The large- and small-scale properties of the intergalactic gas in the Slug Lyα nebula revealed by MUSE He II emission observations
Deep MUSE He II observations of the Slug Lyα nebula point to intergalactic gas that is clumpy and spread over very large distances along the line of sight.
What was found
- Extended He II emission is detected over about 100 kpc, only in regions tied to bright Lyα emission and a continuum-detected source, with sharp changes in line ratios between neighbouring regions.
- The abrupt changes in He II/Lyα probably reflect large differences in physical distance from the quasar, supported by new Hα detections and Lyα velocity shifts.
- If so, the emitting structure could span scales up to a megaparsec and lie mostly along our line of sight.
- The low He II/Lyα values imply a broad gas density distribution, similar in width to the ones in galactic interstellar media, so intergalactic gas at high redshift appears highly clumpy and multiphase on scales below the current resolution of a few physical kpc.
This summary is written for a general audience. The paper has the full details.
Cite this paper
Cantalupo, S., et al. 2019, MNRAS, 483, 5188–5204, doi:10.1093/mnras/sty3481
@article{cantalupo2019,
author = {Cantalupo, Sebastiano and others},
title = {{The large- and small-scale properties of the intergalactic gas in the Slug Lyα nebula revealed by MUSE He II emission observations}},
journal = {Monthly Notices of the Royal Astronomical Society},
year = {2019},
volume = {483},
pages = {5188--5204},
doi = {10.1093/mnras/sty3481},
eprint = {1811.11783},
archivePrefix = {arXiv}
}