J/A+A/684/A142ivo://CDS.VizieR/J/A+A/684/A142doi:10.26093/cds/vizier.36840142CDSZhang X.Qiu K.Zhang Q.Cao Y.Cheng Y.Liu J.Wang Y.Lu X.Pan X.2024-11-07T20:02:23Z2024-04-18T18:34:33ZCDS support team

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

cds-question@unistra.frmolecular-cloudsgalaxy-kinematicsradio-astronomyThe physical properties, evolution, and fragmentation of massive dense cores (MDCs, ~0.1pc) are fundamental to the understanding of high-mass star formation. We aim at characterizing the temperature, velocity dispersion, and fragmentation of the MDCs in the Cygnus X giant molecular cloud and to investigate their stability and dynamics. We present the Karl G. Jansky Very Large Array (VLA) observations of the NH_3_ (J, K) = (1,1) and (2,2) inversion lines towards 35 MDCs in Cygnus X, from which the temperature and velocity dispersion are calculated. We extract 202 fragments (~0.02pc) from the NH_3_ (1,1) moment-0 maps with the GAUSSCLUMPS algorithm. The stability of the MDCs and their NH_3_ fragments is analyzed through evaluating the corresponding kinetic, gravitational potential, and magnetic energies and the virial parameters. The MDCs in Cygnus X have a typical mean kinetic temperature TK of ~20K. Virial analysis shows that many MDCs are at sub-virialized states, indicating that the kinetic energy is insufficient to support these MDCs against their gravity. The calculated non-thermal velocity dispersions of most MDCs are at transonic to mildly supersonic levels, and the bulk motions only have a minor contribution to the velocity dispersion. As for the NH_3_ fragments, with TK~19K, their non-thermal velocity dispersions are mostly trans- to sub-sonic. Unless there is a strong magnetic field, most NH_3_ fragments are probably not at virialized states. We also find that most of the NH_3_ fragments are dynamically quiescent while only a few are active due to star formation activity.2024A&A...684A.142Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/684/A142CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/241/551 : Radio continuum in Cygnus X region (Wendker+ 1991)J/A+A/375/539 : JHK photometry of compact HII regions in Cyg XJ/A+A/407/1039 : X-ray power spectra of Cygnus X-1 (Pottschmidt+, 2003)J/A+A/452/975 : Temporal variability of Cygnus X-1 (Axelsson+, 2006)J/A+A/476/1243 : Millimeter continuum mapping of Cygnus X (Motte+, 2007)J/A+A/527/A135 : Gas dynamics in Massive Dense Cores in Cygnus-XJ/ApJ/720/679 : Optical spectroscopy in Cygnus X region (Beerer+, 2010)J/ApJ/727/114 : BLAST 2005: a 10deg^2^ survey in Cygnus X (Roy+, 2011)J/A+A/570/A1 : Cygnus-X CO and SiO outflows datacubesJ/AJ/148/11 : Infrared photometry in Cygnus-X (Kryukova+, 2014)J/MNRAS/458/3027 : Young and embedded clusters in Cygnus-X (Maia+, 2016)J/ApJ/883/156 : Nobeyama 45m Cygnus-X CO. II. C180 clumps (Takekoshi+, 2019)J/A+A/653/A108 : Globules and pillars in Cygnus X (Schneider+, 2021)J/A+A/664/A88 : LOFAR 148MHz Cygnus X region image (Emig+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/684/A142https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/684/A142http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/684/A142https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/684/A142https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/684/A142http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/684/A142GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/684/A142/tablef1 (Physical parameters of the ammonia fragments)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/684/A142/tablef1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/684/A142/tablef1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/684/A142/tablef1?GETtext/xml+votable180.050000true309.035341.66550.0055555555555555566/14621 14647 14665 14667 14670-14671 14682 14689 14692-14693 14696-14697 14704https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/684/A142?format=asciiRadiodefaultJ/A+A/684/A142/tablef1Physical parameters of the ammonia fragmentsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainMajMajor axisarcsecphys.angSizefloatMinMinor axisarcsecphys.angSize;srcfloatthetaPosition angledegpos.posAngfloatReffEffective radiuspcphys.size.radiusfloatRdecDeconvolved radiuspcphys.size.radiusfloatTkKinetic temperatureKphys.temperaturefloatsigmavVelocity dispersionkm/sphys.veloc.dispersionfloatvntNonthermal velocity dispersionkm/sphys.veloc.dispersionfloatvngNonthermal velocity dispersion excluding fitted bulk motionskm/sphys.veloc.dispersion;meta.modelledfloatMNTMach number of vntphys.veloc;arith.difffloatMngMach number of vngphys.veloc;arith.difffloatN(NH3)NH_3_ column density1e+15cm**-2phys.columnDensityfloat