Diagnosing galactic feedback with line broadening in the low redshift Lyα forest
We compare the low-redshift (z 0.1) Lyα forest from hydrodynamical simulations with data from the Cosmic Origins Spectrograph. We find the tension between the observed number of lines with b-parameters in the range of 25–45 km s−1 and the predictions from simulations that incorporate either vigorou...
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| Format: | Article |
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Oxford University Press
2017
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| Online Access: | https://eprints.nottingham.ac.uk/42519/ |
| _version_ | 1848796505838714880 |
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| author | Viel, Matteo Haehnelt, Martin G. Bolton, James S. Kim, Tae-Sun Puchwein, Ewald Nasir, Fahad Wakker, Bart P. |
| author_facet | Viel, Matteo Haehnelt, Martin G. Bolton, James S. Kim, Tae-Sun Puchwein, Ewald Nasir, Fahad Wakker, Bart P. |
| author_sort | Viel, Matteo |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | We compare the low-redshift (z 0.1) Lyα forest from hydrodynamical simulations with data from the Cosmic Origins Spectrograph. We find the tension between the observed number of lines with b-parameters in the range of 25–45 km s−1 and the predictions from simulations that incorporate either vigorous feedback from active galactic nuclei or that exclude feedback altogether. The gas in these simulations is, respectively, either too hot to contribute to the Lyα absorption or too cold to produce the required linewidths. Matching the observed b parameter distribution therefore requires feedback processes that thermally or turbulently broaden the absorption features without collisionally (over)ionizing hydrogen. This suggests that the Lyα forest b-parameter distribution is a valuable diagnostic of galactic feedback in the low-redshift Universe. We furthermore confirm that the low-redshift Lyα forest column density distribution is better reproduced by an ultraviolet background with the H I photoionization rate a factor of 1.5–3 higher than predicted by Haardt and Madau. |
| first_indexed | 2025-11-14T19:49:03Z |
| format | Article |
| id | nottingham-42519 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:49:03Z |
| publishDate | 2017 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-425192020-05-04T18:31:06Z https://eprints.nottingham.ac.uk/42519/ Diagnosing galactic feedback with line broadening in the low redshift Lyα forest Viel, Matteo Haehnelt, Martin G. Bolton, James S. Kim, Tae-Sun Puchwein, Ewald Nasir, Fahad Wakker, Bart P. We compare the low-redshift (z 0.1) Lyα forest from hydrodynamical simulations with data from the Cosmic Origins Spectrograph. We find the tension between the observed number of lines with b-parameters in the range of 25–45 km s−1 and the predictions from simulations that incorporate either vigorous feedback from active galactic nuclei or that exclude feedback altogether. The gas in these simulations is, respectively, either too hot to contribute to the Lyα absorption or too cold to produce the required linewidths. Matching the observed b parameter distribution therefore requires feedback processes that thermally or turbulently broaden the absorption features without collisionally (over)ionizing hydrogen. This suggests that the Lyα forest b-parameter distribution is a valuable diagnostic of galactic feedback in the low-redshift Universe. We furthermore confirm that the low-redshift Lyα forest column density distribution is better reproduced by an ultraviolet background with the H I photoionization rate a factor of 1.5–3 higher than predicted by Haardt and Madau. Oxford University Press 2017-01-11 Article PeerReviewed Viel, Matteo, Haehnelt, Martin G., Bolton, James S., Kim, Tae-Sun, Puchwein, Ewald, Nasir, Fahad and Wakker, Bart P. (2017) Diagnosing galactic feedback with line broadening in the low redshift Lyα forest. Monthly Notices of the Royal Astronomical Society, 467 (1). L86-L90. ISSN 1365-2966 methods: numerical intergalactic medium quasars: absorption lines diffuse radiation large-scale structure of Universe https://academic.oup.com/mnrasl/article-lookup/doi/10.1093/mnrasl/slx004 doi:10.1093/mnrasl/slx004 doi:10.1093/mnrasl/slx004 |
| spellingShingle | methods: numerical intergalactic medium quasars: absorption lines diffuse radiation large-scale structure of Universe Viel, Matteo Haehnelt, Martin G. Bolton, James S. Kim, Tae-Sun Puchwein, Ewald Nasir, Fahad Wakker, Bart P. Diagnosing galactic feedback with line broadening in the low redshift Lyα forest |
| title | Diagnosing galactic feedback with line broadening in the low redshift Lyα forest |
| title_full | Diagnosing galactic feedback with line broadening in the low redshift Lyα forest |
| title_fullStr | Diagnosing galactic feedback with line broadening in the low redshift Lyα forest |
| title_full_unstemmed | Diagnosing galactic feedback with line broadening in the low redshift Lyα forest |
| title_short | Diagnosing galactic feedback with line broadening in the low redshift Lyα forest |
| title_sort | diagnosing galactic feedback with line broadening in the low redshift lyα forest |
| topic | methods: numerical intergalactic medium quasars: absorption lines diffuse radiation large-scale structure of Universe |
| url | https://eprints.nottingham.ac.uk/42519/ https://eprints.nottingham.ac.uk/42519/ https://eprints.nottingham.ac.uk/42519/ |