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The 2MASS-selected Flat Galaxy Catalog
An all-sky catalog of 18020 disc-like galaxies is presented. Thegalaxies are selected from the Extended Source Catalog of the Two MicronAll-Sky Survey (XSC 2MASS) basing on their 2MASS axial ratio a/b ≥ 3.The Catalog contains data on magnitudes of a galaxy in the J, H,KS bands, its axial ratio, positional angle, index ofluminosity concentration, as well as identification of the galaxy withthe LEDA and the NED databases. Unlike the available optical catalogs,the new 2MFGC catalog seems to be more suitable to study cosmicstreaming on a scale of z <~ 0.1. The dipole moment of distributionof the bright (K < 11m) 2MFGC objects (l = 227°, b =41° or SGL = 90°, SGB = -43°) lies within statistical errors(±15°) in the direction of the IRAS dipole and the opticalRFGC dipole.
| Nearby Optical Galaxies: Selection of the Sample and Identification of Groups
In this paper we describe the Nearby Optical Galaxy (NOG) sample, whichis a complete, distance-limited (cz<=6000 km s-1) andmagnitude-limited (B<=14) sample of ~7000 optical galaxies. Thesample covers 2/3 (8.27 sr) of the sky (|b|>20deg) andappears to have a good completeness in redshift (97%). We select thesample on the basis of homogenized corrected total blue magnitudes inorder to minimize systematic effects in galaxy sampling. We identify thegroups in this sample by means of both the hierarchical and thepercolation ``friends-of-friends'' methods. The resulting catalogs ofloose groups appear to be similar and are among the largest catalogs ofgroups currently available. Most of the NOG galaxies (~60%) are found tobe members of galaxy pairs (~580 pairs for a total of ~15% of objects)or groups with at least three members (~500 groups for a total of ~45%of objects). About 40% of galaxies are left ungrouped (field galaxies).We illustrate the main features of the NOG galaxy distribution. Comparedto previous optical and IRAS galaxy samples, the NOG provides a densersampling of the galaxy distribution in the nearby universe. Given itslarge sky coverage, the identification of groups, and its high-densitysampling, the NOG is suited to the analysis of the galaxy density fieldof the nearby universe, especially on small scales.
| Galaxy coordinates. II. Accurate equatorial coordinates for 17298 galaxies
Using images of the Digitized Sky Survey we measured coodinates for17298 galaxies having poorly defined coordinates. As a control, wemeasured with the same method 1522 galaxies having accurate coordinates.The comparison with our own measurements shows that the accuracy of themethod is about 6 arcsec on each axis (RA and DEC).
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