Impact of Lyman alpha pressure on metal-poor dwarf galaxies

Taysun Kimm, Martin Haehnelt, Jérémy Blaizot, Harley Katz, Léo Michel-Dansac, Thibault Garel, Joakim Rosdahl, Romain Teyssier

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Understanding the origin of strong galactic outflows and the suppression of star formation in dwarf galaxies is a key problem in galaxy formation. Using a set of radiation-hydrodynamic simulations of an isolated dwarf galaxy embedded in a 10 10 M⊙ halo, we show that the momentum transferred from resonantly scattered Lyman-a (Lyα) photons is an important source of stellar feedback which can shape the evolution of galaxies. We find that Lyα feedback suppresses star formation by a factor of two in metal-poor galaxies by regulating the dynamics of star-forming clouds before the onset of supernova explosions (SNe). This is possible because each Lyα photon resonantly scatters and imparts ~10-300 times greater momentum than in the single scattering limit. Consequently, the number of star clusters predicted in the simulations is reduced by a factor of ~5, compared to the model without the early feedback. More importantly, we find that galactic outflows become weaker in the presence of strong Lyα radiation feedback, as star formation and associated SNe become less bursty. We also examine a model in which radiation field is arbitrarily enhanced by a factor of up to 10, and reach the same conclusion. The typical mass-loading factors in our metal-poor dwarf system are estimated to be ~5-10 near the mid-plane, while it is reduced to ~1 at larger radii. Finally, we find that the escape of ionizing radiation and hence the reionization history of the Universe is unlikely to be strongly affected by Lyα feedback.

Original languageEnglish
Pages (from-to)4617-4635
Number of pages19
JournalMonthly Notices of the Royal Astronomical Society
Volume475
Issue number4
DOIs
Publication statusPublished - 2018 Apr 21

Fingerprint

dwarf galaxies
explosion
metal
momentum
outflow
star formation
metals
supernovae
explosions
simulation
galaxies
hydrodynamics
scattering
photons
star clusters
galactic evolution
radiation
ionizing radiation
radiation distribution
escape

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Kimm, T., Haehnelt, M., Blaizot, J., Katz, H., Michel-Dansac, L., Garel, T., ... Teyssier, R. (2018). Impact of Lyman alpha pressure on metal-poor dwarf galaxies. Monthly Notices of the Royal Astronomical Society, 475(4), 4617-4635. https://doi.org/10.1093/mnras/sty126
Kimm, Taysun ; Haehnelt, Martin ; Blaizot, Jérémy ; Katz, Harley ; Michel-Dansac, Léo ; Garel, Thibault ; Rosdahl, Joakim ; Teyssier, Romain. / Impact of Lyman alpha pressure on metal-poor dwarf galaxies. In: Monthly Notices of the Royal Astronomical Society. 2018 ; Vol. 475, No. 4. pp. 4617-4635.
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Kimm, T, Haehnelt, M, Blaizot, J, Katz, H, Michel-Dansac, L, Garel, T, Rosdahl, J & Teyssier, R 2018, 'Impact of Lyman alpha pressure on metal-poor dwarf galaxies', Monthly Notices of the Royal Astronomical Society, vol. 475, no. 4, pp. 4617-4635. https://doi.org/10.1093/mnras/sty126

Impact of Lyman alpha pressure on metal-poor dwarf galaxies. / Kimm, Taysun; Haehnelt, Martin; Blaizot, Jérémy; Katz, Harley; Michel-Dansac, Léo; Garel, Thibault; Rosdahl, Joakim; Teyssier, Romain.

In: Monthly Notices of the Royal Astronomical Society, Vol. 475, No. 4, 21.04.2018, p. 4617-4635.

Research output: Contribution to journalArticle

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AU - Haehnelt, Martin

AU - Blaizot, Jérémy

AU - Katz, Harley

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AU - Garel, Thibault

AU - Rosdahl, Joakim

AU - Teyssier, Romain

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