The system ESO 296-IG11

Citation
El. Aguero et al., The system ESO 296-IG11, ASTRONOM J, 117(3), 1999, pp. 1151-1157
Citations number
22
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMICAL JOURNAL
ISSN journal
00046256 → ACNP
Volume
117
Issue
3
Year of publication
1999
Pages
1151 - 1157
Database
ISI
SICI code
0004-6256(199903)117:3<1151:TSE2>2.0.ZU;2-7
Abstract
We present photometric and spectroscopic observations of the system ESO 296 -IG11, which is composed of two galaxies, as well as observations of a smal l galaxy 1.'3 distant. Colors through the entire system show little variati on and reflect the presence of about the same young stellar composition. Th e quite blue colors of the observed regions in both galaxies of the system indicate star formation activity, and the distribution of the regions throu gh the bodies of the galaxies suggests that a quite generalized starburst h as taken place. The spectra of these regions are characteristic of H II reg ions of comparatively high excitation; their oxygen and nitrogen abundances are low, and their N(N)/N(O) ratios are comparable to those of the Magella nic Clouds and late spiral galaxies. The low abundances of the regions woul d be consistent with the ages derived for the bursts of star formation in t heir interiors. The high equivalent widths of the H alpha + [N II] emission lines of the integrated spectra of both galaxies indicate enhanced star fo rmation rates compared with isolated galaxies and are compatible with those observed in mergers of two disk galaxies. The velocities indicate that the two galaxies are a physical pair and that they are linked with the small n earby galaxy. The derived information suggests that ESO 296-IG11 is compose d of two advanced late-type galaxies with similar general properties, which , together with the small nearby galaxy, constitute a triple system.