Einstein EMSS Survey

At present over 96% of the 835 X-ray sources have been successfully identified in the following proportions: active galactic nuclei (QSO's, quasars and Seyfert), 51.1%; BL Lacertae objects, 4.3%; clusters of galaxies, 12.2%; normal galaxies, 2.1%; cooling flow galaxies, 0.6%; Galactic stars 25.8%; and unidentified, 3.9%. Most of the individual optical counterparts are previously unknown objects and so constitute large statistical samples independent of previously selection methods.

The contents of the table is described below. The sky coverage computed for a specific assumed source spectrum is also given under "Additional Information" below. For further details please see the published articles: Gioia et al. 1990, Stocke et al. 1991.

Additional Information: The EMSS sky coverage. ---------------------- This sky coverage has been produced using the counts in the standard detection algorithm and assuming a power law spectrum with energy index = 1 and the measured Galactic hydrogen column density in the direction of each IPC pointing. We caution the user that this sky coverage is not appropriate for computation of functions like logN(>S)-logS, or Luminosity Functions of resolved sources, like clusters of galaxies or "normal" galaxies, nor of stars.

The fluxes for these objects have been calculated either using extended counts, when appropriate, and/or different assumptions for the incident spectrum (see below). Limiting Sensitivity Area Covered (erg/cm**2/s) (sq. deg) 5.08E-14 0.09 6.09E-14 0.72 7.31E-14 2.54 8.78E-14 6.37 1.05E-13 15.1 1.26E-13 29.4 1.52E-13 55.2 1.82E-13 94.2 2.18E-13 139.4 2.62E-13 191.6 3.14E-13 249.5 3.77E-13 319.1 4.53E-13 402.0 5.43E-13 497.0 6.52E-13 582.9 7.83E-13 657.7 9.39E-13 711.8 1.13E-12 743.7 1.35E-12 762.7 1.62E-12 771.9 1.95E-12 775.7 2.34E-12 777.4 2.80E-12 777.9 3.36E-12 778.1 --------------------------------------------------------------------------------