J/A+A/636/A8ivo://CDS.VizieR/J/A+A/636/A8doi:10.26093/cds/vizier.36360008CDSYildiz M.K.Peletier R.F.Duc P.-A.Serra P.2020-08-21T08:44:50Z2020-04-07T08:02:30ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiesphotometryObservations of neutral hydrogen (HI) and molecular gas show that 50% of all nearby early-type galaxies (ETGs) contain some cold gas. Molecular gas is always found in small gas discs in the central region of the galaxy, while neutral hydrogen is often distributed in a low-column density disc or ring typically extending well beyond the stellar body. Dust is frequently found in ETGs as well. The goal of our study is to understand the link between dust and cold gas in nearby ETGs as a function of HI content. We analyse deep optical g-r images obtained with the MegaCam camera at the Canada-France-Hawaii Telescope for a sample of 21 HI-rich and 41 HI-poor ETGs. We find that all HI- rich galaxies contain dust seen as absorption. Moreover, in 57 percent of these HI-rich galaxies, the dust is distributed in a large-scale spiral pattern. Although the dust detection rate is relatively high in the HI-poor galaxies (59 percent), most of these systems exhibit simpler dust morphologies without any evidence of spiral structures. We find that the HI-rich galaxies possess more complex dust morphology extending to almost two times larger radii than HI-poor objects. We measured the dust content of the galaxies from the optical colour excess and find that HI-rich galaxies contain six times more dust (in mass) than HI-poor ones. In order to maintain the dust structures in the galaxies, continuous gas accretion is needed, and the substantial HI gas reservoirs in the outer regions of ETGs can satisfy this need for a long time. We find that there is a good correspondence between the observed masses of the gas and dust, and it is also clear that dust is present in regions further than 3 Reff. Our findings indicate an essential relation between the presence of cold gas and dust in ETGs and offer a way to study the interstellar medium in more detail than what is possible with. HI observations.2020A&A...636A...8Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/636/A8CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/636/A8https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/636/A8http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/636/A8https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/636/A8https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/636/A8http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/636/A8GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/636/A8/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/636/A8/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/636/A8/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/636/A8/list?GETtext/xml+votable180.050000true26.0606328.705880.0055555555555555566/664 2145 4567 4807 4829 4869 4989 5021 5125 5134 5182 5196 5198 5429 5474 5773 5975 5999 6012 6087 6090 6093 6097 6099 6103 7214 7287 7355 7374 9186 10454 10501 10551 10714 10720 11026 11246 11435 11443 11791 11824 13401 15204 27595 27604 27755 28220 28264 28311 28362 28495 28538 28653 32168 32539https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/636/A8?format=asciidefaultJ/A+A/636/A8/listList of fits imagesSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension of center (J2000)degpos.eq.ra;meta.mainDEJ2000Declination of center (J2000)degpos.eq.dec;meta.mainNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintObs.dateObservation datetime.epoch;obsnullablesizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar