Publication Date:
2021-10-02
Description:
We use the 21-cm emission-line data from the Deep Investigation of Neutral Gas Origin-Very Large Array (DINGO-VLA) project to study the atomic hydrogen gas H i of the Universe at redshifts z 〈 0.1. Results are obtained using a stacking analysis, combining the H i signals from 3622 galaxies extracted from 267 VLA pointings in the G09 field of the Galaxy and Mass Assembly Survey (GAMA). Rather than using a traditional one-dimensional spectral stacking method, a three-dimensional cubelet stacking method is used to enable deconvolution and the accurate recovery of average galaxy fluxes from this high-resolution interferometric data set. By probing down to galactic scales, this experiment also overcomes confusion corrections that have been necessary to include in previous single-dish studies. After stacking and deconvolution, we obtain a 30σ H i mass measurement from the stacked spectrum, indicating an average H i mass of ${
m{M_{
m{{H},small{I}}}}}=(1.67pm 0.18)imes 10^{9}~{
m{{
m M}_{odot }}}$. The corresponding cosmic density of neutral atomic hydrogen is ${
m{Omega _{
m{{H},small{I}}}}}=(0.38pm 0.04)imes 10^{-3}$ at redshift of z = 0.051. These values are in good agreement with earlier results, implying there is no significant evolution of $Omega _{
m{{H},small{I}}}$ at lower redshifts.
Print ISSN:
0035-8711
Electronic ISSN:
1365-2966
Topics:
Physics
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