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hal.structure.identifierInstituto de Astrofísica de Andalucía [IAA]
dc.contributor.authorLISENFELD, Ute
hal.structure.identifierLaboratoire d'Astrophysique de Bordeaux [Pessac] [LAB]
dc.contributor.authorBRAINE, J.
hal.structure.identifierAstrophysique Interprétation Modélisation [AIM (UMR_7158 / UMR_E_9005 / UM_112)]
dc.contributor.authorDUC, Pierre-Alain
hal.structure.identifierInstituto Nacional de Astrofísica Óptica y Electrónica [INAOE]
dc.contributor.authorBRINKS, E.
hal.structure.identifierDepartment of Astronomy, Cornell University
hal.structure.identifierLaboratoire d'Etude du Rayonnement et de la Matière en Astrophysique [LERMA]
dc.contributor.authorCHARMANDARIS, Vassilis
hal.structure.identifierInstituto de Astrofísica de Andalucía [IAA]
dc.contributor.authorLÉON, Sylvie
dc.date.issued2004
dc.identifier.issn0004-6361
dc.description.abstractEnWe have mapped with the IRAM interferometer at Plateau de Bure (PdBI) the <SUP>12</SUP>CO emission towards intergalactic star forming regions located in the tidal tail stemming from NGC 7319, in the Stephan's Quintet compact group of galaxies. The <SUP>13</SUP>CO emission of the same region was observed with the IRAM 30 m telescope and optical spectroscopy of several HII regions in the area were obtained with the Calar Alto 3.5 m telescope.We recovered with the interferometer about 50% of the <SUP>12</SUP>CO(1-0) total emission that had been earlier measured with single dish observations (Lisenfeld 2002, A&A, 394, 823), indicating that about half of the molecular gas is distributed on spatial scales larger than about 10-15 arcsec (corresponding to 4-6 kpc) to which PdBI is not sensitive. We find two main areas of CO emission: (i) an elongated region towards the area known as SQ B where a Tidal Dwarf Galaxy could currently be forming and (ii) a barely resolved area at the tip of the optical tidal arm. Both regions follow dust lanes visible on HST images and their CO peak coincides spatially exactly with the maximum of the Halpha line emission. In SQ B, there is furthermore very good kinematical agreement between the CO, Halpha and HI components. We conclude from these coincidences that the gaseous matter found in quantities in the area is physically associated to the optical tidal tail and thus that the intergalactic atomic hydrogen there was expelled from NGC 7319. Its origin had previously been much debated. Furthermore, the relatively high oxygen abundances (about solar) estimated from the optical spectra of the HII regions imply that the gas feeding the star formation originated from the inner regions of the parent galaxy. In SQ B, we derive from different tracers a star formation rate, corrected for dust extinction - which is important in the area - of 0.5 M<SUB>&sun;</SUB>/yr, i.e. one of the highest values so far measured outside galaxies. The inferred molecular gas consumption time of 0.5 Gyr lies in the range of values found for spiral and starburst galaxies. On the other hand, the ratio of <SUP>12</SUP>CO/<SUP>13</SUP>CO > 25 is much higher than the values found in disks of spiral galaxies. A relatively low opacity for the <SUP>12</SUP>CO gas is the most likely reason.
dc.language.isoen
dc.publisherEDP Sciences
dc.title.enMolecular and ionized gas in the tidal tail in Stephan's Quintet
dc.typeArticle de revue
dc.identifier.doi10.1051/0004-6361:20041330
dc.subject.halPhysique [physics]/Astrophysique [astro-ph]
dc.subject.halPlanète et Univers [physics]
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.page471-479
bordeaux.volume426
bordeaux.peerReviewedoui
hal.identifierhal-03784863
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-03784863v1
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