EINGALCLUS - Einstein Observatory Clusters of Galaxies Catalog
Einstein Observatory Images of Clusters of Galaxies Jones C., and Forman W. <Astrophys. J. 511, 65 (1999)> =1999ApJ...511...65J
The name of the cluster of galaxies, where the designation of 'A' stands for an "Abell" cluster, the recommended prefix for which is 'ACO'. In a number of cases where clusters have multiple, spatially resolved subclusters, there are multiple entries for individual clusters, and suffixes such as 'N', 'S', or 'SS' or used to differentate the subclusters.
This flag is set to 'L' to indicate less accurate values (RA values given to 0.1 minutes of time and Dec values to 1 arcminute), for the positional coordinates (typically given to 0.1 seconds of time and 1 arcsecond).
The Right Ascension of the cluster of galaxies, in the selected equinox. The position given is generally the peak of the X-ray surface brightness, except for a few clusters in which the peak is offset from the cluster centroid, as in, for example, SC 0559-40 or A754, or in which, even in the central region, the cluster has multiple surface brightness peaks, as in the case of Coma. For these clusters, the position is that of the X-ray centroid. The RA was given in 1950 coordinates in the originating table, and to a precision of 0.1 seconds of time, except for cases for which position_flag has a value of 'L' which were given only to a precision of 0.1 minutes of time.
The Declination of the cluster of galaxies, in the selected equinox. The position given is generally the peak of the X-ray surface brightness, except for a few clusters in which the peak is offset from the cluster centroid, as in, for example, SC 0559-40 or A754, or in which, even in the central region, the cluster has multiple surface brightness peaks, as in the case of Coma. For these clusters, the position is that of the X-ray centroid. The Dec was given in 1950 coordinates in the originating table, and to a precision of 1 arcsecond, except for cases for which position_flag has a value of 'L' which were given only to a precision of 1 arcminute.
The Galactic Longitude of the cluster of galaxies.
The Galactic Latitude of the cluster of galaxies.
The redshift of the cluster of galaxies.
The reference code for the cluster redshift as follows:
ACO 1989ApJS...70....1A Abell+ 1989 B 1995A&AS..109..147B Brinkmann et al. 1995 (added at CDS, missing in the paper) BB 1985AJ.....90.1413B Batuski & Burns 1985 BD 1994A&A...283..407B Braine & Dupraz 1994 BG 1982AJ.....87.1245B Burns & Gregory 1982 BJ 1994ApJ...424...59B Breen+ 1994 BP 1994ApJ...423...94B Burns+ 1994 C 1995MNRAS.274.1071C Collins+ 1995 D 1980ApJS...42..565D Dressler 1980 deV ................... de Vaucouleurs, G., de Vaucouleurs, A., Corwin, H., Buta, R., Paturel, G., & Fouque, P. 1991, Third Reference Catalogue of Bright Galaxies (New York: Springer) DGF 1994AJ....107..427D Dell'Antonio, Geller, & Fabricant 1994 DS 1994MNRAS.269..151D Dalton+ 1994 GMT 1993A&AS..100...33G Garilli, Maccagni, & Tarenghi 1993 H 1990ApJ...365...66H Huchra+ 1990 HMS 1956AJ.....61...97H Humason, Mayall, & Sandage 1956 JFN 1987MNRAS.224...75J Johnstone, Fabian, & Nulsen 1987 KL 1994A&A...228..122K Kim+ 1994 LO 1995AJ....109..853L Ledlow & Owen 1995 LvdB 1977ApJS...34..381L Leir & van den Berg 1977 MMM 1963ApJ...137..153M Maltby, Mathews, & Moffet 1963 M10 ................... redshift based on magnitude of the tenth-brightest galaxy M10P 1992ApJ...384..404P Postman, Huchra, & Geller 1992 N 1981ApJS...45..613N Noonan 1982 OSC 1988A&AS...73..125O Olowin, de Souza & Chincarini P 1992ApJ...384..404P Postman, Huchra, & Geller 1992 PL 1995ApJ...440...28P Postman & Lauer 1995 QR 1995ApJS...96..343Q Quintana & Ramirez 1995 RK 1988A&AS...72..243R Rhee & Katgert 1988 S 1982A&A...108...L7S Sarazin, Rood, & Struble 1982 Sp 1985PASP...97..932S Spinrad+ 1985 SR 1987ApJS...63..543S Struble & Rood 1987 SR 2 1991ApJS...77..363S Struble & Rood 1991 SW 1991ApJS...76..813S Stocke+ 1991 TCG 1990ApJS...72..715T Teague, Carter, & Gray 1990 Z 1993AJ....106.1273Z Zabludoff+ 1993
The IPC count rate, in counts/s, in the 0.5-4.5keV energy band (IPC PI channels 4-11) within a fixed linear aperture selected, if possible, to be a 1 Mpc radius (with an assumed Hubble Constant of 50 km/s/Mpc). This count rate value has been background subtracted and vignetting corrected. If the source count rate exceeded at least 3 times the count rate uncertainty in the region, this is considered to be a positive detection.
The uncertainty in the IPC count rate, in counts/s.
The radius of the region inside which the IPC count rate was measured, in Mpc. This was chosen, if possible, to be 1 Mpc (with an assumed Hubble Constant of 50 km/s/Mpc). It was not always possible to determine the count rate within 1 Mpc of the cluster center, however. For clusters with redshifts less than 0.035, the 1 Mpc radius region is partially obscured by the IPC window support structure. For redshifts less than 0.02, part of the 1 Mpc region lies outside the IPC field of view (FOV). For those clusters which were not centered in the detector FOV, the rib obscuration occurred at a variety of radii depending on the cluster redshift and its location on the detector. For all such cases, the authors used the largest possible radial region to determine the count rate and extrapolated the measured count rate to that expected within a 1 Mpc radius.
An upper limit flag for the cluster X-Ray luminosity.
The X-Ray (0.5 - 4.5 keV) cluster luminosity, in ergs/s, given for the 1 Mpc radius and extrapolated, if necessary, from that measured, based on the surface brightness parameters. If the source was not detected at a 3-sigma level, lx_limit is set to '<' and the quoted value is a 3-sigma upper limit to the X-ray luminosity. The luminosity reported has had an X-ray K-correction applied, so that the value is in the 0.5 - 4.5 keV band at the source.
The uncertainty in the cluster X-Ray luminosity, in erg/s (not given if the quoted X-ray luminosity is an upper limit).
The measured cluster gas temperature, in keV.
The Galactic Hydrogen column density, in H atoms per cm^2.
The cluster bolometric luminosity, in ergs/s, calculated using either the measured (given by the tx parameter) or estimated (see Section 3.1 of the published paper) gas temperature, within 1 Mpc radius.
The derived or assumed cluster core radius, in Mpc. This is one of the parameters used to characterize the radial surface brightness distribution of the cluster: see equation (1) of the published paper.
The uncertainty in the cluster core radius, in Mpc.
The derived or assumed beta parameter. This is one of the parameters used to characterize the cluster radial surface brightness distribution: see equation (1) of the published paper).
The uncertainty in the beta parameter.
The method used to fit the cluster surface brightness distribution. As discussed in Section 2.3 of the published paper, four different methods were used, which are flagged as follows:
m = Central cluster region excluded from fit d = beta fixed at 0.6 r = cluster size determined by ratio of cluster counts calculated at different cluster radii D = clusters with unconstrained structural parameters
The radiative cooling time of the gas at the cluster center, in units of 10^10 years (10 Gyr).
The gas density at the cluster center, in units of 10^-3 cm^-3, determined using the cluster X-ray luminosity and the measured gas-density profile parameters (core radii and beta values), as discussed in Section 3.3 of the published paper. This was done for detected clusters with a single component or at least a dominant subcluster.
The gas mass within 1 Mpc, in units of 10^14 solar masses, determined using the cluster X-ray luminosity and the measured gas-density profile parameters (core radii and beta values), as discussed in Section 3.3 of the published paper. This was done for detected clusters with a single component or at least a dominant subcluster.
The gas mass within 5 core radii, in units of 10^14 solar masses.
The total virial mass of the cluster within 1 Mpc radius, in units of 10^14 solar masses (see Section 3.4 of the published paper).
The total virial mass of the cluster within 5 core radii, in units of 10^14 solar masses.
The Bautz-Morgan classification of the cluster.
The richness class of the cluster.
The number of galaxies in the cluster.
A flag indicating the X-Ray morphological classification of the cluster, as follows:
s = single symmetric peak o = offset center e = elliptical c = complex, multiple structures d = double, roughly equal components p = primary with small secondary g = primarily galaxy emission