Star-forming filaments in warm dark matter models
Gao, L.; Theuns, T.; Springel, V.
Professor Tom Theuns email@example.com
We performed a hydrodynamical cosmological simulation of the formation of a Milky Way-like galaxy in a warm dark matter (WDM) cosmology. Smooth and dense filaments, several comoving mega parsec long, form generically above z ∼ 2 in this model. Atomic line cooling allows gas in the centres of these filaments to cool to the base of the cooling function, resulting in a very striking pattern of extended Lyman-limit systems (LLSs). Observations of the correlation function of LLSs might hence provide useful limits on the nature of the dark matter. We argue that the self-shielding of filaments may lead to a thermal instability resulting in star formation. We implement a sub-grid model for this, and find that filaments rather than haloes dominate star formation until z ∼ 6, although this depends on how stars form in WDM. Reionization decreases the gas density in filaments, and the more usual star formation in haloes dominates below z ∼ 6, although star formation in filaments continues until z = 2. 15 per cent of the stars of the z = 0 galaxy formed in filaments. At higher redshift, these stars give galaxies a stringy appearance, which, if observed, might be a strong indication that the dark matter is warm.
Gao, L., Theuns, T., & Springel, V. (2015). Star-forming filaments in warm dark matter models. Monthly Notices of the Royal Astronomical Society, 450(1), 45-52. https://doi.org/10.1093/mnras/stv643
|Journal Article Type||Article|
|Acceptance Date||Mar 24, 2015|
|Publication Date||Jun 11, 2015|
|Deposit Date||Feb 10, 2016|
|Publicly Available Date||Feb 18, 2016|
|Journal||Monthly Notices of the Royal Astronomical Society|
|Publisher||Royal Astronomical Society|
|Peer Reviewed||Peer Reviewed|
|Keywords||Galaxies: formation, Intergalactic medium, Dark matter.|
Published Journal Article
This article has been accepted for publication in Monthly notices of the Royal Astronomical Society ©: 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
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