Afficher la notice abrégée

Survey of ortho-H2D+(1_{1,0}-1_{1,1}) in dense cloud cores

hal.structure.identifierINAF - Osservatorio Astrofisico di Arcetri [OAA]
dc.contributor.authorCASELLI, Paola
hal.structure.identifierCentre d'étude spatiale des rayonnements [CESR]
dc.contributor.authorVASTEL, Charlotte
hal.structure.identifierLaboratoire d'Astrophysique de Grenoble [LAOG]
dc.contributor.authorCECCARELLI, Cecilia
hal.structure.identifierMax-Planck-Institut für Radioastronomie [MPIFR]
dc.contributor.authorVAN DER TAK, Floris
dc.contributor.authorCRAPSI, Antonio
hal.structure.identifierLaboratoire d'Astrophysique de Grenoble [LAOG]
hal.structure.identifierObservatoire aquitain des sciences de l'univers [OASU]
hal.structure.identifierLaboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
dc.contributor.authorBACMANN, A.
dc.date.created2008
dc.date.issued2008
dc.identifier.issn0004-6361
dc.description.abstractEnWe present a survey of the ortho-H2D+(1_{1,0}-1_{1,1}) line toward a sample of 10 starless cores and 6 protostellar cores, carried out at the Caltech Submillimeter Observatory. The high diagnostic power of this line is revealed for the study of the chemistry, and the evolutionary and dynamical status of low-mass dense cores. The line is detected in 7 starless cores and in 4 protostellar cores. N(ortho-H2D+) ranges between 2 and 40x10^{12} cm^{-2} in starless cores and between 2 and 9x10^{12} cm^{-2} in protostellar cores. The brightest lines are detected toward the densest and most centrally concentrated starless cores, where the CO depletion factor and the deuterium fractionation are also largest. The large scatter observed in plots of N(ortho-H2D+) vs. the observed deuterium fractionation and vs. the CO depletion factor is likely to be due to variations in the ortho-to-para (o/p) ratio of H2D+ from >0.5 for T_{kin} < 10 K gas in pre-stellar cores to ~0.03 (consistent with T_{kin} ~15 K for protostellar cores). The two Ophiuchus cores in our sample also require a relatively low o/p ratio (~0.3). Other parameters, including the cosmic-ray ionization rate, the CO depletion factor (or, more in general, the depletion factor of neutral species), the volume density, the fraction of dust grains and PAHs also largely affect the ortho-H2D+ abundance. The most deuterated and H2D+-rich objects (L429, L1544, L694-2 and L183) are reproduced by chemical models of centrally concentrated (central densties ~10^{6} cm^{-3}) cores with chemical ages between 10^4 and 10^6 yr. Upper limits of the para-H3O+ (1_1- -2_1+) and para-D2H+ (1_{1,0}-1_{0,1}) lines are also given. (Abridged)
dc.language.isoen
dc.publisherEDP Sciences
dc.title.enSurvey of ortho-H2D+(1_{1,0}-1_{1,1}) in dense cloud cores
dc.typeArticle de revue
dc.subject.halPhysique [physics]/Astrophysique [astro-ph]/Cosmologie et astrophysique extra-galactique [astro-ph.CO]
dc.subject.halPlanète et Univers [physics]/Astrophysique [astro-ph]/Astrophysique stellaire et solaire [astro-ph.SR]
dc.subject.halPhysique [physics]/Astrophysique [astro-ph]/Astrophysique stellaire et solaire [astro-ph.SR]
dc.identifier.arxiv0809.2803
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.page703-718
bordeaux.volume492
bordeaux.issue3
bordeaux.peerReviewedoui
hal.identifierhal-00429286
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00429286v1
bordeaux.COinSctx_ver=Z39.88-2004&amp;rft_val_fmt=info:ofi/fmt:kev:mtx:journal&amp;rft.jtitle=Astronomy%20and%20Astrophysics%20-%20A&A&amp;rft.date=2008&amp;rft.volume=492&amp;rft.issue=3&amp;rft.spage=703-718&amp;rft.epage=703-718&amp;rft.eissn=0004-6361&amp;rft.issn=0004-6361&amp;rft.au=CASELLI,%20Paola&amp;VASTEL,%20Charlotte&amp;CECCARELLI,%20Cecilia&amp;VAN%20DER%20TAK,%20Floris&amp;CRAPSI,%20Antonio&amp;rft.genre=article


Fichier(s) constituant ce document

FichiersTailleFormatVue

Il n'y a pas de fichiers associés à ce document.

Ce document figure dans la(les) collection(s) suivante(s)

Afficher la notice abrégée