dc.contributor.author Kimm, T dc.contributor.author Haehnelt, M dc.contributor.author Blaizot, J dc.contributor.author Katz, H dc.contributor.author Michel-Dansac, L dc.contributor.author Garel, T dc.contributor.author Rosdahl, J dc.contributor.author Teyssier, R dc.date.accessioned 2018-03-26T09:54:11Z dc.date.available 2018-03-26T09:54:11Z dc.date.issued 2018 dc.identifier.issn 0035-8711 dc.identifier.uri https://www.repository.cam.ac.uk/handle/1810/274331 dc.description.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 $10^{10}\,M_\odot$ halo, we show that the momentum transferred from resonantly scattered Lyman-$\alpha$ (Lya) photons is an important source of stellar feedback which can shape the evolution of galaxies. We find that Lya 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 Lya 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 $\sim 5$, compared to the model without the early feedback. More importantly, we find that galactic outflows become weaker in the presence of strong Lya 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 $\sim5-10$ near the mid plane, while it is reduced to $\sim1$ 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 Lya feedback. dc.publisher Oxford University Press (OUP) dc.title Impact of Lyman alpha pressure on metal-poor dwarf galaxies dc.type Article prism.endingPage 4635 prism.issueIdentifier 4 prism.publicationDate 2018 prism.publicationName Monthly Notices of the Royal Astronomical Society prism.startingPage 4617 prism.volume 475 dc.identifier.doi 10.17863/CAM.21452 dcterms.dateAccepted 2018-01-10 rioxxterms.versionofrecord 10.1093/mnras/sty126 rioxxterms.version AM rioxxterms.licenseref.uri http://www.rioxx.net/licenses/all-rights-reserved rioxxterms.licenseref.startdate 2018-04-21 dc.contributor.orcid Haehnelt, Martin [0000-0001-8443-2393] dc.identifier.eissn 1365-2966 dc.publisher.url http://dx.doi.org/10.1093/mnras/sty126 rioxxterms.type Journal Article/Review pubs.funder-project-id European Research Council (320596) pubs.funder-project-id Science and Technology Facilities Council (ST/N000927/1) cam.issuedOnline 2018-01-15 rioxxterms.freetoread.startdate 2019-01-15
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