17th of January 2017 |
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The reversed fHI-density relation in the least-dense environments |
by Jing Wang (CASS) |
It has been known for a long time that
galaxies in denser clustering environments tend to have less gas and star
formation. A recent paper,
Janowiecki et al. 2017, for
the first time shows that galaxies in isolation and small groups do not
follow that general trend. This picture shows that below a stellar mass of
1010.2 Msun, central galaxies of small groups tend to be HI-richer
and with higher specific star formation rate on average than galaxies in
isolation at the same stellar mass. This result reminds us that fuelling and
star formation are as important aspects as stripping and quenching in the group
environments. This is also the first paper based on data of xGASS, an extension
of the GASS survey to a
lower stellar mass limit of 109 Msun. Reference: Steven Janowiecki, Barbara Catinella, Luca Cortese, Amelie Saintonge, Toby Brown, and Jing Wang 2017, MNRAS, accepted (astro-ph). |