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dc.contributor.authorForgan, D. H.
dc.contributor.authorBonnell, I. A.
dc.date.accessioned2018-10-25T15:30:08Z
dc.date.available2018-10-25T15:30:08Z
dc.date.issued2018-12-21
dc.identifier256332258
dc.identifier07386a9d-1497-4890-a162-b19d81fb9732
dc.identifier85054717529
dc.identifier000454575100022
dc.identifier.citationForgan , D H & Bonnell , I A 2018 , ' Clumpy shocks as the driver of velocity dispersion in molecular clouds : the effects of self-gravity and magnetic fields ' , Monthly Notices of the Royal Astronomical Society , vol. 481 , no. 4 , pp. 4532-4541 . https://doi.org/10.1093/mnras/sty2580en
dc.identifier.issn0035-8711
dc.identifier.urihttps://hdl.handle.net/10023/16325
dc.descriptionDHF and IAB gratefully acknowledge support from the ECOGAL project, grant agreement 291227, funded by the European Research Council under ERC-2011-ADG.en
dc.description.abstractWe revisit an alternate explanation for the turbulent nature of molecular clouds - namely, that velocity dispersions matching classical predictions of driven turbulence can be generated by the passage of clumpy material through a shock. While previous work suggested this mechanism can reproduce the observed Larson relation between velocity dispersion and size scale (σ ∝ LΓ with Γ ≈ 0.5), the effects of self-gravity and magnetic fields were not considered. We run a series of smoothed particle magnetohydrodynamics experiments, passing clumpy gas through a shock in the presence of a combination of self-gravity and magnetic fields.We find power-law relations between σ and L throughout, with indices ranging from Γ = 0.3-1.2. These results are relatively insensitive to the strength and geometry of magnetic fields, provided that the shock is relatively strong. Γ is strongly sensitive to the angle between the gas' bulk velocity, and the shock front and the shock strength (compared to the gravitational boundness of the pre-shock gas). If the origin of the σ-L relation is in clumpy shocks, deviations from the standard Larson relation constrain the strength and behaviour of shocks in spiral galaxies.
dc.format.extent10
dc.format.extent2549313
dc.language.isoeng
dc.relation.ispartofMonthly Notices of the Royal Astronomical Societyen
dc.subjectHydrodynamicsen
dc.subjectISM: cloudsen
dc.subjectISM: kinematics and dynamicen
dc.subjectISM: structureen
dc.subjectMethods: numericalen
dc.subjectMHDen
dc.subjectQB Astronomyen
dc.subjectAstronomy and Astrophysicsen
dc.subjectSpace and Planetary Scienceen
dc.subjectNDASen
dc.subject.lccQBen
dc.titleClumpy shocks as the driver of velocity dispersion in molecular clouds : the effects of self-gravity and magnetic fieldsen
dc.typeJournal articleen
dc.contributor.sponsorEuropean Research Councilen
dc.contributor.institutionUniversity of St Andrews. School of Physics and Astronomyen
dc.contributor.institutionUniversity of St Andrews. St Andrews Centre for Exoplanet Scienceen
dc.identifier.doi10.1093/mnras/sty2580
dc.description.statusPeer revieweden
dc.identifier.grantnumberen


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