The MCG database contains the "Morphological Catalogue of Galaxies," a compilation of information for approximately 34,000 galaxies found and examined on the Palomar Observatory Sky Survey (POSS). Individual identifiers are assigned for about 29,000 galaxies and information on the remaining 5,000 is present in the extensive notes of the published catalogs (Vorontsov-Velyaminov et al. 1962-1968). The catalog is structured according to the POSS zones and is numbered from +15 (corresponding to +90 deg) to +01 (+06 deg zone) and +00 (equatorial zone) to -05 (-30 deg zone); the fields are numbered with increasing right ascension. The original goal of the compilation was to be complete for galaxies brighter than magnitude 15.1, but the final catalog lists many objects considerably fainter. Information given in the original printed volumes includes: cross- identifications to the NGC (Dreyer 1888) and IC (Dreyer 1895, 1908) catalogs, equatorial coordinates for 1950.0, magnitude, estimated sizes and intensities of the bright inner region and the entire object, estimated inclination, and coded description (by symbols) of the appearance of the galaxy. Each field is then followed by notes on individual objects. All of the above data except the coded description are included in the machine version, except that special coding (e.g. for uncertainty or source designation) is not present (other than for the NGC/IC cross identifications [added at the Astronomical Data Center for this machine version]). Although the notes are not computerized, the presence of a note in the original is flagged in the machine version Detailed descriptions of modifications, corrections and the record format are provided for the machine-readable version of the "Morphological Catalogue of Galaxies" (Vorontsov-Velyaminov et al. 1962-68); see the Additional Information section below. In addition to hundreds of individual corrections, a detailed comparison of the machine-readable with the published catalog resulted in the addition of 116 missing objects, the deletion of 10 duplicate records, and a format modification to increase storage efficiency. This is a service provided by NASA HEASARC .

The CNS3 catalog contains all known stars as of 1991 that are within 25 parsecs of the Sun. It depends mainly on a preliminary version (Spring 1989) of the new General Catalogue of Trigonometric Parallaxes (YPC) prepared by Dr. William F. van Altena (Yale University). The catalog contains every then-known star with a trigonometric parallax greater than or equal to 0.0390 arcsec, even though it may be evident from photometry or for other reasons that the star has a larger distance. For red dwarf stars, new color-magnitude calibrations for broad-band colors were carried out and applied. For white dwarfs, the recipes of McCook and Sion in ApJS, 65, 603 (1987) were applied. Stroemgren photometry was used (not yet systematically) for early-type stars and for late dwarfs, the latter supplied by E. H. Olsen from Copenhagen Observatory (private communication). In contrast to the CNS2 (Gliese 1969) catalog, trigonometric parallaxes and photometric or spectroscopic parallaxes were not combined in this version. The resulting parallax in the present version is the trigonometric parallax if the relative error of the trigonometric parallax is smaller than 14 percent. The parallax may be the photometric or spectroscopic parallax only if no trigonometric parallax is available or if the standard error of the trigonometric parallax is considerably larger. The original catalog and the notes describing it were prepared by Wilhelm Gliese and Hartmut Jahreiss, Astronomisches Rechen-Institut, Moenchhofstrasse 12-14, D-6900 Heidelberg 1, Germany, in 1991. The CDS has made a number of formatting and documentation changes in the period 1994-1997, e.g., in December 1997 it added a running number to the name for 1388 stars which had all been given the same name of "NN" in the original version, starting with "NN 3001" (for the first "NN" star in order of 1950 RA), and ending with "NN 4388" (for the last "NN" star in order of 1950 RA). This revised version of the catalog (CDS/ADC Catalog V/70A) was used by the HEASARC to create this database in February 2001. This is a service provided by NASA HEASARC .

PPMXL is a catalog of positions, proper motions, 2MASS- and optical photometry of 900 million stars and galaxies, aiming to be complete down to about V=20 full-sky. It is the result of a re-reduction of USNO-B1 together with 2MASS to the ICRS as represented by PPMX.

This table contains the machine-readable version of the Third Reference Catalogue of Bright Galaxies (RC3) by G. de Vaucouleurs, A. de Vacouleurs, H.G. Corwin, R.J. Buta, P. Fouque, and G. Paturel, originally published by Springer-Verlag in 1991, and including some corrections and additions made by Corwin et al. (1994, AJ, 108, 2128). Only brief parameter descriptions are given in this help file. Detailed information about, for example, how certain quantities were derived, or exactly what a given code means, can be found in the printed version of RC3. This table was created by the HEASARC in March 2007 based on CDS table VII/155/rc3, and replaced an earlier version which did not contain the corrections made by Corwin et al. This is a service provided by NASA HEASARC .

The PACS Evolutionary Probe (PEP, Lutz et al. 2011) is a Herschel guaranteed time deep extragalactic survey (KPGT_dlutz_1) targeting six among the most popular "blank fields", ten lensing clusters of galaxies, and two z ~1 clusters at wavelengths of 100, and 160 microns. PEP includes SPIRE observations of the two z ~1 clusters at wavelengths of 250, 350, and 500 microns. SPIRE coverage of all other fields is available from the HerMES survey (Oliver et al. 2010). In addition, deep SPIRE GOODS-N data are provided by the GOODS-Herschel program (Elbaz et al. 2011).PEP used the Starfinder IDL code (Diolaiti et al. 2000a,b) to blindly extract the PACS catalogs, by means of PSF-fitting. PEP adopted the "direct" noise maps and extracted PSFs directly from the observed maps (see documentation). The released catalogs include all sources above a S/N threshold of 3 sigma, derived directly from the measured fluxes and flux uncertainties. Users should keep in mind that the error estimate does not take into account confusion noise. PEP recommends to use any flux below 0.6 mJy in the green band and below 2.0 mJy in the red band with care.

This is a catalog of 203 clusters of galaxies serendipitously detected in 647 ROSAT PSPC high Galactic latitude pointings covering 158 square degrees. This is one of the largest X-ray-selected cluster samples, comparable in size only to the ROSAT All-Sky Survey sample of nearby clusters (Ebeling et al. 1997). Clusters in the inner 17.'5 of the ROSAT PSPC field of view are detected using the spatial extent of their X-ray emission. Fluxes of detected clusters range from 1.6 x 10^-14 to 8 x 10^-12 ergs s^-1 cm^-2 in the 0.5-2 keV energy band. X-ray luminosities range from 10⁴² ergs s^-1, corresponding to very poor groups, to ~5 x 10⁴⁴ ergs s^-1, corresponding to rich clusters. The cluster redshifts range from z = 0.015 to z > 0.5. The catalog lists X-ray fluxes, core radii, and spectroscopic redshifts for 73 clusters and photometric redshifts for the remainder. Of 223 X-ray sources, 203 have been optically confirmed as clusters of galaxies. Of the remaining 20 sources, 19 are likely false detections arising from blends of unresolved point X-ray sources. Optical identifications of the remaining object are hampered by a nearby bright star. Above a flux of 2 x 10^-13 ergs s^-1 cm^-2, 98% of extended X-ray sources are optically confirmed clusters. The number of false detections and their flux distribution are in perfect agreement with simulations. The log N-log S relation for clusters derived from this catalog shows excellent agreement with counts of bright clusters derived from the Einstein Extended Medium Sensitivity Survey and the ROSAT All-Sky Survey. At fainter fluxes, its log N-log S relation agrees with the smaller area WARPS survey. The cluster counts appear to be systematically higher than those from a 50 square degree survey by Rosati et al. This database was created by the HEASARC in December 2001 based on the CDS/ADC catalog J/ApJ/502/558/ (table3.dat). This is a service provided by NASA HEASARC .

The PACS Evolutionary Probe (PEP, Lutz et al. 2011) is a Herschel guaranteed time deep extragalactic survey (KPGT_dlutz_1) targeting six among the most popular "blank fields", ten lensing clusters of galaxies, and two z ~1 clusters at wavelengths of 100, and 160 microns. PEP includes SPIRE observations of the two z ~1 clusters at wavelengths of 250, 350, and 500 microns. SPIRE coverage of all other fields is available from the HerMES survey (Oliver et al. 2010). In addition, deep SPIRE GOODS-N data are provided by the GOODS-Herschel program (Elbaz et al. 2011).PEP used the Starfinder IDL code (Diolaiti et al. 2000a,b) to blindly extract the PACS catalogs, by means of PSF-fitting. PEP adopted the "direct" noise maps and extracted PSFs directly from the observed maps (see documentation). The released catalogs include all sources above a S/N threshold of 3 sigma, derived directly from the measured fluxes and flux uncertainties. Users should keep in mind that the error estimate does not take into account confusion noise. PEP recommends to use any flux below 0.6 mJy in the green band and below 2.0 mJy in the red band with care.