The Ursa Major Cluster of Galaxies.I.Cluster Definition and Photometric Data (original) (raw)

NASA/ADS

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Abstract

The Ursa Major Cluster has received remarkably little attention, although it is as near as the Virgo Cluster and contains a comparable number of H I-rich galaxies. In this paper, criteria for group membership are discussed and data are presented for 79 galaxies identified with the group. Of these, all 79 have been imaged at B,R,I bands with CCDs, 70 have been imaged at K' with a HgCdTe array detector, and 70 have been detected in the HI 21 cm line. A complete sample of 62 galaxies brighter than M_B_ = - 16.5 is identified. Images and gradients in surface brightness and color are presented at a common linear scale. As has been seen previously, the galaxies with the reddest global colors are reddest at the centers and get bluer at large radii. However, curiously, among the galaxies with the bluest global colors there are systems with very blue cores that get redder at large radii.

Publication:

The Astronomical Journal

Pub Date:

December 1996

DOI:

10.1086/118196

arXiv:

arXiv:astro-ph/9608124

Bibcode:

1996AJ....112.2471T

Keywords:

E-Print:

A LATEX file without figures. The postscript version (7.1Mb in gzipped format) including all the tables, figures and scanned versions of the plates can be retrieved as preprint no.208 from http://www.astro.rug.nl:80/\~secr/ Accepted for publication in The Astronomical Journal