Where has all the neutral hydrogen gone?
Astrophysics
2016-01-27 v1
Abstract
Our extremely deep survey for extragalactic HI (HIDEEP) finds no intergalactic gas clouds, and no galaxies with HI at inferred global column-densities below 10^20 cm^-2 when we could have detected such objects down to a completeness limit of 4 x 10^18 cm^-2. We speculate that low surface-density hydrogen is either ionised or locked up in ``frozen discs'', i.e. structures where the local Ly-alpha is insufficient to excite the 21-cm transition to a spin-temperature above the cosmic background. Such ``frozen discs'' might be responsible for many QSOALSs.
Keywords
Cite
@article{arxiv.astro-ph/0211288,
title = {Where has all the neutral hydrogen gone?},
author = {M. J. Disney and R. F. Minchin},
journal= {arXiv preprint arXiv:astro-ph/0211288},
year = {2016}
}
Comments
6 pages, 3 figures, to be published in the proceedings of "The IGM/Galaxy Connection"