The Einstein Observatory Imaging Proportional Counter Slew Survey V1.1

Description

This CD is the first publicly available version of the Einstein Imaging Proportional Counter (IPC) Slew Survey. The IPC was one of two imaging detectors onboard the Einstein Observatory, which was a satellite-based imaging X-ray telescope operating over the 0.2-3.5 keV energy range. Einstein was in operation from November, 1978 to April, 1981, nominally in a pointed mode. The Slew Survey was constructed wholly from data acquired when the IPC was slewing between one pointed observation and the next. The CD-ROM contains source lists, data, and relevant analysis software. The Slew Survey has a total exposure of ~1 million s and covers ~80% of the sky. Typical survey exposures of 12 s cover 50% of sky. Some regions of the sky have especially favorable coverage. For example, the Cygnus Loop, which has ~150 s exposure, produces an image with over 100,000 photons. The Slew Survey currently contains 1083 sources, of which more than half have been identified with objects in known catalogs. The individual slews have been co-added into sky bins of 6.5O x 6.5O degrees, to simplify computation. A detection algorithm were then applied and compared to known sources in catalogs. The data products included on the CD follow the same binning scheme and will allow the user to perform a similar analysis. The disk contains: 1303 FITS-A3D files, containing Slew Survey photon event data; a catalog of all detected sources, with many optical counter-parts listed; documentation about the images and their use; auxiliary data files (for aspect solution and timing gap records); and software to extract count rates at user-selected sky positions. The sky bin data files on these disks conform to the new n-dimensional table extension (``A3DTABLE'') of the Flexible Image Transport System (FITS). The CDs themselves have been mastered according to the International Organization for Standardization (ISO) Standard 9660, Level 1.