- ID:
- ivo://CDS.VizieR/J/ApJS/111/163
- Title:
- Einstein X-ray survey of galaxies. I.
- Short Name:
- J/ApJS/111/163
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a complete Einstein imaging proportional counter X-ray survey of optically-selected galaxies from the Shapley-Ames Catalog (Cat. <VII/112>), the Uppsala General Catalog (Cat. <VII/26>) and the European Southern Observatory Catalog (Cat. <VII/115>). Well-defined optical criteria are used to select the galaxies, and X-ray fluxes are 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 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).The data presented here will be used in further studies to characterize the X-ray output of galaxies of various morphological types and thus to enable the determination of the major sources contributing to the X-ray emission from galaxies.
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12. EMSS
- ID:
- ivo://CDS.VizieR/J/ApJS/99/701
- Title:
- EMSS
- Short Name:
- J/ApJS/99/701
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present X-ray data from the ROSAT all-sky survey for those sources catalogued in the Einstein Extended Medium Sensitivity Survey (EMSS) (Cat. <VII/152>) which have been identified with Galactic stars. This "second epoch" of X-ray data taken 10yr later, is used to study coronal flux variability for the most active examples of late-type stars. About 72% of the EMSS stars have been redetected by ROSAT. While the F-stars appear to have remained constant, we find evidence for a general decrease in X-ray flux for the M and solar-type stars. This is probably due to the fact that an X-ray-selected sample will preferentially detect stars while flaring. In contradiction to this, the RS CVn binaries have been redetected at higher X-ray flux levels for the sample as a whole.
- ID:
- ivo://CDS.VizieR/J/ApJ/348/253
- Title:
- Late type giants and supergiants in X-Ray
- Short Name:
- J/ApJ/348/253
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results are presented of an extensive X-ray survey of 380 giant and supergiant stars of spectral types from F to M, carried out with the Einstein Observatory. It was found that the observed F giants or subgiants (slightly evolved stars with a mass M less than about 2 solar masses) are X-ray emitters at the same level of main-sequence stars of similar spectral type. The G giants show a range of emission more than 3 orders of magnitude wide; some single G giants exist with X-ray luminosities comparable to RS CVn systems, while some nearby large G giants have upper limits on the X-ray emission below typical solar values. The K giants have an observed X-ray emission level significantly lower than F and F giants. None of the 29 M giants were detected, except for one spectroscopic binary.
14. The 2E Catalogue
- ID:
- ivo://CDS.VizieR/IX/13
- Title:
- The 2E Catalogue
- Short Name:
- IX/13
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalog contains sources from EINSTEIN IPC (Imaging Proportional counter aboard the EINSTEIN (HEAO 2) satellite, in orbit between November 1978 and April 1981) detected during pointed observations. Note that a single source may have more than one entry in the catalog.
- ID:
- ivo://CDS.VizieR/IX/24
- Title:
- The Einstein Observatory HRI Source List
- Short Name:
- IX/24
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Einstein Observatory is the second of NASA's three High Energy Astrophysical Observatories, HEAO-2, renamed Einstein after launch, and was the first fully imaging X-ray telescope put into space. It observed in the energy range 0.2-20keV. It was launched on 12 November 1978, and remained in operation until April 1981. The High Resolution Imager (HRI) is one fo the four instruments aboard the Einstein Observatory, operating in the 0.2-3.0keV energy range, with a spatial resolution of a few arcseconds, and a field of view of 25arcmin. Field and source parameters observed with this instrument are given here.
- ID:
- ivo://CDS.VizieR/J/ApJ/461/127
- Title:
- The Einstein Two-Sigma Catalog
- Short Name:
- J/ApJ/461/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The X-ray sources from the observations with the Einstein Observatory (HEAO-2) with intensities of 2-sigma 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 were excluded. Thus data within 10 degrees of the galactic plane as well as fields within the boundaries of the Magellanic Clouds were excluded. The 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). Read this article carefully to ensure responsible use of the Catalog. Address any questions to Ed Moran (edhed@igpp.llnl.gov). In particular it should be noted that only 28%, or about 13,000 sources in the 2-sigma catalog are real sources. The authors show that cross-correlations with other catalogs is an effective way to select sources in this catalog that are probably real.
- ID:
- ivo://CDS.VizieR/J/ApJ/414/846
- Title:
- X-ray emission at the low-mass end
- Short Name:
- J/ApJ/414/846
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used all tha available data from the Einstein Observatory Imaging Proportional Counter (IPC), and a critical compilation of catalogued optical data, to measure the 0.16-3.5 keV X-ray emission from 88 K and 169 M stars of luminosity classes IV, V and VI within 25 pc from the Sun. The IPC detected 54 out of the 88 K stars, 70 out of the 138 M stars with M_v_ less than 13.4 (corresponding approximatively to M5), and 15 out of the 31 fainter M stars. We have identified a subsample of surveyed stars that is statistically representative of the population of K and M stars in the solar neighborhood.
- ID:
- ivo://CDS.VizieR/J/ApJ/315/687
- Title:
- X-Ray emission from solar-type stars: F and G
- Short Name:
- J/ApJ/315/687
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results of a volume-limited X-ray survey of stars of luminosity classes IV and V in the spectral range F7-G9 observed with the Einstein Observatory are presented. Using survival analysis techniques, the stellar X-ray luminosity function in the 0.15-4.0 keV energy band for both single and multiple sources. It is shown that the difference in X-ray luminosity between these two classes of sources is consistent with the superposition of individual components in multiple-component systems, whose X-ray properties are similar to those of the single-component sources. The X-ray emission of the stars in our sample is well correlated with their chromospheric CA II H-K line emission and with their projected equatorial rotational velocity. Comparison of the X-ray luminosity function constructed for the sample of the dG stars of the local population with the corresponding functions derived elsewhere for the Hyades, the Pleiades, and the Orion Ic open cluster confirms that the level of X-ray emission decreases with stellar age.
- ID:
- ivo://CDS.VizieR/J/ApJ/351/492
- Title:
- X-ray emission in the Ursa Major stream.
- Short Name:
- J/ApJ/351/492
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results are reported from a comprehensive survey of X-ray emission from stars known or suspected to be members of the UMa cluster and/or stream. Of the 42 UMa member stars surveyed, 18 were detected as X-ray sources, and spectral analysis was performed for 10 stars with sufficient X-ray counts. Consideration is given to relations between X-ray luminosity, color, and kinematics of the sample stars, and the X-ray spectra of the UMa stars are discussed in the context of the general problem of stellar X-ray temperatures. Also confirmed is the lack of X-ray-emitting A dwarfs among UMa members; among stars of later spectral type there is a rather large dispersion in X-ray luminosity. This dispersion cannot readily be explained by contamination with field star interlopers and appears rather to be a property of the UMa X-ray luminosity distribution function.
- ID:
- ivo://CDS.VizieR/J/ApJS/73/781
- Title:
- X-ray observations of galactic Supernova Remnants
- Short Name:
- J/ApJS/73/781
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper summarizes the observations of Galactic supernova remnants with the imaging detectors of the Einstein Observatory. X-ray surface brightness contours of 47 remnants are shown together with gray-scale pictures. Count rates for these remnants have been derived and are listed for the HRI, IPC, and MPC detectors.
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