J/A+A/589/A28ivo://CDS.VizieR/J/A+A/589/A28doi:10.26093/cds/vizier.35890028CDSRequena-Torres M.A.Israel F.P.Okada Y.Guesten R.Stutzki J.,Risacher C.Simon R.Zinnecker H.2016-04-08T08:02:21Z2016-04-08T07:28:49ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsinterstellar-mediumspectroscopyThis paper presents [CII], [CI] and CO emission line maps of the star-forming regions N66, N25+N26, and N88 in the metal-poor Local Group dwarf galaxy SMC. The spatial and velocity structure of the large HII region N66 reveals an expanding ring of shocked molecular gas centered on the exciting star cluster NGC346, whereas a more distant dense molecular cloud is being eroded by UV radiation from the same cluster. In the N25+N26 and N88 maps, diffuse [CII] emission at a relatively low surface brightness extends well beyond the compact boundaries of the bright emission associated with the HII regions. In all regions, the distribution of this bright [CII] emission and the less prominent [CI] emission closely follows the outline of the CO complexes, but the intensity of the [CII] and [CI] emission is generally anticorrelated, which can be understood by the action of photodissociation and photoionization processes. Notwithstanding the overall similarity of CO and [CII] maps, the intensity ratio of these lines varies significantly, mostly due to changes in CO brightness. [CII] emission line profiles are up to 50% wider in velocity than corresponding CO profiles. A radiative transfer analysis shows that the [CII] line is the dominant tracer of (CO-dark) molecular hydrogen in the SMC. CO emission traces only a minor fraction of the total amount of gas. The similarity of the spatial distribution and line profile shape, and the dominance of molecular gas associated with CII rather than CO emission imply that in the low-metallicity environment of the SMC the small amount of dense molecular gas traced by CO is embedded in the much more extended molecular gas traced only by [CII] emission. The contribution from neutral atomic and ionized hydrogen zones is negligible in the star-forming regions observed2016A&A...589A..28Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/589/A28CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/589/A28https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/589/A28http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/589/A28https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/589/A28https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/589/A28http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/589/A28GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/589/A28/list (List of fits files)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/589/A28/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/589/A28/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/589/A28/list?GETtext/xml+votable180.050000true12.03308-73.24680.0055555555555555566/33295 33299 33328https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/589/A28?format=asciidefaultJ/A+A/589/A28/listList of fits filesFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharrecnoRecord 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.numberintNz? Number of pixels along Z-axismeta.numberintnullablebAngleGLS? Lower value of GLS angle intervaldegpos.posAngfloatnullableBAngleGLS? Upper value of GLS angle intervaldegpos.posAngfloatnullabledAngleGLS? GLS angle resolutiondegpos.posAngdoublenullablebVRADLower value of VRAD intervalkm/sphys.veloc;pos.heliocentricdoubleBVRADUpper value of VRAD intervalkm/sphys.veloc;pos.heliocentricdoubledVRADVRAD interval resolutionkm/spos.angResolutiondoublesizeSize of FITS fileKibytephys.size;meta.fitsintTitleTitle of the FITS filemeta.title;meta.fits