Star-formation properties of Hickson Compact Groups based on deep Hα imaging

Author(s)
Paul Eigenthaler, Sylvia Plöckinger, Miguel Anibal Verdugo Olivares, Bodo Ziegler
Abstract

We present deep Hα imaging of seven Hickson Compact Groups (HCGs) using the 4.1-m Southern Astrophysics Research (SOAR) Telescope. The high spatial resolution of the observations allows us to study both the integrated star formation properties of the main galaxies as well as the 2D distribution of star-forming knots in the faint tidal arms that form during interactions between the individual galaxies. We derive star formation rates and stellar masses for group members and discuss their position relative to the main sequence of star-forming galaxies. Despite the existence of tidal features within the galaxy groups, we do not find any indication for enhanced star formation in the selected sample of HCGs. We study azimuthally averaged Hα profiles of the galaxy discs and compare them with the g′ and r′ surface brightness profiles. We do not find any truncated galaxy discs but reveal that more massive galaxies show a higher light concentration in Hα than less massive ones. We also see that galaxies that show a high light concentration in r′, show a systematic higher light concentration in Hα. Tidal dwarf galaxy (TDG) candidates have been previously detected in R-band images for two groups in our sample but we find that most of them are likely background objects as they do not show any emission in Hα. We present a new TDG candidate at the tip of the tidal tail in HCG 91.

Organisation(s)
Department of Astrophysics
External organisation(s)
Pontificia Universidad Católica de Chile, Leiden University
Journal
Monthly Notices of the Royal Astronomical Society
Volume
451
Pages
2793 - 2813
No. of pages
21
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/stv1037
Publication date
08-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy, 103004 Astrophysics
Keywords
ASJC Scopus subject areas
Astronomy and Astrophysics, Space and Planetary Science
Portal url
https://ucrisportal.univie.ac.at/en/publications/starformation-properties-of-hickson-compact-groups-based-on-deep-h-imaging(6ad6a578-113e-4ef5-a603-2349e6e3b112).html