J/ApJ/961/4ivo://CDS.VizieR/J/ApJ/961/4CDSBudaiev N.Ginsburg A.Jeff D.Goddi C.Meng F.Sanchez-Monge A.,Schilke P.Schmiedeke A.Yoo T.2026-04-28T07:27:02Z2026-04-28T08:05:05ZCDS support team

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

cds-question@unistra.frmillimeter-astronomyphotometrysubmillimeter-astronomyyoung-stellar-objectsstellar-massesstar-forming-regionsastronomical-object-identificationWe present 500 and 700au resolution 1 and 3mm Atacama Large Millimeter/submillimeter Array observations, respectively, of protostellar cores in protoclusters Sagittarius B2 (Sgr B2) North (N) and Main (M), parts of the most actively star-forming cloud in our Galaxy. Previous lower-resolution (5000au) 3mm observations of this region detected ~150 sources inferred to be young stellar objects (YSOs) with M>8M_{sun}_. With a 10-fold increase in resolution, we detect 371 sources at 3mm and 218 sources in the smaller field of view at 1mm. The sources seen at low resolution are observed to fragment into an average of two objects. About one-third of the observed sources fragment. Most of the sources we report are marginally resolved and are at least partially optically thick. We determine that the observed sources are most consistent with Stage 0/I YSOs, i.e., rotationally supported disks with an active protostar and an envelope, that are warmer than those observed in the solar neighborhood. We report source-counting-based inferred stellar mass and the star formation rate of the cloud: 2800M_{sun}_ and 0.0038M_{sun}_/yr for Sgr B2 N and 6900M_{sun}_ and 0.0093M_{sun}_/yr for Sgr B2 M, respectively.2024ApJ...961....4Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/961/4CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/291/943 : Protostellar cores (Ossenkopf+, 1994)J/AJ/139/1695 : Celestial Reference Frame at 24 and 43 GHz (Lanyi+, 2010)J/A+A/586/A50 : Central Molecular Zone H2CO temperature maps (Ginsburg+, 2016)J/A+A/604/A6 : SgrB2 ALMA continuum and spectral index (Sanchez-Monge+, 2017)J/ApJ/869/L41 : DSHARP I. Sample, ALMA obs. log and overview (Andrews+, 2018)J/ApJ/853/171 : mm point sources in the extended Sgr B2 cloud (Ginsburg+, 2018)J/ApJ/890/130 : VANDAM survey of Orion protostars. II. (Tobin+, 2020)J/ApJ/923/221 : ALMA obs. of protoplanetary disks in ONC & OMC1 (Otter+, 2021)J/A+A/666/A31 : Sgr B2 UCHII regions in 6, 22.4 and 96GHz (Meng+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/961/4https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/961/4http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/961/4https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/961/4https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/961/4http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/961/4GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/961/4/table4a (Sgr B2 M ALMA 3mm (Band 3) continuum catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/4/table4a?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/4/table4a?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/4/table4a?GETtext/xml+votable180.050000true266.83381-28.385110.005555555555555556Cone search capability for table J/ApJ/961/4/table4b (Sgr B2 M ALMA 1mm (Band 6) continuum catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/4/table4b?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/4/table4b?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/4/table4b?GETtext/xml+votable180.050000true266.83397-28.384750.005555555555555556Cone search capability for table J/ApJ/961/4/table4c (Sgr B2 N ALMA 3mm (Band 3) continuum catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/4/table4c?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/4/table4c?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/4/table4c?GETtext/xml+votable180.050000true266.83285-28.372310.005555555555555556Cone search capability for table J/ApJ/961/4/table4d (Sgr B2 N ALMA 1mm (Band 6) continuum catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/4/table4d?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/4/table4d?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/4/table4d?GETtext/xml+votable180.050000true266.83304-28.372020.0055555555555555566/28830https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/961/4?format=asciiMillimeterdefaultJ/ApJ/961/4/table4aSgr B2 M ALMA 3mm (Band 3) continuum catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/361] Source IDmeta.id;meta.mainintRAJ2000[17] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[28] Degree of Declination (J2000)pos.eq.dec;meta.mainScore[0/2] 2 = core, 1 = likely core (G1)meta.code.classintOTypeSource type (1)src.classcharIDG18[71/271]? Source ID match from G18 (Ginsburg+ 2018, J/ApJ/853/171) catalogmeta.id.crossintnullableSnuF[0.07/728] Dendrogram contour fluxmJyphot.flux.densityfloatSnuPk[0.25/187] Brightest pixel fluxmJy/beamphot.flux.density;instr.pixel;stat.maxfloatErrSnu[0.05/0.2] NoisemJy/beaminstr.det.noisefloatFWHMmaj[0.036/0.31] Source FWHM (maj)arcsecphys.angSizefloatFWHMmin[0.02/0.23] Source FWHM (min)arcsecphys.angSizefloatOIDG18Source OID match from G18 (Ginsburg+ 2018, J/ApJ/853/171) catalogmeta.id.crosscharIDB6[4/301]? Source ID match from Band 6meta.idintnullableTB[4/3766] Brightness temperatureKphys.temperatureintalpha[-1.1/3.5]? Spectral indexspect.indexfloatnullablee_alpha[0.002/0.4]? Uncertainty on spectral indexstat.error;spect.indexfloatnullableMass[2.2/240.7]? Core masssolMassphys.massfloatnullableJ/ApJ/961/4/table4bSgr B2 M ALMA 1mm (Band 6) continuum catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[4/301] Source IDmeta.id;meta.mainintSnuF[0.5/635] Dendrogram contour fluxmJyphot.flux.densityfloatSnuPk[1.3/146] Brightest pixel fluxmJy/beamphot.flux.density;instr.pixel;stat.maxfloatErrSnu[0.2/1.1] NoisemJy/beaminstr.det.noisefloatFWHMmaj[0.028/0.35] Source FWHM (maj)arcsecphys.angSizefloatFWHMmin[0.014/0.16] Source FWHM (min)arcsecphys.angSizefloatRAJ2000[17] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[28] Degree of Declination (J2000)pos.eq.dec;meta.mainScore[0/2] 2 = core, 1 = likely core (G1)meta.code.classintOTypeSource type (1)src.classcharIDB3[1/256]? Source ID match from Band 3meta.idintnullableTB[9/1097] Brightness temperatureKphys.temperatureintalpha[-1/3.7] Spectral indexspect.indexfloate_alpha[0.002/0.4] Uncertainty on spectral indexstat.error;spect.indexfloatMass[0.6/72.6]? Core masssolMassphys.massfloatnullableJ/ApJ/961/4/table4cSgr B2 N ALMA 3mm (Band 3) continuum catalogFWHMmaj[0.03/0.3] Source FWHM (maj)arcsecphys.angSizefloatFWHMmin[0.019/0.3] Source FWHM (min)arcsecphys.angSizefloatTB[3/834] Brightness temperatureKphys.temperatureintalpha[-1.05/4.5]? Spectral indexspect.indexfloatnullablee_alpha[0.02/0.4]? Uncertainty on spectral indexstat.error;spect.indexfloatnullableMass[1/163]? Core masssolMassphys.massfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/397] Source IDmeta.id;meta.mainintSnuF[0.04/58.1] Dendrogram contour fluxmJyphot.flux.densityfloatSnuPk[0.16/41.3] Brightest pixel fluxmJy/beamphot.flux.density;instr.pixel;stat.maxfloatErrSnu[0.03/0.07] NoisemJy/beaminstr.det.noisefloatRAJ2000[17] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[28] Degree of Declination (J2000)pos.eq.dec;meta.mainScore[0/2] 2 = core, 1 = likely core (G1)meta.code.classintOTypeSource type (1)src.classcharIDG18[96/252]? Source ID match from G18 (Ginsburg+ 2018, J/ApJ/853/171) catalogmeta.id.crossintnullableOIDG18Source OID match from G18 (Ginsburg+ 2018, J/ApJ/853/171) catalogmeta.id.crosscharIDB6[1/340]? Source ID match from Band 6meta.idintnullableJ/ApJ/961/4/table4dSgr B2 N ALMA 1mm (Band 6) continuum catalogrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/340] Source IDmeta.id;meta.mainintSnuF[0.8/133] Dendrogram contour fluxmJyphot.flux.densityfloatSnuPk[1.8/54.7] Brightest pixel fluxmJy/beamphot.flux.density;instr.pixel;stat.maxfloatErrSnu[0.3/1.2] NoisemJy/beaminstr.det.noisefloatFWHMmaj[0.03/0.31] Source FWHM (maj)arcsecphys.angSizefloatFWHMmin[0.014/0.2] Source FWHM (min)arcsecphys.angSizefloatRAJ2000[17] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[28] Degree of Declination (J2000)pos.eq.dec;meta.mainScore[1/2] 2 = core, 1 = likely core (G1)meta.code.classintOTypeSource type (1)src.classcharIDB3[2/323]? Source ID match from Band 3meta.idintnullableTB[13/409] Brightness temperatureKphys.temperatureintalpha[-1.01/4.3] Spectral indexspect.indexfloate_alpha[0.01/0.4] Uncertainty on spectral indexstat.error;spect.indexfloatMass[0.8/39.7]? Core masssolMassphys.massfloatnullable