- ID:
- ivo://nasa.heasarc/ipcultsoft
- Title:
- Einstein IPC Ultrasoft Sources Catalog
- Short Name:
- IPCUltrasoft
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- A survey of the entire Einstein IPC database (a total of 5934 sources) has been carried out in order to select objects with strong components of ultrasoft X-ray emission (i.e., emission below 0.5 keV). The selection criteria were based on ratios of counts within three broad energy bands (i.e., X-ray "colors"). A total of 516 objects have been selected, with 202 (39%) having been identified through correlations with other databases. Of the currently identified objects, 45% are active galactic nuclei, 28% are stellar objects, 6% are "normal" galaxies and galaxy clusters, and the remaining 21% are "nonstellar" Galactic objects such as cataclysmic variables, pulsars, and white dwarfs. The selection of sources for this survey was based on the analysis of counts in three broad energy bands defined as C1=0.16-0.56 keV, C2=0.56-1.08 keV, and C3= 1.08-3.5 keV. Ratios of these three bands constituted X-ray 'colors' which in turn were used to estimate the shape of the spectrum over the IPC bandpass. Based on models of X-ray spectra folded through the IPC response function, the following criteria were determined for the selection of ultrasoft sources: C1>0 and R1=C2/C1<0.36. These criteria guarantee an intrinsically soft X-ray spectrum that can be modeled by blackbody temperatures kT<50 keV, power-law spectral indices of >=2, or thermal plasma temperatures T<1 MK (million K). Details of the data analysis can be found in the Thompson et al. (1998) reference. This database was created by the HEASARC in April 1999 based on tables provided by the catalog authors to the CDS/ADC. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/ipcunscrnd
- Title:
- Einstein IPC Unscreened Photon Event List
- Short Name:
- IPCUNSCRND
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table gives access to the IPC unscreened data set, which includes files in the event list format together with auxiliary files. This data set was generated by the Einstein Data Center and delivered to the HEASARC on CD-ROM. The Einstein Observatory (HEAO-2) operated from November 1978 to April 1981. Einstein carried the first fully imaging X-ray telescope in space and operated in pointing mode. The Imaging Proportional Counter had a bandpass of 0.2-3.5 keV and was one of two detectors onboard used for imaging. During the Einstein lifetime more than 4000 targets were observed with the IPC. This database table was last updated by the HEASARC in August 2005. Galactic coordinates were added and some parameters were renamed to adhere to the HEASARC's current parameter naming conventions. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ipclxlbol
- Title:
- EinsteinLX&LBLValuesforIPCOStars
- Short Name:
- IPCLXLBOL
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Soft X-ray (0.2 - 3.5 keV) measurements for all normal, massive, o-type stars surveyed with the Einstein Observatory are presented as a catalog containing 89 detections and 176 upper bounds, together with a detailed discussion of the reduction process. Values of L[x]/L[bol] listed for most stars, range from 10e-5.44 to 10e-7.35; l[x] spans more than 3 orders of magnitude, ranging from 1.5 x 10e31 to 2 x 10e34 ergs se-1. It is noted that at least 30% of o-type stars are variable in X-rays, but that there is little evidence for new objects whose X-ray emission might be significantly enhanced by accretion processes onto a neutron star. For further information, please contact the HEASARC. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/mpcraw
- Title:
- Einstein MPC Raw Data
- Short Name:
- MPCRAW
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Einstein Observatory (also known as HEAO-2 or HEAO-B) was operational from 1978 November 13 until 1981 April 25 when the Einstein attitude control system failed. The Monitor Proportional Counter (MPC) was a non-focal plane instrument that monitored the 1 to 20 keV X-ray flux of the source(s) being observed simultaneously by the operational focal plane instrument. The MPC was a collimated proportional counter filled with argon and carbon dioxide. It had a circular field of view, 1.5 degrees in diameter (FWHM), which was co-aligned with the telescope. A 1.5 mil Be window sealed the gas in the detector and shielded the detector from ultraviolet radiation. The active area of the MPC was 667 square cm. The MPC obtained useful data from 1978 November 19 until 1981 April 17, with the exception of a 3-month period from 1980 Aug 27 to 1980 Dec 08 when operation was intermittent, due to Einstein Observatory attitude control problems. The characteristics of the MPC have been described in detail by Gaillardetz et al.(1979) and by Grindlay et al. (1980). One duplicate entry was removed from the HEASARC implementation of this catalog in June 2019. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/eingalclus
- Title:
- Einstein Observatory Clusters of Galaxies Catalog
- Short Name:
- Einstein/Clus
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Einstein Observatory Clusters of Galaxies Catalog presents the X-ray characteristics of a sample of 368 clusters of galaxies with redshifts less than 0.2 which were observed with the Einstein Imaging Proportional Counter (IPC). For each cluster, the authors measured the 0.5 - 4.5 keV counting rate and computed the 0.5 - 4.5 keV source luminosity, as well as the bolometric luminosity within fixed metric radii. They detected 85% of Abell clusters with z < 0.1, demonstrating that the large majority of these optically selected clusters are not the results of chance superpositions. For 163 clusters, they measured their X-ray surface brightness profiles and determined their core radii. For about 230 clusters, they then used either their measured core radii and beta values, or mean values derived for this sample, to measure central gas densities and gas masses. They used estimated or measured cluster gas temperatures, along with the derived gas-density profiles, to estimate total cluster masses, under the assumptions that the gas is isothermal and in hydrostatic equilibrium. This table was created by the HEASARC in June 2005 based on the merger of CDS tables J/ApJ/511/65/table3.dat and table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/einstein2e
- Title:
- Einstein Observatory 2E Catalog of IPC X-Ray Sources
- Short Name:
- Einstein2E
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This is the Einstein Observatory 2E Catalog of Imaging Proportional Counter (IPC) X-Ray Sources which was created by the HEASARC from the CDS Catalog IX/13. This latter catalog was prepared by the CDS in October 1996 based on the Einline version. It is similar to the HEASARC's IPC source catalog which the HEASARC created in the early 1990s directly based on Einstein Observatory Source Catalog tables obtained from the then-extant Astrophysics Data System distributed data archive. The IPC Catalog contains 6816 entries compared to 5948 entries in this catalog, notice. This catalog contains sources with signal-to-noise values of 3.5 and greater from Einstein IPC observations. Note that a single source may have more than one entry in this catalog. This catalog was created by the HEASARC in November 2000 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/IX/13">CDS Catalog IX/13</a> file 2e.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sssraw
- Title:
- Einstein SSS and MPC Raw Data
- Short Name:
- SSSRAW
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Einstein Observatory (also known as HEAO-2 or HEAO-B) was operational from 1978 November 13 until 1981 April 25 when the attitude control system failed. The Solid State Spectrometer (SSS) was operated intermittently between 1978 December 1 and 1979 October 22. However, the cryogen cooling for the detector was used up by about 2 weeks prior to the date of this last observation, so that the last reliable observation of the SSS is considered to have occurred on 1979 October 03. The SSSRAW database accesses the raw SSS data (and the associated monitoring proportional counter, MPC, data), restored in FITS format at HEASARC from the original machine dependent format data set. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sss
- Title:
- Einstein SSS Spectra and Lightcurves
- Short Name:
- SSS
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/einopslgal
- Title:
- Einstein Survey of Optically Selected Galaxies
- Short Name:
- Einstein/OGal
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Einstein Survey of Optically Selected Galaxies contains the results of a complete Einstein Imaging Proportional Counter (IPC) X-ray survey of optically-selected galaxies from the Shapley-Ames (S-A) Catalog (CDS Catalog <VII/112>), the Uppsala General Catalog (UGC, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/26">CDS Catalog <VII/26></a>) and the European Southern Observatory (ESO) Catalog (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/115">CDS Catalog <VII/115></a>). Well-defined optical criteria were used to select the galaxies, and X-ray fluxes were measured at the optically-defined positions. The result is a comprehensive list of X-ray detection and upper limit measurements for 1018 galaxies. Of these, 827 galaxies have either independent distance estimates or radial velocities. Associated optical, redshift, and distance data have been assembled for these galaxies, and their distances come from a combination of directly predicted distances and those predicted from the Faber-Burstein Great Attractor/Virgocentric infall model. The accuracy of the X-ray fluxes has been checked in three different ways; all are consistent with the derived X-ray fluxes being of <= 0.1 dex accuracy. In particular, there is agreement with previously published X-ray fluxes for galaxies in common with a 1991 study by Roberts et al. (1991ApJS...75..751R) and a 1992 study by Fabbiano et al. (1992ApJS...80..531F, also available at the HEASARC as a database table called EINGALCAT). This database was created at the HEASARC in May 2002 based on the ADC/<a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJS/111/163">CDS Catalog J/ApJS/111/163</a> and is derived from Tables 5, 6, 7, 12, 13, and 14 of the published paper. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/twosigma
- Title:
- Einstein Two-Sigma Catalog
- Short Name:
- Einstein/ETS
- Date:
- 25 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The X-ray sources from observations made with the Einstein Observatory (HEAO-2) Imaging Proportional Counter (IPC) that have intensities of 2-sigma or more above the background are compiled in this catalog. This catalog covers more sky at fainter flux levels than the Einstein Medium Sensitivity Survey. Fields with diffuse emission sources such as bright Abell clusters of galaxies and supernova remnants were excluded. Thus, data within 10 degrees of the galactic plane as well as fields within the boundaries of the Magellanic Clouds were excluded. Regions crowded with galactic sources such as the Orion and Pleiades fiels were also excluded. Excluding redundant fields, this catalog covers 1850 sq. degrees of the sky. The generation of the Einstein Two-Sigma Catalog was described in detail by Moran et al. (1996). Please read this article carefully to ensure responsible use of the Catalog. Detailed scientific and technical questions on the contents and methodology of this catalog should be addressed to the first author, Ed Moran (edhed@igpp.llnl.gov). In particular, it should be noted that, by design, this catalog contains a significant number of spurious sources: only 28%, or about 13,000 sources, out of the 46,000 source in the 2-sigma catalog are `real` astrophysical sources, with the remainder of the sources being spurious ones. Moran et al. show in their paper that performing cross-correlations of 2-sigma sources with other catalogs is an effective way of selecting sources in this catalog that are probably real. This is a service provided by NASA HEASARC .
