Evidence for H I replenishment in massive galaxies through gas accretion from the cosmic web
Date Issued
2017
Author(s)
Abstract
We examine the H I-to-stellar mass ratio (H I fraction) for galaxies near filament backbones within the nearby Universe (d < 181 Mpc). This work uses the 6-degree Field Galaxy Survey and the Discrete Persistent Structures Extractor to define the filamentary structure of the local cosmic web. H I spectral stacking of H I Parkes all sky survey observations yields the H I fraction for filament galaxies and a field control sample. The H I fraction is measured for different stellar masses and fifth nearest neighbour projected densities (Σ5) to disentangle what influences cold gas in galaxies. For galaxies with stellar masses log(M⋆) ≤ 11 M☉ in projected densities 0 ≤ Σ5 < 3 galaxies Mpc-2, all H I fractions of galaxies near filaments are statistically indistinguishable from the control sample. Galaxies with stellar masses log(M⋆) ≥ 11 M☉ have a systematically higher H I fraction near filaments than the control sample. The greatest difference is 0.75 dex, which is 5.5σ difference at mean projected densities of 1.45 galaxies Mpc-2. We suggest that this is evidence for massive galaxies accreting cold gas from the intrafilament medium that can replenish some H I gas. This supports cold mode accretion where filament galaxies with a large gravitational potential can draw gas from the large-scale structure.
Volume
466
Issue
4
Start page
4692
Issn Identifier
0035-8711
Ads BibCode
2017MNRAS.466.4692K
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
stw3328_compressed.pdf
Description
Pdf editoriale
Size
809.78 KB
Format
Adobe PDF
Checksum (MD5)
1312c24ac5d839ee3c78a24b70b3047f