This database contains information on sources detected with the Einstein Observatory Image Proportional Counter (IPC), assembled for the Einstein Observatory Catalog (EOSCAT) of IPC X-ray Sources (2E) and containing over 4000 unique sources (with 6539 separate detections) which were detected with the IPC at a level of significance greater than 3.5 sigma in the broad band (0.2-3.5 keV). This database also contains the list of 277 sources which are known not to have been included in the Einstein Observatory Source Catalog (flagged by supplement = 'Y' in this database). Those which were not detected during the standard Rev1B processing were typically discovered upon visual inspection of the contour diagrams in the Catalog. Others were detected with Rev1B standard processing but left out of the Catalog because of short exposure times or other reasons listed in the "missed_code" field. 258 of these 277 additional sources have no valid signal to noise ratio (SNR) estimate (values of 0.0), while 3 others have SNR values of 3.2 and 3.3, notice. This IPC database is based on NASA Astrophysics Data System (ADS) tables that were created in 1991 and 1993 and were themselves derived from tables provided by Dr. D. E. Harris of the Center for Astrophysics at Harvard-Smithsonian. The HEASARC has a similar catalog in its database called EINSTEIN2E which comprises a more recent version of the IPC source list as archived at the NASA Astronomical Data Center (ADC) and the Center for Astronomical Data at Strasbourg (CDS). EINSTEIN2E has 868 fewer detections than the IPC catalog, notice, for reasons that the HEASARC is unsure of, but that may imply that some of the detections in IPC are not reliable. We have retained the IPC database for reasons of completeness, but caution that detections listed here which have no counterpart in the EINSTEIN2E Catalog should be treated with caution. This IPC database was recreated by the HEASARC in December 2000 to replace a previous version in which we discovered some transcription errors. It is based on NASA Astrophysics Data System (ADS) tables that were created in 1991 and 1993 and were themselves derived from tables provided by Dr. D. E. Harris of the Center for Astrophysics at Harvard-Smithsonian:

 The Einstein IPC Source List From EOSCAT (ADS Creation Date: 26-Dec-1990; ADS Last Revision Date: 04-Nov-1993), D.E. Harris, CfA The EOSCAT List of Missed IPC Sources (ADS Creation Date: 26-Oct-1990; ADS Last Revision Date: 17-Sep-1991), D.E. Harris, CfA 

This is a service provided by NASA HEASARC .

The Einstein Extended Source Survey (EXSS) catalog contains a list of extended sources found in the Einstein Observatory Imaging Proportional Counter (IPC) Database. The source detection algorithm was substantially improved over that used for the Einstein Medium Sensitivity Survey (EMSS). Sources were searched for using circular apertures with variable radii of up to 6.1 arcminutes. Criteria were constructed so as to ascertain which of the detections were truly diffuse and which of the sizes best approximated each detection. Using these criteria, a catalog of 1325 extended source candidates at high galactic latitude (more than 20 degrees from the Galactic Equator) was produced. Cross-correlating this list with existing source catalogs yielded a reasonably comprehensive set of identifications for the sources in this list: over 400 were identified with known clusters of galaxies, while other objects were identified with galaxies, supernova remnants (SNR), active galactic nuclei (AGN), and stars. Whereas galaxies and SNR are often truly extended objects, AGN and stars can appear as extended ojects as a consequence of their soft X-ray spectra coupled with the broad point-spread function of the IPC at low energies. A total of 321 objects remain completely unidentified. Some of these may be heretofore uncatalogued clusters and groups of galaxies at moderate redshifts. The data used to construct this database table were obtained from the first author's Web site on 12 December 1997. This is a service provided by NASA HEASARC .

This database contains the 70 `discrete' (i.e., more compact than a few arc minutes) Einstein IPC X-ray sources in the direction of the Small Magellanic Cloud (SMC) that are tabulated in Table 2A of Wang & Wu (1992, ApJS, 78, 391). For full details about the data processing and selection criteria used to create the original source catalog, the above reference should be consulted. This is a service provided by NASA HEASARC .

This database table contains primary HRI source parameters for the 202 HRI sources found in the Einstein Deep Survey. The Einstein Deep Survey (EDS) program consisted of very deep X-ray exposures in selected regions of the sky at high galactic latitude. The main purposes of the survey are to investigate the nature of the extragalactic X-ray background through direct source counts at very low flux levels and to study the nature of the very faint X-ray sources which comprise a significant fraction, if not all, of the soft X-ray background. This is a service provided by NASA HEASARC .

This table contains results from an all-sky survey, performed by the Imager on-Board the INTEGRAL Satellite (IBIS) telescope on board the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) observatory over 11 years of operation, using data acquired at energies above 100 keV. The catalog of detected sources includes 132 objects. The statistical sample detected on the time-averaged 100-150 keV map at a significance above 5 sigma contains 88 sources: 28 active galactic nuclei (AGNs), 38 low-mass X-ray binaries (LMXBs), 10 high-mass X-ray binaries (HMXBs) and 12 rotation-powered young X-ray pulsars. The catalog also includes 15 persistent sources, which were registered at a significance 4 sigma <= S/N < 5 sigma, where S/N is the signal-to-noise ratio, but at the same time were firmly detected (>= 12 sigma) in the lower 17-60 keV energy band. All registered sources are known X-ray emitters, which means that the catalog has 100% purity in this respect. Additionally, 29 catalogued sources were detected significantly in different time slices of the survey. In the reference paper presenting the results of this survey, the authors present a hardness ratio for Galactic and extragalactic sources, an LMXB longitudinal asymmetry, and a number-flux relation for non-blazar AGNs. At higher energies, in the 150-300 keV energy band, 25 sources have been detected with S/N >= 5 sigma, including seven AGNs, 13 LMXBs, three HMXBs and two rotation-powered pulsars. Among LMXBs and HMXBs, the authors identified 12 black hole candidates (BHCs) and four neutron star (NS) binaries. For this hard X-ray survey, the authors utilized all publicly available INTEGRAL data acquired by the IBIS telescope between 2002 December and 2014 January (INTEGRAL spacecraft revolutions 26 - 1377). The survey also contains private data from the M82 deep field (PI: Sazonov) and scanning observations of the Galactic Center (PI: Krivonos) and Puppis region (PI: Tsygankov). The survey sky coverage as a function of a 5-sigma limiting flux is shown in Fig. 2 of the reference paper. The peak sensitivity of the survey is about 2 mCrab (8 x 10^-12 erg s^-1 cm^-2 in the 100-150 keV energy band). The survey covers ~10% of the sky down to a flux limit of 3.7 mCrab (1.5 x 10^-11 erg s^-1 cm^-2) and 90% of the sky down to 25 mCrab (10^-10 erg s^-1 cm^-2). The catalog has been compiled from sources passed through detection conditions in the reference 100-150 keV energy band on time-average sky maps (Section 2.1 of the reference paper) and maps built over different time periods (Section 2.2 ibid.). For all 132 sources, the time-averaged fluxes are given, even for those sources which were not detected therein. For some variable sources and for sources which were only detected in certain time periods, the fluxes measured in the specified time intervals are also given. Thus, this catalog has 50 additional rows for such entries, giving it a total size of 182 rows. This table was created by the HEASARC in November 2016 based on the electronic version of Table 2 from the reference paper which was obtained from the CDS (their catalog J/MNRAS/448/3766 file table2.dat). This is a service provided by NASA HEASARC .

The Einstein High Resolution Imager (HRI) consisted of a micro-channel plate. This database table has been generated at the EXOSAT observatory by automatically processing all the HRI images. Both the images and detected sources are available. This catalog has not been cleaned or checked. Users should beware of two possible problems: (1) spurious detections caused by extended sources have not been checked, and (2) there may be a one-pixel offset in some positions. For HRI images, one pixel is one arcsecond. (The images are rebinned from the original 0.5 arcseconds.) This is a service provided by NASA HEASARC .

This database table contains the list of sources detected in the IPC Slew Survey. It was created in March 1992 and contains 819 entries. The original IPC Slew Survey source list was released on CD-ROM and contained 1067 sources. The list was updated in 1991 to remedy a software bug which omitted a thin slice of RA near 24h; the bug fix yielded 8 additional sources, to bring the total to 1075. The list, however, was found to contain a large fraction (10 to 15 percent) of unreliable sources, especially those sources with <= 5 photons. The unreliable sources were rejected in producing the latest version of the source list, so that it now has an estimated false source rate of only 2 percent, and contains 256 fewer sources than the previous version. The previous version of the source list, with 1075 sources, has been retained in a database called OLDIPCSLEW. The HEASARC implemented this database table in March 1992. This is a service provided by NASA HEASARC .

This table is the Einstein Solid State Spectrometer catalog of observations and data products. It incorporates the most recent ice model that is described in the article on the SSS calibration by Christian, Swank, and White that appeared in the HEASARC journal, Legacy, No. 1. Also available as "associated" data products are the quasi-simultaneous observations made by the Einstein Monitor Proportional Counter. There are 634 distinct SSS observations in this database, 95% of which have associated MPC data products. The remaining SSS observations cover time intervals in which all MPC data was flagged as bad by the pCHIP program that was used to generate the MPC spectra and lightcurves. This is a service provided by NASA HEASARC .