Joo Heon Yoon, Mary Putman
The effect of environment on the circumgalactic medium (CGM) is investigated through a comparison of Lya absorption line data in the Virgo Cluster and the field. This paper uses the first systematic survey of background QSOs in and around the Virgo Cluster and large existing surveys of galaxies at low redshift. While previous studies found denser gas (higher equivalent width) closer to a galaxy (lower impact parameter), this correlation disappears in the Virgo environment. In addition, the covering fraction of the CGM is lower in the cluster environment than in the circumcluster environment and field. The results indicate the CGM is suppressed for cluster galaxies while galaxies in the circumcluster environment have abundant CGM. The truncation of the CGM may result in the quenching of star formation through starvation. Our results also show that CGM surveys need to consider the role of environment.
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http://arxiv.org/abs/1307.2235
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