- ID:
- ivo://nasa.heasarc/hricfa
- Title:
- Einstein Catalog HRI CFA Sources
- Short Name:
- Einstein/HRI
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table consists of a preliminary source list for the Einstein Observatory's High Resolution Imager (HRI). The source list, obtained from EINLINE, the Einstein On-line Service at the Smithsonian Astrophysical Observatory (SAO), contains basic information about the sources detected with the HRI. This is a service provided by NASA HEASARC .
« Previous |
1 - 10 of 13
|
Next »
Number of results to display per page
Search Results
- ID:
- ivo://nasa.heasarc/hrideep
- Title:
- Einstein Catalog HRI Deep Survey
- Short Name:
- EinstHRIDeep
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/hriexo
- Title:
- Einstein Catalog HRI ESTEC Sources
- Short Name:
- HRIEXO
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/ipcdeep
- Title:
- Einstein Catalog IPC Deep Survey
- Short Name:
- IPCDEEP
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- IPCDEEP is created from a table containing basic source parameters for each of the 178 IPC sources detected by the Einstein Deep Survey. The Einstein Deep Survey program (EDS) consists 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 .
- ID:
- ivo://nasa.heasarc/emss
- Title:
- Einstein Catalog IPC EMSS Survey
- Short Name:
- Einstein/EMSS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This database table contains information from the Einstein Extended Medium Sensitivity Survey (EMSS) which consists of 835 serendipitous X-ray sources detected at or above 4 times the rms level in 1435 IPC fields with their centers located away from the galactic plane. Their limiting sensitivities range from ~5*10E-14 to ~3*10-12 ergs cm-3 s-1 in the 0.3-3.5keV band. A total area of 778 square degrees of the high galactic latitude sky (|b|>20) has been covered. The analysis has been performed using data from the Rev 1 processing system at the CfA. The resulting EMSS catalog is a flux-limited and homogeneous sample of astronomical objects that can be used for statistical studies. Additional information is available from the HEASARC. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ipcslew
- Title:
- Einstein Catalog IPC Slew Survey
- Short Name:
- IPCSLEW
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/exss
- Title:
- Einstein Extended Source Survey
- Short Name:
- Einstein/Ext.
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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 .
- ID:
- ivo://nasa.heasarc/ipc
- Title:
- Einstein IPC Sources Catalog
- Short Name:
- Einstein/IPC
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- 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: <pre> 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 </pre> This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/ipcultsoft
- Title:
- Einstein IPC Ultrasoft Sources Catalog
- Short Name:
- IPCUltrasoft
- Date:
- 07 Mar 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 .
- ID:
- ivo://nasa.heasarc/einstein2e
- Title:
- Einstein Observatory 2E Catalog of IPC X-Ray Sources
- Short Name:
- Einstein2E
- Date:
- 07 Mar 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 .
