The ROSAT All-Sky Survey Catalogue of Optically Bright Late-Type Giant and Supergiant Stars contains X-ray data for all late-type (spectral types of A through M, inclusive) giants and supergiants (luminosity classes of I through III-IV, inclusive) listed in the Bright Star Catalogue (BSC) that have been detected in the ROSAT All-Sky Survey. The RASS giants and supergiants catalog contains 450 entries of X-ray emitting, evolved late-type stars, which corresponds to an average detection rate of 11.7 percent. For each star, the ROSAT PSPC count rate, the hardness ratio, the apparent X-ray flux (calculated using an individual energy-conversion-factor based on the hardness ratio), and the ratio of X-ray to bolometric flux are given. The full details of the data selection, the source detection criteria, etc., are given in the paper by Huensch, Schmitt and Voges (1998, A&AS, 127, 251) describing this catalog; essentially for a star to be identified as an X-ray source, the X-ray source had to have at least a 99.9 percent existence probability, corresponding to a likelihood of greater than or equal to 7, and lie within 90 arcseconds of the optical position. Given the number of sky locations examined and the total number of RASS sources, it is expected that of order 27.4 of the 450 claimed associations in this catalog will be chance coincidences. This database was created at the HEASARC in July 1998 based on the ADC/CDS Catalog J/A+AS/127/251. This is a service provided by NASA HEASARC .

The authors of this catalog carried out a study of the X-ray properties of the supernova remnant (SNR) population in M 33 with XMM-Newton, comprising deep observations of eight fields in M 33 covering all of the area within the D₂₅ contours, and with a typical luminosity of 7.1 x 10³⁴ erg/s (0.2-2.0keV). With their deep observations and large field of view they have detected 105 SNRs at the 3-sigma level, of which 54 SNRs are newly detected in X-rays, and three are newly discovered SNRs. Combining XMM-Newton data with deep Chandra survey data allowed detailed spectral fitting of 15 SNRs, for which they have measured temperatures, ionization time-scales and individual abundances. This large sample of SNRs allowed the authors to construct an X-ray luminosity function, and compare its shape to luminosity functions from host galaxies of differing metallicities and star formation rates to look for environmental effects on SNR properties. They concluded that while metallicity may play a role in SNR population characteristics, differing star formation histories on short time-scales, and small-scale environmental effects appear to cause more significant differences between X-ray luminosity distributions. In addition, they analyze the X-ray detectability of SNRs, and find that in M 33 SNRs with higher [SII]/H-alpha ratios, as well as those with smaller galactocentric distances, are more detectable in X-rays. This catalog utilized data from a deep survey of M 33 using an 8 field XMM-Newton mosaic that extends out to the D25 isophote. The point source catalog from this survey was published by W15 (Williams+2015, J/ApJS/218/9). In addition to the catalog of W15, the authors utilized high-resolution observations from the Chandra ACIS Survey of M 33 (ChASeM33, Tullmann+2011, J/ApJS/193/31) for the purposes of obtaining X-ray spectral fits. This table was ingested by the HEASARC in October 2019 based upon the CDS Catalog J/MNRAS/472/308 files table2.dat and table3.dat. This is a service provided by NASA HEASARC .

This is a catalog of galaxies observed in the X-ray band with the Einstein Observatory imaging instruments, the Imaging Proportional Counter (IPC) and the High Resolution Imager (HRI). The catalog comprises 716 observations of 493 galaxies, including those that were targets of pointed observations, and galaxies from the Revised Shapley-Ames (RSA) Catalog of Bright Galaxies and the Second Revised Catalog (RC2) Catalog of Bright Galaxies that were serendipitously included in Einstein fields, plus X-ray data on 4 other galaxies (LMC, SMC, M 31 = NGC 224, and M 32 = NGC 221) taken from the literature, for a total of 720 entries. A total of 450 of these galaxies were imaged well within the instrumental fields, resulting in 238 detections and 212 3-sigma upper limits. The other galaxies were either at the edge of the visible field of view or were confused with other X-ray sources. This database was created by the HEASARC in January 2002 based on CDS Catalog J/ApJS/80/531, tables gxatlas.dat and gxfluxes.dat. This is a service provided by NASA HEASARC .

This table contains the dynamic version of the Asiago Supernova Catalog. It supersedes the original 1999 version by Barbon et al. (1999A&AS..139..531B, Cat. II/227), and contains data about the supernovae observed since 1885 and their parent galaxies through a few days prior to the most recent update. In addition to the list of newly discovered SNe, the literature has been searched for new information on past SNe as well. The data for the parent galaxies have also been homogenized. This table was created by the HEASARC based on the CDS Catalog B/sn. The CDS updates it regularly, and this HEASARC version is accordingly updated within a week of such updates. This is a service provided by NASA HEASARC .

The combination of the Sloan Digital Sky Survey (SDSS) and the Chandra Multiwavelength Project (ChaMP; Green et al. 2004, ApJS, 150, 43) currently offers the largest and most homogeneously selected sample of nearby galaxies for investigating the relations between X-ray nuclear emission, nebular line emission, black hole masses, and the properties of the associated stellar populations. The authors provide X-ray spectral fits and valid uncertainties for all the galaxies with counts ranging from 2 to 1325 (mean 76, median 19). They present in their paper novel constraints that both X-ray luminosity L_X and X-ray spectral energy distribution bring to the galaxy evolutionary sequence HII -> Seyfert/Transition Object -> LINER -> Passive suggested by optical data. In particular, the authors show that both L_X and Gamma, the slope of the power law that best fits the 0.5 - 8 keV spectra, are consistent with a clear decline in the accretion power along the sequence, corresponding to a softening of their spectra. This implies that, at z ~ 0, or at low-luminosity active galactic nucleus (AGN) levels, there is an anticorrelation between Gamma and L/L_Edd, opposite to the trend which is exhibited by high-z AGN (quasars). The turning point in the Gamma - L/L_Edd LLAGN + quasars relation occurs near Gamma ~ 1.5 and L/L_Edd ~ 0.01. Interestingly, this is identical to what stellar mass X-ray binaries exhibit, indicating that the authors have probably found the first empirical evidence for an intrinsic switch in the accretion mode, from advection-dominated flows to standard (disk/corona) accretion modes in supermassive black hole accretors, similar to what has been seen and proposed to happen in stellar mass black hole systems. The anticorrelation the authors find between Gamma and L/L_Edd may instead indicate that stronger accretion correlates with greater absorption. Therefore, the trend for softer spectra toward more luminous, high-redshift, and strongly accreting (L/L_Edd >~ 0.01) AGNs/quasars could simply be the result of strong selection biases reflected in the dearth of type 2 quasar detections. The cross-match of all ChaMP sky regions imaged by Chandra/ACIS with the SDSS DR4 spectroscopic footprint results in a parent sample of 15,955 galaxies on or near a chip and a subset of 199 sources that are X-ray detected. Among those, only 107 sources have an off-axis angle (OAA) Theta <0.2 degrees and avoid ccd=8 due to high serial readout noise; these 107 objects comprise the main sample that the authors employ for this study and that are listed in this table. The authors performed direct spectral fits to the X-ray counts distribution using the full instrument calibration, known redshift, and Galactic 21-cm column nH_Gal. Source spectra were extracted from circular regions with radii corresponding to energy encircled fractions of ~90%, while the background region encompasses a 20 arcsec annulus, centered on the source, with separation 4 arcsecs, from the source region. Any nearby sources were excised, from both the source and the background regions. The spectral fitting was done via yaxx ('Yet Another X-ray eXtractor': Aldcroft 2006, BAAS, 38, 376), an automated script that employs the CIAO Sherpa tool. Each spectrum was fitted in the range 0.5 - 8 keV by two different models: (1) a single power law plus absorption fixed at the Galactic 21-cm value (model 'PL'), and (2) a fixed power law of photon index Gamma = 1.9 plus intrinsic absorption of column nH (model 'PLfix'). For the nine objects with more than 200 counts, the authors employed a third model in which both the slope of the power law and the intrinsic absorption were free to vary (model 'PL_abs'). This table was created by the HEASARC in January 2012 based on CDS Catalog J/ApJ/705/1336/ file table1.dat. This is a service provided by NASA

This catalog of known Galactic supernova remnants (SNRs) is an updated version of the catalogs of Galactic SNRs presented in detail in Green (1984, 1988), in summary form in Green (1991, 1996, 2004, 2009), and on the Web (versions of 1995-July, 1996-August, 1998-September, 2000-August, 2001-December, 2004-January, 2006-April, 2009-March, and 2014-May). [Note that the version published in Green (1996) was produced in 1993.] This June 2017 version of the catalog contains 295 SNRs, and is based on results published in the literature up to the end of 2016. The basic summary data included in this catalog for each SNR are its designation, position, angular size (in arcminutes), type, flux density at 1 GHz, spectral index, and any other names by which it is known. Notes on these parameters, on possible remnants not included, and on questionable SNRs that are listed in this catalog, are given in the full version of the catalog on the Web at http://www.mrao.cam.ac.uk/surveys/snrs/snrs.info.html It should be noted that there are serious selection effects which apply to the identification of Galactic SNRs (e.g., Green 1991, 2004, 2005, 2009, 2014), so that care should be taken if these data are used in any statistical studies. This version of the Green Catalog of Galactic Supernova Remnants was ingested at the HEASARC in July 2017. It is based on the Catalogue of Galactic Supernova Remnants, 2017 June version, CDS Catalog VII/278, file snrs.dat, obtained from the CDS at http://cdsarc.u-strasbg.fr/ftp/cats/VII/278/. This is a service provided by NASA HEASARC .

In a correlation study of the ROSAT All-Sky Survey Bright Source Catalog (RASS-BSC, CDS Cat. , the HEASARC table RASSBSC) with the Catalogue of Principal Galaxies (PGC, CDS Cat. , the HEASARC table PGC2003), 904 X-ray sources were found that possess possible extragalactic counterparts within a search radius of 100 arcseconds. A visual screening process was applied to classify the reliability of the correlations. 547 correlations have been quoted as reliable identifications. From these, 349 sources are known to be active galaxies. Although for the other sources no hints for activity were found in the literature, 69% of those for which we have distances show X-ray luminosities exceeding those of normal galaxies, a clear sign that these galaxies also own hitherto unreported X-ray active components. Some objects are located inside or in the direction of a known group or cluster of galaxies. Their X-ray flux may therefore be in part affected by hot gas emission. In the paper, luminosity and log N-log S distributions are used to characterize different subsamples. Nuclei that are both optically and X-ray active are found predominantly in spirals. Two special source samples are defined, one with candidates for X-ray emission from hitherto unknown groups or clusters of galaxies, and one with high X-ray luminosity sources, that are likely candidates to possess hitherto unreported active galactic nuclei. Besides a compilation of X-ray and optical parameters, X-ray overlays on optical images for all the objects are also supplied as part of this work. This table contains 1124 optical galaxy entries for the 904 relevant X-ray candidates/counterparts from the RASS. Besides a compilation of X-ray and optical parameters for each source, the results of an identification screening are also given. The 904 optical images with X-ray overlay contours (xID_nnn.ps.gz) used in the screening process are added for each user's own judgement of the reliability of the associations. This table was created by the HEASARC in March 2012 based on CDS catalog J/A+A/378/30 file table1.dat, the list of PGC galaxies identified as possible counterparts to RASS Bright Source Catalog X-ray sources. This is a service provided by NASA HEASARC .