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dc.contributor.authorKONG, Shuo
hal.structure.identifierINAF - Osservatorio Astrofisico di Arcetri [OAA]
dc.contributor.authorCASELLI, Paola
hal.structure.identifierLaboratoire Hubert Curien [LHC]
dc.contributor.authorTAN, Jonathan C.
hal.structure.identifierAMOR 2015
dc.contributor.authorWAKELAM, Valentine
dc.contributor.authorSIPILÄ, Olli
dc.date.created2013-12-03
dc.date.issued2015-05
dc.identifier.issn0004-637X
dc.description.abstractEnThe deuterium fraction, [N2D+]/[N2H+], may provide information about the ages of dense, cold gas structures, which are important for comparing dynamical models of cloud core formation and evolution. Here we introduce a complete chemical network with species containing up to three atoms, with the exception of the oxygen chemistry, where reactions involving H3O+ and its deuterated forms have been added, significantly improving the consistency with comprehensive chemical networks. Deuterium chemistry and spin states of H2 and H3+ isotopologues are included in this primarily gas-phase chemical model. We investigate the dependence of deuterium chemistry on these model parameters: density ({{n}H}), temperature, cosmic ray ionization rate, and gas-phase depletion factor of heavy elements ({{f}D}). We also explore the effects of time-dependent freeze-out of gas-phase species and the dynamical evolution of density at various rates relative to free-fall collapse. For a broad range of model parameters, the timescales to reach large values of Dfrac{{N2}{{H}+}}≳ 0.1, observed in some low- and high-mass starless cores, are relatively long compared to the local free-fall timescale. These conclusions are unaffected by introducing time-dependent freeze-out and considering models with evolving density, unless the initial {{f}D} ≳ 10. For fiducial model parameters, achieving Dfrac{{N2}{{H}+}}≳ 0.1 requires collapse to be proceeding at rates at least several times slower than that of free-fall collapse, perhaps indicating a dynamically important role for magnetic fields in supporting starless cores and thus the regulation of star formation.
dc.language.isoen
dc.publisherAmerican Astronomical Society
dc.title.enTHE DEUTERIUM FRACTIONATION TIMESCALE IN DENSE CLOUD CORES: A PARAMETER SPACE EXPLORATION
dc.typeArticle de revue
dc.identifier.doi10.1088/0004-637X/804/2/98
dc.subject.halPhysique [physics]/Astrophysique [astro-ph]/Astrophysique stellaire et solaire [astro-ph.SR]
dc.identifier.arxiv1312.0971
bordeaux.journalThe Astrophysical Journal
bordeaux.pageid. 98
bordeaux.volume804
bordeaux.issue2
bordeaux.peerReviewedoui
hal.identifierhal-00914300
hal.version1
hal.popularnon
hal.audienceNon spécifiée
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00914300v1
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