TY - JOUR
T1 - Westerbork Ultra-Deep Survey of HI at z=0.2
AU - Verheijen, Marc
AU - Deshev, Boris
AU - van Gorkom, Jacqueline
AU - Poggianti, Bianca
AU - Chung, Aeree
AU - Cybulski, Ryan
AU - Dwarakanath, K. S.
AU - Montero-Castano, Maria
AU - Morrison, Glenn
AU - Schiminovich, David
AU - Szomoru, Arpad
AU - Yun, Min
PY - 2010/9/1
Y1 - 2010/9/1
N2 - In this contribution, we present some preliminary observational results
from the completed ultra-deep survey of 21cm emission from neutral
hydrogen at redshifts z=0.164-0.224 with the Westerbork Synthesis Radio
Telescope. In two separate fields, a total of 160 individual galaxies
has been detected in neutral hydrogen, with HI masses varying from
1.1x10^9 to 4.0x10^10 Msun. The largest galaxies are spatially resolved
by the synthesized beam of 23x37 arcsec^2 while the velocity resolution
of 19 km/s allowed the HI emission lines to be well resolved. The large
scale structure in the surveyed volume is traced well in HI, apart from
the highest density regions like the cores of galaxy clusters. All
significant HI detections have obvious or plausible optical counterparts
which are usually blue late-type galaxies that are UV-bright. One of the
observed fields contains a massive Butcher-Oemler cluster but none of
the associated blue galaxies has been detected in HI. The data suggest
that the lower-luminosity galaxies at z=0.2 are more gas-rich than
galaxies of similar luminosities at z=0, pending a careful analysis of
the completeness near the detection limit. Optical counterparts of the
HI detected galaxies are mostly located in the 'blue cloud' of the
galaxy population although several galaxies on the 'red sequence' are
also detected in HI. These results hold great promise for future deep
21cm surveys of neutral hydrogen with MeerKAT, APERTIF, ASKAP, and
ultimately the Square Kilometre Array.
AB - In this contribution, we present some preliminary observational results
from the completed ultra-deep survey of 21cm emission from neutral
hydrogen at redshifts z=0.164-0.224 with the Westerbork Synthesis Radio
Telescope. In two separate fields, a total of 160 individual galaxies
has been detected in neutral hydrogen, with HI masses varying from
1.1x10^9 to 4.0x10^10 Msun. The largest galaxies are spatially resolved
by the synthesized beam of 23x37 arcsec^2 while the velocity resolution
of 19 km/s allowed the HI emission lines to be well resolved. The large
scale structure in the surveyed volume is traced well in HI, apart from
the highest density regions like the cores of galaxy clusters. All
significant HI detections have obvious or plausible optical counterparts
which are usually blue late-type galaxies that are UV-bright. One of the
observed fields contains a massive Butcher-Oemler cluster but none of
the associated blue galaxies has been detected in HI. The data suggest
that the lower-luminosity galaxies at z=0.2 are more gas-rich than
galaxies of similar luminosities at z=0, pending a careful analysis of
the completeness near the detection limit. Optical counterparts of the
HI detected galaxies are mostly located in the 'blue cloud' of the
galaxy population although several galaxies on the 'red sequence' are
also detected in HI. These results hold great promise for future deep
21cm surveys of neutral hydrogen with MeerKAT, APERTIF, ASKAP, and
ultimately the Square Kilometre Array.
KW - Astrophysics - Cosmology and Extragalactic Astrophysics
M3 - Article
VL - 1009
SP - 279
JO - ArXiv
JF - ArXiv
ER -