtracted using a local method which made use of contemporaneous background observations where these were available. We describe the data selection and the various quality checks that have been made. The results of the processing are available in the GINGALAC and GINGABGD databases within the Leicester data archive service (http://ledas-www.star.le.ac.uk/ginga/ginga.html). They include count rates, hardness ratios, a variability measure and the results of limited spectral fitting. A uniformly applied quality flag is also provided. There are product files associated with each database entry. These files conform to the OGIP FITS conventions where applicable. They include data cubes, spectra and light curves, and also plots summarising the quality of the observation and the results of the spectral fits.

The data in the GINGALAC and GINGABGD databases will allow the less expert user to benefit from the Ginga observations. These have not previously been widely available, being in a Ginga-specific format, but are made available for the more experienced user in the GINGAFRF database at the same location.

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