Molecular component in ram pressure stripped tails of cluster galaxies
Abstract
In recent years, numerous cluster galaxies with tails of ram pressure
stripped (RPS) gas have been discovered, many containing young stars.
These are dramatic examples of galaxy evolution driven by the cluster
environment in which ram pressure of the intracluster medium efficiently
strips star-forming cool interstellar matter (ISM) from infalling
galaxies. Young stars are found in the RPS tails at distances of up to
several tens of kpc, indicating that they have formed in situ in the
tails. Tails of “jellyfish” galaxies are multiphase, containing gas with
a wide range of densities and temperatures. They have been detected in
X-rays, Halpha, and HI. Recently, a cold molecular gas component was
detected in several tails out to large “intracluster” distances from the
galaxies. In some cases, the molecular component was found to form an
important or even dominant fraction of the tail gas mass. We have
observed the molecular component of several RPS tails both with
single-dish antennas and interferometers. I’ll present our APEX, IRAM
and ALMA observations and discuss the incidence and properties of the
molecular component, as well as the efficiency of star formation in the
RPS tails.