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On the physical mechanisms governing the cloud lifecycle in the Central Molecular Zone of the Milky Way

Jeffreson, S M R; Kruijssen, J. M. Diederik; Krumholz, Mark; Longmore, Steven N

Description

We apply an analytic theory for environmentally dependent molecular cloud lifetimes to the Central Molecular Zone of the Milky Way. Within this theory, the cloud lifetime in the Galactic Centre is obtained by combining the time-scales for gravitational instability, galactic shear, epicyclic perturbations, and cloud–cloud collisions. We find that at galactocentric radii ∼45–120 pc, corresponding to the location of the ‘100-pc stream’, cloud evolution is primarily dominated by gravitational...[Show more]

dc.contributor.authorJeffreson, S M R
dc.contributor.authorKruijssen, J. M. Diederik
dc.contributor.authorKrumholz, Mark
dc.contributor.authorLongmore, Steven N
dc.date.accessioned2019-04-18T01:46:39Z
dc.date.available2019-04-18T01:46:39Z
dc.identifier.issn0035-8711
dc.identifier.urihttp://hdl.handle.net/1885/160451
dc.description.abstractWe apply an analytic theory for environmentally dependent molecular cloud lifetimes to the Central Molecular Zone of the Milky Way. Within this theory, the cloud lifetime in the Galactic Centre is obtained by combining the time-scales for gravitational instability, galactic shear, epicyclic perturbations, and cloud–cloud collisions. We find that at galactocentric radii ∼45–120 pc, corresponding to the location of the ‘100-pc stream’, cloud evolution is primarily dominated by gravitational collapse, with median cloud lifetimes between 1.4 and 3.9 Myr. At all other galactocentric radii, galactic shear dominates the cloud lifecycle, and we predict that molecular clouds are dispersed on time-scales between 3 and 9 Myr, without a significant degree of star formation. Along the outer edge of the 100-pc stream, between radii of 100 and 120 pc, the time-scales for epicyclic perturbations and gravitational free-fall are similar. This similarity of time-scales lends support to the hypothesis that, depending on the orbital geometry and timing of the orbital phase, cloud collapse and star formation in the 100-pc stream may be triggered by a tidal compression at pericentre. Based on the derived time-scales, this should happen in approximately 20 per cent of all accretion events on to the 100-pc stream.
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherBlackwell Publishing Ltd
dc.rights© 2018 The Author(s)
dc.sourceMonthly Notices of the Royal Astronomical Society
dc.titleOn the physical mechanisms governing the cloud lifecycle in the Central Molecular Zone of the Milky Way
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume478
dc.date.issued2018
local.identifier.absfor020104 - Galactic Astronomy
local.identifier.ariespublicationu4485658xPUB1774
local.publisher.urlhttp://www.oxfordjournals.org/
local.type.statusPublished Version
local.contributor.affiliationJeffreson, S M R, University of Heidelberg
local.contributor.affiliationKruijssen, J. M. Diederik, Zentrum fur Astronomie der Universit ¨ at Heidelberg
local.contributor.affiliationKrumholz, Mark, College of Science, ANU
local.contributor.affiliationLongmore, Steven N, Liverpool John Moores University
dc.relationhttp://purl.org/au-research/grants/arc/DP160100695
local.bibliographicCitation.issue3
local.bibliographicCitation.startpage3380
local.bibliographicCitation.lastpage3385
local.identifier.doi10.1093/mnras/sty1154
local.identifier.absseo970102 - Expanding Knowledge in the Physical Sciences
dc.date.updated2019-03-12T07:30:45Z
local.identifier.thomsonID000441282300037
dcterms.accessRightsOpen Access
dc.provenancehttp://sherpa.mimas.ac.uk/romeo/issn/0035-8711/..."author can archive publisher's version/PDF" from SHERPA/RoMEO site (as at 18/04/19).
CollectionsANU Research Publications

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