Discovery of ram-pressure stripped gas around an elliptical galaxy in Abell 2670

 Studies of cluster galaxies are increasingly finding galaxies with spectacular one-sided tails of gas and young stars, suggestive of intense ram-pressure stripping. These so-called “jellyfish” galaxies typically have late-type morphology. In this talk, we present Multi Unit Spectroscopic Explorer (MUSE) observations of an elliptical galaxy in Abell 2670 with long tails of material visible in the optical spectra, as well as blobs with tadpole-like morphology (Sheen et al. 2017). The spectra in the central part of the galaxy reveal a stellar component as well as ionized gas. The stellar component does not have significant rotation, while the ionized gas defines a clear star-forming gas disk. We argue, based on deep optical images of the galaxy, that the gas was most likely acquired during a past wet merger. It is possible that the star-forming blobs are also remnants of the merger. In addition, the direction and kinematics of the one-sided ionized tails, combined with the tadpole morphology of the star-forming blobs, strongly suggests that the system is undergoing ram pressure from the intracluster medium. We will also discuss about the emission line diagnostics from the MUSE spectra and star formation rates based on the multiwavelength data. In summary, this talk presents the discovery of a post-merger elliptical galaxy undergoing ram-pressure stripping. 

Speaker: 
Yun-Kyeon Sheen
Location: 
DoA, Rm 2907
Time: 
Mon, 2017-10-30 12:00 to 13:00