Oral Presentation

An ALMA view of NGC 4522, a ram pressure stripped Virgo spiral

Author(s): Bumhyun Lee (Yonsei University) and Aeree Chung (Yonsei University)

Presenter: Bumhyun Lee (Yonsei University)

Ram pressure stripping (RPS) due to the intracluster medium (ICM) is an important mechanism that can have a great impact on galaxy evolution in the cluster environment. RPS can remove cool gas contents as seen in many high-resolution HI observations, which can affect the evolution of galaxies. While it is still under debate whether cold molecular gas of higher density can be also stripped or not, we find clear evidence in our Submillimeter Array (SMA) data of Virgo galaxies undergoing active RPS that molecular gas is disturbed in similar ways as atomic gas inside the stellar disk. Our results imply that the impact of ICM pressure reaches quite deep inside of the galaxy close to the center. In order to better understand how the change of molecular gas modifies star formation activities we followed up one of the best examples with disturbed molecular gas in the Virgo cluster – NGC 4522, using the Atacama Large Millimeter Array (ALMA). In this talk, we will present the results of the SMA data and the ALMA data of Virgo galaxies with clear signs of molecular gas being influenced by the ICM. In particular, we report the detection of extragalactic 13CO discovered in NGC 4522, the first case known to date.