Afficher la notice abrégée

Colliding molecular clouds in head-on galaxy collisions

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.authorBRAINE, J.
dc.contributor.authorLISENFELD, U.
hal.structure.identifierDépartement d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée [DAPNIA]
dc.contributor.authorDUC, P.A.
dc.contributor.authorBRINKS, E.
hal.structure.identifierLaboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA]
dc.contributor.authorCHARMANDARIS, V.
dc.contributor.authorLEON, S.
dc.date.created2004
dc.date.issued2004
dc.identifier.issn0004-6361
dc.description.abstractEnWe present further observations of molecular gas in head-on collisions of spiral galaxies, this time of the CO(J=1-0) and CO(J=2-1) lines in the UGC 813 -- UGC 816 system. UGC 813/6 are only the second known example of head-on spiral-spiral collisions, the first example being the UGC 12914/5 pair. Strong CO emission is present in the bridge between UGC 813 and 816, unassociated with stellar emission, just as in UGC 12914/5. The CO emission from the UGC 813/6 bridge, not counting the emission from the galaxies themselves, is at least that of the entire Milky Way. Collisions of gas-rich spirals are really collisions between the interstellar media (ISMs) of the galaxies. We show that collisions between molecular clouds bring H2 into the bridge region. Although the dense clouds are ionized by the collisions, they cool and recombine very quickly and become molecular again even before the galactic disks separate. Because the clouds acquire an intermediate velocity post-collision, they are left in the bridge between the separating galaxies. The star formation efficiency appears low in the molecular clouds in the bridges. We speculate that the pre-stellar cores in the molecular clouds may expand during the cloud collisions, thus retarding future star formation. Because the ISM-ISM collisions discussed here require a very small impact parameter, they are rare among field spirals. In clusters, however, these collisions should be an important means of ejecting enriched gas from the inner parts of spirals.
dc.language.isoen
dc.publisherEDP Sciences
dc.title.enColliding molecular clouds in head-on galaxy collisions
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/0402148
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.page419-428
bordeaux.volume418
bordeaux.peerReviewedoui
hal.identifierhal-00012315
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00012315v1
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=418&rft.spage=419-428&rft.epage=419-428&rft.eissn=0004-6361&rft.issn=0004-6361&rft.au=BRAINE,%20J.&LISENFELD,%20U.&DUC,%20P.A.&BRINKS,%20E.&CHARMANDARIS,%20V.&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