Detailed Photometric Study of the Merging Group of Galaxies HCG 95

Iglesias-Páramo, J.; Vílchez, J. M.
Bibliographical reference

The Astronomical Journal, Volume 115, Issue 5, pp. 1791-1800.

Advertised on:
5
1998
Number of authors
2
IAC number of authors
2
Citations
11
Refereed citations
10
Description
Results from Hα + continuum and Johnson UBVI imaging for HCG 95 are presented in order to study the star formation history of the galaxies in the group. Based on the spatial distribution of the stellar populations, as well as the morphology of the three-galaxy system A-C1-C2, we propose two possible scenarios for the dynamical evolution of this system: In one of them, each of the nuclei C1 and C2 interacted with the elliptical galaxy at different times, and we are seeing both nuclei together as a projection effect. The other scenario suggests that both nuclei are involved in a merging process, with the resulting merger remnant interacting with the elliptical galaxy. The recent star formation of the system is strongly balanced toward the northern tidal tail and the nucleus C1. We note the presence of a candidate of a young dwarf galaxy which would have been created at the tip of one of the northern tidal tails. A very young population and no signs of an underlying population were detected for this object. Recent spectroscopic observations of the galaxy HCG 95 B yielded a value for its radial velocity of 8000 km s^-1, that is, more than 3000 km s^-1 less than the rest of galaxies in the group. This new result would imply that galaxy B is a foreground galaxy instead of being physically associated with the group HCG 95. This galaxy appears distorted probably as a result of the close passage of a dwarf satellite that has been detected in the broadband frames and in Hα.