Show simple item record

hal.structure.identifierCentre d'étude spatiale des rayonnements [CESR]
dc.contributor.authorMARET, Sébastien
hal.structure.identifierLaboratoire d'Astrophysique de Grenoble [LAOG]
dc.contributor.authorCECCARELLI, C.
hal.structure.identifierCentre d'étude spatiale des rayonnements [CESR]
dc.contributor.authorCAUX, Emmanuel
hal.structure.identifierSRON Netherlands Institute for Space Research [SRON]
dc.contributor.authorTIELENS, Alexander
hal.structure.identifierLeiden Observatory [Leiden]
dc.contributor.authorJORGENSEN, Jes
hal.structure.identifierLeiden Observatory [Leiden]
dc.contributor.authorVAN DISHOECK, Ewine
hal.structure.identifierEuropean Southern Observatory [ESO]
dc.contributor.authorBACMANN, A.
hal.structure.identifierUniversité Sciences et Technologies - Bordeaux 1 [UB]
hal.structure.identifierLaboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux [L3AB]
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
hal.structure.identifierObservatoire aquitain des sciences de l'univers [OASU]
dc.contributor.authorCASTETS, Alain
hal.structure.identifierLaboratoire d'Astrophysique de Grenoble [LAOG]
dc.contributor.authorLEFLOCH, Bertrand
hal.structure.identifierInstitut de Astronomia [Institut de Astronomia]
dc.contributor.authorLOINARD, Laurent
hal.structure.identifierCentre d'étude spatiale des rayonnements [CESR]
dc.contributor.authorPARISE, Bérengère
hal.structure.identifierLeiden Observatory [Leiden]
dc.contributor.authorSCHOEIER, Fredrik
dc.date.issued2004
dc.identifier.issn0004-6361
dc.description.abstractEnWe present a survey of the formaldehyde emission in a sample of eight Class 0 protostars obtained with the IRAM and JCMT telescopes. The data have been analyzed with three different methods with increasing level of sophistication. We first analyze the observed emission in the LTE approximation, and derive rotational temperatures between 11 and 40 K, and column densities between 1 and 20 x 10^13 cm^-2. Second, we use a LVG code and derive larger kinetic temperatures, between 30 and 90 K, consistent with subthermally populated levels and densities from 1 to 6 x 10^5 cm^-3. The column densities from the LVG modeling are within a factor of 10 with respect to those derived in the LTE approximation. Finally, we analyze the observations based upon detailed models for the envelopes surrounding the protostars, using temperature and density profiles previously derived from continuum observations. We approximate the formaldehyde abundance across the envelope with a jump function, the jump occurring when the dust temperature reaches 100 K, the evaporation temperature of the grain mantles. The observed formaldehyde emission is well reproduced only if there is a jump, more than two orders of magnitude, in four sources. In the remaining four sources the data are consistent with a formaldehyde abundance jump, but the evidence is more marginal (~2 sigma). The inferred inner H2CO abundance varies between 1 x 10^-8 and 6 x 10^-6. We discuss the implications of these jumps for our understanding of the origin and evolution of ices in low mass star forming regions. Finally, we give predictions for the submillimeter H2CO lines, which are particularly sensitive to the abundance jumps.
dc.language.isoen
dc.publisherEDP Sciences
dc.subject.enISM: abundances
dc.subject.enISM: molecules
dc.subject.enStars: formation
dc.subject.enISM: individual: NGC1333-IRAS4A
dc.subject.enNGC1333-IRAS4B
dc.subject.enNGC1333-IRAS2
dc.subject.enL1448-MM
dc.subject.enL1448-N
dc.subject.enL1157-MM
dc.subject.enVLA1623
dc.subject.enL1527
dc.subject.enIRAS16293-2422
dc.title.enThe H2CO abundance in the inner warm regions of low mass protostellar envelopes
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]
dc.identifier.arxivastro-ph/0310536
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.page577-594
bordeaux.volume416
bordeaux.peerReviewedoui
hal.identifierhal-00000759
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00000759v1
bordeaux.COinSctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Astronomy%20and%20Astrophysics%20-%20A&A&rft.date=2004&rft.volume=416&rft.spage=577-594&rft.epage=577-594&rft.eissn=0004-6361&rft.issn=0004-6361&rft.au=MARET,%20S%C3%A9bastien&CECCARELLI,%20C.&CAUX,%20Emmanuel&TIELENS,%20Alexander&JORGENSEN,%20Jes&rft.genre=article


Files in this item

FilesSizeFormatView

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record