2008/08/25 by E. Manthey, S. Huettemeister, Susanne Hüttemeister +3 · 8 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy merger #Interacting galaxy #Physics #Radio telescope #Star formation #Stars #Telescope #astro-ph
paper · pdf · doi:10.1051/0004-6361:200810408
published in Astronomy and Astrophysics 490(3), 975-987 (EDP Sciences) · accepted by A&A, 16 pages, movies of the simulations can be found at http://www.bjerkeli.se/
openalex publication_date 2008/08/25 · arxiv created 2008/08/28 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Medusa (NGC 4194) is a well-studied nearby galaxy with the disturbed appearance of a merger and evidence for ongoing star formation. In order to test whether it could be the result of an interaction between a gas-rich disk-like galaxy and a larger elliptical, we have carried out optical and radio observations of the stars and the gas in the Medusa, and performed N-body numerical simulations of the evolution of such a system. We used the Nordic Optical Telescope to obtain a deep V-band image and the Westerbork Radio Synthesis Telescope to map the large-scale distribution and kinematics of atomic hydrogen. A single Hi tail was found to the South of the Medusa with a projected length of ~56 kpc (~) and a gas mass of 7 , thus harbouring about one third of the total Hi mass of the system. Hi was also detected in absorption toward the continuum in the center. Hi was detected in a small nearby galaxy to the North-West of the Medusa at a projected distance of 91 kpc. It is, however, unlikely that this galaxy has had a significant influence on the evolution of the Medusa. The simulations of the slightly prograde infall of a gas-rich disk galaxy on an larger, four time more massive elliptical (spherical) galaxy reproduce most of the observed features of the Medusa. Thus, the Medusa is an ideal object to study the merger-induced star formation contribution from the small galaxy of a minor merger.