Structure of the galaxies of the NGC 80 group: Two-tiered disks
Abstract
Two-color photometric data obtained on the 6-m telescope of the Special Astrophysical Observatory are used to analyze the structure of 13 large disk galaxies in the NGC 80 group. Nine of the 13 studied galaxies are classified as lenticular galaxies. The stellar populations in the galaxies are very diverse, from old stars with ages of T > 10 billion years (IC 1541) to relatively young stars with ages of T ∼ 1-3 billion years (IC 1548, NGC 85); in one case, star formation is ongoing (UCM 0018+2216). In most of the studied galaxies, more precisely in all of them brighter than M B ∼ -18, two-tiered stellar disks are detected, whose radial surface-brightness profiles can be described by two exponential segments with different characteristic scales—shorter near the center and longer at the periphery. All of the dwarf S0 galaxies with single-tiered disks are close companions to larger galaxies. Except for this fact, no dependence of the properties of S0 galaxies on distance from the center of the group is found. Morphological signs of a "minor merger" are found in the lenticular galaxy NGC 85. Based on these last two results, it is concluded that the most probable mechanism for their transformation of spiral into lenticular galaxies in groups is gravitational (minor mergers and tidal interactions).
- Publication:
-
Astronomy Reports
- Pub Date:
- December 2009
- DOI:
- 10.1134/S1063772909120038
- arXiv:
- arXiv:1001.1325
- Bibcode:
- 2009ARep...53.1101S
- Keywords:
-
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 24 pages, 9 figures, slightly improved version of the paper published in the December, 2009, issue of the Astronomy Reports