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hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
dc.contributor.authorWAKELAM, V.
hal.structure.identifierInstitut de recherche en astrophysique et planétologie [IRAP]
dc.contributor.authorCOUTENS, A.
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
dc.contributor.authorGRATIER, P.
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
dc.contributor.authorVIDAL, T. H. G.
dc.contributor.authorVAYTET, N.
dc.date.issued2022
dc.identifier.issn0004-6361
dc.description.abstractEnContext. The observational counterparts of theoretically predicted first hydrostatic cores (FHSC) have been searched for in the interstellar medium for nearly two decades now. Distinguishing them from other types of more evolved but still embedded objects remains a challenge because these objects have a short lifetime, are small, and embedded in a dense cocoon. One possible lead to finding them is the characterization of the outflows that are launched by these objects, which are assumed to have a low velocity and be small extent. <BR /> Aims: We observed the L1451-mm FHSC candidate with the NOEMA interferometer (and complementary IRAM 30m data) in order to study the emission of several molecules. <BR /> Methods: Molecular lines were reduced and analyzed with the GILDAS package network, the CASSIS software, and some python packages. A nonlocal thermodynamic equilibrium analysis of the CH<SUB>3</SUB>OH detected lines was performed to retrieve the physical conditions of the emitting region around the central source, together with the CH<SUB>3</SUB>OH, SiO, CS, and H<SUB>2</SUB>CO column densities. <BR /> Results: Of the targeted molecules, we detected lines of c-C<SUB>3</SUB>H<SUB>2</SUB>, CH<SUB>3</SUB>OH, CS, C<SUP>34</SUP>S, SO, DCN, DCO+, H<SUB>2</SUB>CO, HC<SUB>3</SUB>N, HDCO, and SiO. One of the methanol lines appears to be a maser line. The detection of this class I maser and the SiO line in L1451-mm support the presence of a low-velocity and compact outflow. The excitation conditions of the thermal lines of methanol are also compatible with shocks (H<SUB>2</SUB> density of ~3 × 10<SUP>6</SUP> cm<SUP>−3</SUP> and a temperature higher than 40 K). <BR /> Conclusions: Although these low-velocity outflows are theoretically predicted by some models of FHSC, these models also predict the shock temperature to be below 20 K, that is, not evaporating methanol. In addition, the predicted velocities would not erode the grains and release silicon in the gas phase. We therefore conclude that these new observations favor the hypothesis that L1451-mm would be at a very early protostellar stage, launching an outflow nearly on the plane of the sky with a higher velocity than is observed. <P />The reduced datacubes used for this work are also available at the CDS via anonymous ftp to ftp://cdsarc.u-strasbg.fr (<A href="http://130.79.128.5">130.79.128.5</A>) or via <A href="http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/666/A191">http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/666/A191</A>
dc.language.isoen
dc.publisherEDP Sciences
dc.rights.urihttp://creativecommons.org/licenses/by/
dc.subject.enastrochemistry
dc.subject.enstars: protostars
dc.subject.enISM: molecules
dc.subject.enISM: individual objects: L1451-mm
dc.subject.enstars: low-mass
dc.subject.enAstrophysics - Astrophysics of Galaxies
dc.title.enConfirmation of the outflow in L1451-mm: SiO line and CH<SUB>3</SUB>OH maser detections
dc.typeArticle de revue
dc.identifier.doi10.1051/0004-6361/202243459
dc.subject.halPlanète et Univers [physics]
dc.subject.halPlanète et Univers [physics]/Astrophysique [astro-ph]
dc.identifier.arxiv2208.13606
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.volume666
bordeaux.peerReviewedoui
hal.identifierinsu-03863529
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//insu-03863529v1
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