Skip to main content

Research Repository

Advanced Search

Star-forming filaments in warm dark matter models

Gao, L.; Theuns, T.; Springel, V.

Star-forming filaments in warm dark matter models Thumbnail


L. Gao

V. Springel


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.

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
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 450
Issue 1
Pages 45-52
Keywords Galaxies: formation, Intergalactic medium, Dark matter.


Published Journal Article (1.2 Mb)

Copyright Statement
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.

You might also like

Downloadable Citations