THE DEUTERIUM FRACTIONATION TIMESCALE IN DENSE CLOUD CORES: A PARAMETER SPACE EXPLORATION
| dc.contributor.author | KONG, Shuo | |
| hal.structure.identifier | INAF - Osservatorio Astrofisico di Arcetri [OAA] | |
| dc.contributor.author | CASELLI, Paola | |
| hal.structure.identifier | Laboratoire Hubert Curien [LabHC] | |
| dc.contributor.author | TAN, Jonathan C. | |
| hal.structure.identifier | AMOR 2015 | |
| dc.contributor.author | WAKELAM, Valentine | |
| dc.contributor.author | SIPILÄ, Olli | |
| dc.date.created | 2013-12-03 | |
| dc.date.issued | 2015-05 | |
| dc.identifier.issn | 0004-637X | |
| dc.description.abstractEn | The 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.iso | en | |
| dc.publisher | American Astronomical Society | |
| dc.title.en | THE DEUTERIUM FRACTIONATION TIMESCALE IN DENSE CLOUD CORES: A PARAMETER SPACE EXPLORATION | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1088/0004-637X/804/2/98 | |
| dc.subject.hal | Physique [physics]/Astrophysique [astro-ph]/Astrophysique stellaire et solaire [astro-ph.SR] | |
| dc.identifier.arxiv | 1312.0971 | |
| bordeaux.journal | The Astrophysical Journal | |
| bordeaux.page | id. 98 | |
| bordeaux.volume | 804 | |
| bordeaux.issue | 2 | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-00914300 | |
| hal.version | 1 | |
| hal.popular | non | |
| hal.audience | Non spécifiée | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-00914300v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=The%20Astrophysical%20Journal&rft.date=2015-05&rft.volume=804&rft.issue=2&rft.spage=id.%2098&rft.epage=id.%2098&rft.eissn=0004-637X&rft.issn=0004-637X&rft.au=KONG,%20Shuo&CASELLI,%20Paola&TAN,%20Jonathan%20C.&WAKELAM,%20Valentine&SIPIL%C3%84,%20Olli&rft.genre=article |
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