We use observations made with the Giant Metrewave Radio Telescope (GMRT) to probe the neutral hydrogen (HI) gas content of field galaxies in the VIMOS VLT Deep Survey (VVDS) 14h field at z~=0.32. Because the HI emission from individual galaxies is too faint to detect at this redshift, we use an HI spectral stacking technique using the known optical positions and redshifts of the 165 galaxies in our sample to co-add their HI spectra and thus obtain the average HI mass of the galaxies. Stacked HI measurements of 165 galaxies show that >~95 per cent of the neutral gas is found in blue, star-forming galaxies. Among these galaxies, those having lower stellar mass are more gas rich than more massive ones. We apply a volume correction to our HI measurement to evaluate the HI gas density at z~=0.32 as {OMETA}_HI_=(0.50+/-0.18)x10^-3^ in units of the cosmic critical density. This value is in good agreement with previous results at z<0.4, suggesting no evolution in the neutral hydrogen gas density over the last ~4Gyr. However the z~=0.32 gas density is lower than that at z~5 by at least a factor of two.
We present the 5 sigma catalogue at 610MHz of the VVDS-VLA deep field obtained from GMRT observations. The field is located at 02:26:00-04:30:00 (J2000) and covers a 1 square degree area. The GMRT observations imaged the whole 1 square degree field with an angular resolution of 6 arcsec and an average sensitivity of about 50 microJy. The catalogue lists 514 radio sources 17 of which are fitted with multiple components.
We use deep near-IR photometry of the VISTA Variables in the Via Lactea (VVV) Survey and deep DECam Plane Survey (DECaPS) optical photometry to confirm the physical reality of the candidate globular cluster (GC) Minni 22, which is located in the Galactic bulge. This object, which was detected as a high density region in our maps of bulge red giants, is now confirmed as a real GC based on the optical and near-IR color-magnitude diagrams. We also recover three known fundamental mode (ab type) RR Lyrae stars within 2 arcmin of the cluster center. The presence of RR Lyrae stars also seems to confirm Minni 22 as a bonafide old and metal-poor GC. We estimate a cluster reddening E(J-Ks)=0.6mag and determine its heliocentric distance D=7.4+/-0.3kpc. The optical and near-IR color-magnitude diagrams reveal well-defined red giant branches in all cases, including a red giant branch bump at Ks=13.30+/-0.05mag. The comparison with theoretical isochrones yields a mean metallicity of [Fe/H]=-1.3+/-0.3dex, and age of t~11.2Gyr. This is a good example of a new low-luminosity (M_V_=-6.2mag) GC found in the central bulge of the Milky Way. After discussing the different ways to confirm the existence of bulge GC candidates, we find that one of the best methods is to use the CMDs from the combination of the DECaPS+VVV photometries.
VVV DR5 - VISTA Variables in the Via Lactea survey
Date:
24 Jan 2022 11:52:51
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VVV survey will perform wide FOV multi-epoch observations of the Galaxy's bulge and part of the disk, providing the astronomical public community with a high resolution 3-D (or 4-D if you include the time dimension) map of the bulge.
VVV DR5 - VISTA Variables in the Via Lactea survey
Date:
24 Jan 2022 11:48:18
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VVV survey will perform wide FOV multi-epoch observations of the Galaxy's bulge and part of the disk, providing the astronomical public community with a high resolution 3-D (or 4-D if you include the time dimension) map of the bulge.
VVV DR4 - VISTA Variables in the Via Lactea survey
Date:
04 Dec 2019 13:43:08
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VVV survey will perform wide FOV multi-epoch observations of the Galaxy's bulge and part of the disk, providing the astronomical public community with a high resolution 3-D (or 4-D if you include the time dimension) map of the bulge.
VVV DR1 - VISTA Variables in the Via Lactea survey
Short Name:
VVV DR1
Date:
04 Dec 2019 13:42:47
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VVV survey will perform wide FOV multi-epoch observations of the Galaxy's bulge and part of the disk, providing the astronomical public community with a high resolution 3-D (or 4-D if you include the time dimension) map of the bulge.
VVV DR4 - VISTA Variables in the Via Lactea survey
Date:
20 Mar 2019 15:41:34
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VVV survey will perform wide FOV multi-epoch observations of the Galaxy's bulge and part of the disk, providing the astronomical public community with a high resolution 3-D (or 4-D if you include the time dimension) map of the bulge.
VVV DR2 - VISTA Variables in the Via Lactea survey
Date:
05 Mar 2014 15:10:06
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VVV survey will perform wide FOV multi-epoch observations of the Galaxy's bulge and part of the disk, providing the astronomical public community with a high resolution 3-D (or 4-D if you include the time dimension) map of the bulge.
VVV DR1 - VISTA Variables in the Via Lactea survey
Date:
17 Jul 2012 15:12:06
Publisher:
WFAU, Institute for Astronomy, University of Edinburgh
Description:
The VVV survey will perform wide FOV multi-epoch observations of the Galaxy's bulge and part of the disk, providing the astronomical public community with a high resolution 3-D (or 4-D if you include the time dimension) map of the bulge.
