J/A+A/618/A35ivo://CDS.VizieR/J/A+A/618/A35doi:10.26093/cds/vizier.36180035CDSGoicoechea J.R.Pety J.Chapillon E.Cernicharo J.Gerin M.,Herrera C.Requena-Torres M.A.Santa-Maria M.G.2018-12-20T14:40:28Z2018-10-10T06:15:36ZCDS support team

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

cds-question@unistra.frinterstellar-mediummolecular-cloudsinterferometryWe present 1"-resolution ALMA observations of the circumnuclear disk (CND) and the environment around SgrA*. The images unveil the presence of small spatial scale CO (J=3-2) molecular "cloudlets" within the central pc of the Milky Way, moving at high speeds, up to 300km/s along the line-of-sight. The CO-emitting structures show intricate morphologies: extended and filamentary at high negative-velocities (v_LSR_<-150km/s), more localized and clumpy at extreme positive-velocities (v_LSR_>+200km/s). Based on the pencil-beam CO absorption spectrum toward SgrA* synchrotron emission, we also present evidence for a diffuse gas component producing absorption features at more extreme negative-velocities (v_LSR_<-200km/s). The CND shows a clumpy spatial distribution. Its motion requires a bundle of non-uniformly rotating streams of slightly different inclinations. The inferred gas density peaks are lower than the local Roche limit. This supports that CND molecular cores are transient. We apply the two standard orbit models, spirals vs. ellipses, invoked to explain the kinematics of the ionized gas streamers around SgrA*. The location and velocities of the CO cloudlets are inconsistent with the spiral model, and only two of them are consistent with the Keplerian ellipse model. Most cloudlets, however, show similar velocities that are incompatible with the motions of the ionized streamers or with gas bounded to the central gravity. We speculate that they are leftovers of more massive, tidally disrupted, clouds that fall into the cavity, or that they originate from instabilities in the inner rim of the CND and infall from there. Molecular cloudlets, all together with a mass of several 10M_{sun}_, exist around SgrA*. Most of them must be short-lived: photoevaporated by the intense stellar radiation field, blown away by winds from massive stars, or disrupted by strong gravitational shears.2018A&A...618A..35Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/618/A35CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/428/2731 : SgrA* emission at 7mm (Beaklini+, 2013)J/ApJ/820/90 : 4yr 1.3mm VLBI observations of SgrA* with EHT (Fish+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/618/A35https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/618/A35http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/618/A35https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/618/A35https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/618/A35http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/618/A35GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/618/A35/list (List of fits images)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/618/A35/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/618/A35/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/618/A35/list?GETtext/xml+votable180.050000true266.41699-29.01020.005555555555555556Associated datahttps://cdsarc.cds.unistra.fr/assocdata/?obs_collection=J/A+A/618/A356/28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/618/A35?format=asciidefaultJ/A+A/618/A35/listList of fits imagesrecnoRecord 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.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitsAssocDataAssociated Data web pagemeta.ref.urlchar