Presentation #241.24 in the session Evolution of Galaxies — iPoster Session.
Observations of the galaxy population throughout the cosmic time have suggested an evolution scenario where galaxies evolve from blue and star-forming, to red and quiescent as star formation is quenched and gas is consumed in stars or becomes unavailable for stellar synthesis. Though multiple mechanisms have been shown to be able to quench galaxies in different ways, the interplay and relative importance of these mechanisms are still not fully understood. In this work, we study a particular quenching galaxy: IC 860, for which we have exquisite multiwavelength data to probe different activities such as outflows and AGN in the galaxy. IC 860 is a quenching galaxy at a very early stage and is therefore an ideal case study for understanding the triggers of quenching. We find a multiphase outflow in molecular and neutral gas that seems unable to escape the galaxy. We also find evidence for a recent merger and a buried AGN. The depletion time of the molecular gas reservoir under the current star formation rate is ~7 Gyr, indicating that the galaxy could stay at the intermediate stage between the blue and red sequence for a long time. Thus the timescales for quenching and gas depletion are not necessarily the same. The outflow is likely driven by the AGN given the low recent star formation rate. Our analysis supports the quenching picture where outflows help suppress star formation by disturbing rather than expelling the gas and shed light on possible on-going activities in similar quenching galaxies.