The photoheating of the intergalactic medium in synthesis models of the UV background
We compare cosmological hydrodynamical simulations combined with the homogeneous metagalactic UV background (UVB) of Haardt & Madau (2012) (HM2012) to observations of the Lyman-alpha forest that are sensitive to the thermal and ionization state of the intergalactic medium (IGM). The transition f...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Published: |
Oxford University Press
2015
|
| Subjects: | |
| Online Access: | https://eprints.nottingham.ac.uk/34607/ |
| _version_ | 1848794893007192064 |
|---|---|
| author | Puchwein, Ewald Bolton, James S. Haehnelt, Martin G. Madau, Piero Becker, George D. Haardt, Francesco |
| author_facet | Puchwein, Ewald Bolton, James S. Haehnelt, Martin G. Madau, Piero Becker, George D. Haardt, Francesco |
| author_sort | Puchwein, Ewald |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | We compare cosmological hydrodynamical simulations combined with the homogeneous metagalactic UV background (UVB) of Haardt & Madau (2012) (HM2012) to observations of the Lyman-alpha forest that are sensitive to the thermal and ionization state of the intergalactic medium (IGM). The transition from optically thick to thin photoheating predicted by the simple one-zone, radiative transfer model implemented by HM2012 predicts a thermal history that is in remarkably good agreement with the observed rise of the IGM temperature at z~3 if we account for the expected evolution of the volume filling factor of HeIII. Our simulations indicate that there may be, however, some tension between the observed peak in the temperature evolution and the rather slow evolution of the HeII opacities suggested by recent Hubble Space Telescope/COS measurements. The HM2012 UVB also underpredicts the metagalactic hydrogen photoionization rate required by our simulations to match the observed opacity of the forest at z>4 and z<2. |
| first_indexed | 2025-11-14T19:23:25Z |
| format | Article |
| id | nottingham-34607 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:23:25Z |
| publishDate | 2015 |
| publisher | Oxford University Press |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-346072024-08-15T15:17:15Z https://eprints.nottingham.ac.uk/34607/ The photoheating of the intergalactic medium in synthesis models of the UV background Puchwein, Ewald Bolton, James S. Haehnelt, Martin G. Madau, Piero Becker, George D. Haardt, Francesco We compare cosmological hydrodynamical simulations combined with the homogeneous metagalactic UV background (UVB) of Haardt & Madau (2012) (HM2012) to observations of the Lyman-alpha forest that are sensitive to the thermal and ionization state of the intergalactic medium (IGM). The transition from optically thick to thin photoheating predicted by the simple one-zone, radiative transfer model implemented by HM2012 predicts a thermal history that is in remarkably good agreement with the observed rise of the IGM temperature at z~3 if we account for the expected evolution of the volume filling factor of HeIII. Our simulations indicate that there may be, however, some tension between the observed peak in the temperature evolution and the rather slow evolution of the HeII opacities suggested by recent Hubble Space Telescope/COS measurements. The HM2012 UVB also underpredicts the metagalactic hydrogen photoionization rate required by our simulations to match the observed opacity of the forest at z>4 and z<2. Oxford University Press 2015-07-11 Article PeerReviewed Puchwein, Ewald, Bolton, James S., Haehnelt, Martin G., Madau, Piero, Becker, George D. and Haardt, Francesco (2015) The photoheating of the intergalactic medium in synthesis models of the UV background. Monthly Notices of the Royal Astronomical Society, 450 (4). pp. 4081-4097. ISSN 1365-2966 Radiative Transfer Methods: Numerical Intergalactic Medium Quasars Absorption Lines Cosmology: Theory http://mnras.oxfordjournals.org/content/450/4/4081 doi:10.1093/mnras/stv773 doi:10.1093/mnras/stv773 |
| spellingShingle | Radiative Transfer Methods: Numerical Intergalactic Medium Quasars Absorption Lines Cosmology: Theory Puchwein, Ewald Bolton, James S. Haehnelt, Martin G. Madau, Piero Becker, George D. Haardt, Francesco The photoheating of the intergalactic medium in synthesis models of the UV background |
| title | The photoheating of the intergalactic medium in synthesis models of the UV background |
| title_full | The photoheating of the intergalactic medium in synthesis models of the UV background |
| title_fullStr | The photoheating of the intergalactic medium in synthesis models of the UV background |
| title_full_unstemmed | The photoheating of the intergalactic medium in synthesis models of the UV background |
| title_short | The photoheating of the intergalactic medium in synthesis models of the UV background |
| title_sort | photoheating of the intergalactic medium in synthesis models of the uv background |
| topic | Radiative Transfer Methods: Numerical Intergalactic Medium Quasars Absorption Lines Cosmology: Theory |
| url | https://eprints.nottingham.ac.uk/34607/ https://eprints.nottingham.ac.uk/34607/ https://eprints.nottingham.ac.uk/34607/ |