Starburst in the Intragroup Medium of Stephan's Quintet
Abstract
Based on new Infrared Space Observatory midinfrared observations and ground-based Hα and near-infrared observations, we report the detection of a bright starburst in the intragroup medium (IGM) of the famous compact group of galaxies known as Stephan's Quintet (source A in Fig. 1). We demonstrate that this starburst is caused by a collision between a high-velocity (δV~1000 km s-1) intruder galaxy (NGC 7318b) and the IGM of the group. While this is the only starburst known today that is induced by a galaxy/cold intergalactic medium collision, it provides new constraints to the theory for interaction-induced starbursts and may hint at a new mechanism for the star formation excess seen in more distant clusters.
Based on observations made with the Infrared Space Observatory, an ESA project with instruments funded by ESA Member States and with the participation of ISAS and NASA.- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1999
- DOI:
- 10.1086/306771
- arXiv:
- arXiv:astro-ph/9808344
- Bibcode:
- 1999ApJ...512..178X
- Keywords:
-
- GALAXIES: ACTIVE;
- GALAXIES: INTERACTIONS;
- GALAXIES: ISM;
- GALAXIES: STARBURST;
- INFRARED: GALAXIES;
- GALAXIES: INTERGALACTIC MEDIUM;
- Galaxies: Active;
- Galaxies: Interactions;
- Galaxies: ISM;
- Galaxies: Starburst;
- Infrared: Galaxies;
- Galaxies: Intergalactic Medium;
- Astrophysics
- E-Print:
- 17 pages, 2 PS figures. Accepted by ApJ