J/ApJ/897/89ivo://CDS.VizieR/J/ApJ/897/89doi:10.26093/cds/vizier.18970089CDSLi G.-X.Zhang C.-P.2022-03-10T07:27:45Z2021-10-13T13:58:09ZCDS support team

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

cds-question@unistra.frmilky-way-galaxygalactic-centerinterstellar-mediumstar-forming-regionsinfrared-photometryvisible-astronomyphotometryWe carry out a systematic study of the density structure of gas in the Central Molecular Zone (CMZ) in the Galactic center by extracting clumps from the APEX Telescope Large Area Survey of the Galaxy survey at 870{mu}m. We find that the clumps follow a scaling of m={rho}_0_r^3^, which corresponds to a characteristic density of n_H_2__=1.6x10^3^/cm^3^ ({rho}_0_=112M{sun}/pc^3^) with a variation of ~0.5dex, where we assumed a gas-to-dust mass ratio of 100. This characteristic density can be interpreted as the result of thermal pressure equilibrium between the molecular gas and the warm ambient interstellar medium. Such an equilibrium can plausibly be established since shear has approximately the same strength as self-gravity. Our findings may explain the fact that star formation in the CMZ is highly inefficient compared to the rest of the Milky Way disk. We also identify a population of clumps whose densities are two orders of magnitudes higher in the vicinity of the Sgr B2 region, which we propose are produced by collisions between the clumps of lower densities. For these collisions to occur, processes such as compressive tides probably have created the appropriate condition by assembling the clumps together.2020ApJ...897...89Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/897/89CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)J/A+A/487/993 : MAMBO Mapping of c2d Clouds and Cores (Kauffmann+, 2008)J/ApJ/721/137 : The Bolocam Galactic Plane Survey (BGPS) (Bally+, 2010)J/ApJ/723/492 : Physical properties of GRS molecular clouds (Roman-Duval+,2010)J/MNRAS/435/400 : ATLASGAL. Properties of compact HII regions (Urquhart+, 2013)J/A+A/565/A75 : ATLASGAL: dust condensations in Galactic plane (Csengeri+,2014)J/PASJ/67/90 : Central Molecular Zone in H^13^CO^+^ (Tsuboi+, 2015)J/A+A/586/A50 : Central Molecular Zone H2CO temperature maps (Ginsburg+, 2016)J/A+A/591/A149 : Hi-GAL. inner Milky Way: +68>=l>=70 (Molinari+, 2016)J/A+A/598/A76 : Six infrared dark clouds multi-wavelength obs. (Zhang+, 2017)J/A+A/619/A166 : SEDIGISM, kinematics of ATLASGAL filaments (Mattern+, 2018)J/ApJS/236/49 : CO and 850um obs. of Planck Galactic cold clumps (Zhang+, 2018)J/A+A/627/A85 : 8 massive proto-cluster clumps observations (Zhang+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/897/89https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/897/89http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/897/89https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/897/89https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/897/89http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/897/89GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/897/89/table1 (Parameters of identified Gaussian clumps)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/897/89/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/897/89/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/897/89/table1?GETtext/xml+votable180.050000true266.831584-28.3720450.0055555555555555565/7206 6/28828 28830-28831 28853 28874-2.439715709817298e-18 2.903888696868909e-18https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/897/89?format=asciiOpticalInfrareddefaultJ/ApJ/897/89/table1Parameters of identified Gaussian clumpsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClumps[1/1482] Clumps numbermeta.id;meta.mainintGLON[-2.01/2] Clump Galactic Longitudedegpos.galactic.lonGLAT[-0.41/0.41] Clump Galactic Latitudedegpos.galactic.latFWHM[19.3/117.8] Extracted clump sizearcsecphys.angSizefloatRad[0.45/2.74] Clump effective radiuspcphys.size.radiusfloatTdust[15.2/36.2] Dust temperatureKphys.temperaturefloate_Tdust[1.5/3.6] Uncertainty in TdustKstat.errorfloatF870[0.39/139.9] Peak 870um Flux DensityJy/beamphot.flux.densityfloatS870[0.54/405.4] Integrated 870um FluxJyphot.flux.density;em.opt.IfloatMH2[0.1/116] Mass in molecular hydrogen (1)1000solMassphys.massfloate_MH2[0.0/16.9] Uncertainty in MH21000solMassstat.errorfloatNH2[0.1/29] Molecular hydrogen column density (1)1e+23cm**-2phys.columnDensityfloate_NH2[0.0/4.0] Uncertainty in nH21e+23cm**-2stat.error;phys.columnDensityfloatn[0.1/51.9] Number density from S870um10000cm**-3meta.number;phys.densityfloate_n[0.0/7.2] Uncertainty in n10000cm**-3stat.errorfloat_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)degpos.eq.decnullableindexed