TY - JOUR
T1 - xGASS: gas-rich central galaxies in small groups and their connections to cosmic web gas feeding
AU - Janowiecki, Steven
AU - Catinella, Barbara
AU - Cortese, Luca
AU - Saintonge, Amélie
AU - Brown, Tobias
AU - Wang, Jing
PY - 2017/4/1
Y1 - 2017/4/1
N2 - We use deep H i observations obtained as part of the extended GALEX
Arecibo SDSS survey (xGASS) to study the cold gas properties of central
galaxies across environments. We find that below stellar masses of
1010.2 M⊙, central galaxies in groups have an
average atomic hydrogen gas fraction ∼0.3 dex higher than those in
isolation at the same stellar mass. At these stellar masses, group
central galaxies are usually found in small groups of N = 2 members. The
higher H i content in these low-mass group central galaxies is mirrored
by their higher average star formation activity and molecular hydrogen
content. At larger stellar masses, this difference disappears and
central galaxies in groups have similar (or even smaller) gas reservoirs
and star formation activity compared to those in isolation. We discuss
possible scenarios able to explain our findings and suggest that the
higher gas content in low-mass group central galaxies is likely due to
the contributions from the cosmic web or H i-rich minor mergers, which
also fuel their enhanced star formation activity.
AB - We use deep H i observations obtained as part of the extended GALEX
Arecibo SDSS survey (xGASS) to study the cold gas properties of central
galaxies across environments. We find that below stellar masses of
1010.2 M⊙, central galaxies in groups have an
average atomic hydrogen gas fraction ∼0.3 dex higher than those in
isolation at the same stellar mass. At these stellar masses, group
central galaxies are usually found in small groups of N = 2 members. The
higher H i content in these low-mass group central galaxies is mirrored
by their higher average star formation activity and molecular hydrogen
content. At larger stellar masses, this difference disappears and
central galaxies in groups have similar (or even smaller) gas reservoirs
and star formation activity compared to those in isolation. We discuss
possible scenarios able to explain our findings and suggest that the
higher gas content in low-mass group central galaxies is likely due to
the contributions from the cosmic web or H i-rich minor mergers, which
also fuel their enhanced star formation activity.
KW - galaxies: evolution
KW - galaxies: fundamental parameters
KW - galaxies: groups: general
KW - galaxies: star formation
KW - radio lines: galaxies
KW - ultraviolet: galaxies
U2 - 10.1093/mnras/stx046
DO - 10.1093/mnras/stx046
M3 - Article
VL - 466
SP - 4795
EP - 4812
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -