1. RRI Digital Repository
  2. 04. Astronomy and Astrophysics
  3. Research Papers (A&A)
Please use this identifier to cite or link to this item: http://hdl.handle.net/2289/4778
Full metadata record
DC FieldValueLanguage
dc.contributor.authorUhlig, M.-
dc.contributor.authorPfrommer, C.-
dc.contributor.authorSharma, Mahavir-
dc.contributor.authorNath, Biman B.-
dc.contributor.authorEnsslin, T.A.-
dc.contributor.authorSpringel, V.-
dc.date.accessioned2012-07-09T05:03:52Z-
dc.date.available2012-07-09T05:03:52Z-
dc.date.issued2012-07-
dc.identifier.citationMonthly Notices of the Royal Astronomical Society, 2012, Vol. 423, p. 2374-2396en
dc.identifier.issn0035-8711-
dc.identifier.issn1365-2966 (Online)-
dc.identifier.urihttp://hdl.handle.net/2289/4778-
dc.descriptionRestricted Access. An open-access version is available at arXiv.org (one of the alternative locations)en
dc.description.abstractGalactic winds are observed in many spiral galaxies with sizes from dwarfs up to the Milky Way, and they sometimes carry a mass in excess of that of newly formed stars by up to a factor of ten. Multiple driving processes of such winds have been proposed, including thermal pressure due to supernova-heating, UV radiation pressure on dust grains, or cosmic ray (CR) pressure. We here study wind formation due to CR physics using a numerical model that accounts for CR acceleration by supernovae, CR thermalization, and advective CR transport. In addition, we introduce a novel implementation of CR streaming relative to the rest frame of the gas. We find that CR streaming drives powerful and sustained winds in galaxies with virial masses M_200 < 10^{11} Msun. In dwarf galaxies (M_200 ~ 10^9 Msun) the winds reach a mass loading factor of ~5, expel ~60 per cent of the initial baryonic mass contained inside the halo's virial radius and suppress the star formation rate by a factor of ~5. In dwarfs, the winds are spherically symmetric while in larger galaxies the outflows transition to bi-conical morphologies that are aligned with the disc's angular momentum axis. We show that damping of Alfven waves excited by streaming CRs provides a means of heating the outflows to temperatures that scale with the square of the escape speed. In larger haloes (M_200 > 10^{11} Msun), CR streaming is able to drive fountain flows that excite turbulence. For halo masses M_200 > 10^{10} Msun, we predict an observable level of H-alpha and X-ray emission from the heated halo gas. We conclude that CR-driven winds should be crucial in suppressing and regulating the first epoch of galaxy formation, expelling a large fraction of baryons, and - by extension - aid in shaping the faint end of the galaxy luminosity function. They should then also be responsible for much of the metal enrichment of the intergalactic medium.en
dc.language.isoenen
dc.publisherWiley Interscience for the RASen
dc.relation.urihttp://adsabs.harvard.edu/doi/10.1111/j.1365-2966.2012.21045.xen
dc.relation.urihttp://arxiv.org/abs/1203.1038en
dc.relation.urihttp://dx.doi.org/10.1111/j.1365-2966.2012.21045.xen
dc.rights2012 The authors & the Royal Astronomical Society.en
dc.subjectgalaxies: dwarfen
dc.subjectgalaxies: evolutionen
dc.subjectgalaxies: formationen
dc.subjectintergalactic mediumen
dc.subjectgalaxies: starbursten
dc.titleGalactic winds driven by cosmic ray streamingen
dc.typeArticleen
Appears in Collections:Research Papers (A&A)

Files in This Item:
File Description SizeFormat 
2012_MNRAS_423_2374.pdf
  Restricted Access		Restricted Access9.33 MBAdobe PDFView/Open Request a copy
Show simple item record


Items in RRI Digital Repository are protected by copyright, with all rights reserved, unless otherwise indicated.