Measuring cosmic density of neutral hydrogen via stacking the DINGO-VLA data. Issue 2 (2nd October 2021)

• Record Type: Journal Article
• Authors: Chen, Qingxiang; Meyer, Martin; Popping, Attila; Staveley-Smith, Lister; Bryant, Julia; Delhaize, Jacinta; Holwerda, B W; Cluver, M E; Loveday, J; Lopez-Sanchez, Angel R; Zwaan, Martin; Taylor, E N; Hopkins, A M; Wright, Angus; Driver, Simon; Brough, S
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 508:Issue 2(2021)
• Page Start: 2758
• Page End: 2770
• Publication Date: 2021-10-02
• Subjects: ISM: atoms -- galaxies: star formation -- radio lines: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab2810
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: 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 ${\rm{M_{\rm{{H}\, \small{I}}}}}=(1.67\pm 0.18)\times 10^{9}~{\rm{{\rm M}_{\odot }}}$ . The corresponding cosmic density of neutral atomic hydrogen is ${\rm{\Omega _{\rm{{H}\, \small{I}}}}}=(0.38\pm 0.04)\times 10^{-3}$ at redshift of z = 0.051. These values are in good agreement with earlier results, implying there is no significant evolution of $\Omega _{\rm{{H}\, \small{I}}}$ at lower redshifts.