Regan, John and Downes, Turlough P. (2018) Fragmentation inside atomic cooling haloes exposed to Lyman-Werner radiation. Monthly Notices of the Royal Astronomical Society, 475 (4). pp. 4636-4647. ISSN 1365-2966
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Abstract
Supermassive stars born in pristine environments in the early Universe hold the promise of
being the seeds for the supermassive black holes observed as high redshift quasars shortly
after the epoch of reionisation. H2 suppression is thought to be crucial in order to negate
normal Population III star formation and allow high accretion rates to drive the formation of
supermassive stars. Only in the cases where vigorous fragmentation is avoided will a monolithic collapse be successful giving rise to a single massive central object. We investigate the
number of fragmentation sites formed in collapsing atomic cooling haloes subject to various
levels of background Lyman-Werner flux. The background Lyman-Werner flux manipulates
the chemical properties of the gas in the collapsing halo by destroying H2. We find that only
when the collapsing gas cloud shifts from the molecular to the atomic cooling regime is the
degree of fragmentation suppressed. In our particular case we find that this occurs above a
critical Lyman-Werner background of J ∼ 10 J21. The important criterion being the transition
to the atomic cooling regime rather than the actual value of J, which will vary locally. Once
the temperature of the gas exceeds T & 104 K and the gas transitions to atomic line cooling,
then vigorous fragmentation is strongly suppressed.
Item Type: | Article |
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Keywords: | Cosmology; theory; large-scale structure; first stars; methods; numerical; |
Academic Unit: | Faculty of Science and Engineering > Theoretical Physics Faculty of Science and Engineering > Research Institutes > Hamilton Institute |
Item ID: | 13183 |
Depositing User: | John Regan |
Date Deposited: | 07 Aug 2020 20:25 |
Journal or Publication Title: | Monthly Notices of the Royal Astronomical Society |
Publisher: | The Royal Astronomical Society |
Refereed: | Yes |
Related URLs: | |
URI: | https://mural.maynoothuniversity.ie/id/eprint/13183 |
Use Licence: | This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here |
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