Measuring Cosmic Density of Neutral Hydrogen via Stacking the DINGO-VLA
  Data
  We use the 21 cm emission line data from the DINGO-VLA project to study the
atomic hydrogen gas H\,{\textsc i} of the Universe at redshifts $z<0.1$.
Results are obtained using a stacking analysis, combining the H\,{\textsc 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 dataset. 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 $30\sigma$ H\,{\textsc i} mass
measurement from the stacked spectrum, indicating an average H\,{\textsc i}
mass of $M_{\rm H\,{\textsc i}}=(1.674\pm 0.183)\times 10^{9}~{\Msun}$. The
corresponding cosmic density of neutral atomic hydrogen is $\Omega_{\rm
H\,{\textsc i}}=(0.377\pm 0.042)\times 10^{-3}$ at redshift of $z=0.051$. These
values are in good agreement with earlier results, implying there is no
significant evolution of $\Omega_{\rm H\,{\textsc i}}$ at lower redshifts.
