J/A+A/666/L15ivo://CDS.VizieR/J/A+A/666/L15doi:10.26093/cds/vizier.36669015CDSYan Y.T.Henkel C.Menten K.M.Gong Y.Nguyen H.Ott J.Ginsburg A.,Wilson T.L.Brunthaler A.Belloche A.Zhang J.S.Budaiev N.Jeff D.2023-03-29T13:12:57Z2023-02-22T14:07:07ZCDS support team

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

cds-question@unistra.frmolecular-cloudsradio-astronomyastrophysical-masersWe report the discovery of widespread maser emission in non-metastable inversion transitions of NH_3_ toward various parts of the Sagittarius B2 molecular cloud and star-forming region complex. We detect masers in the J, K = (6, 3), (7,4), (8,5), (9,6), and (10,7) transitions toward Sgr B2(M) and Sgr B2(N), an NH_3_ (6,3) maser in Sgr B2(NS), and NH_3_ (7,4), (9,6), and (10,7) masers in Sgr B2(S). With the high angular resolution data of the Karl G. Jansky Very Large Array (JVLA) in the A-configuration, we identify 18 maser spots. Nine maser spots arise from Sgr B2(N), one from Sgr B2(NS), five from Sgr B2(M), and three in Sgr B2(S). Compared to our Effelsberg single-dish data, the JVLA data indicate no missing flux. The detected maser spots are not resolved by our JVLA observations. Lower limits to the brightness temperature are >3000K and reach up to several 10^5^K, manifesting the lines' maser nature. In view of the masers' velocity differences with respect to adjacent hot molecular cores and/or UCHII regions, it is argued that all the measured ammonia maser lines may be associated with shocks caused either by outflows or by the expansion of UCHII regions. Overall, Sgr B2 is unique in that it allows us to measure many NH_3_ masers simultaneously, which may be essential in order to elucidate their thus far poorly understood origin and excitation.2022A&A...666L..15Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/666/L15CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/666/L15https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/666/L15http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/666/L15https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/666/L15https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/666/L15http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/666/L15GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/666/L15/tableb5 (1.6cm JVLA flux densities of individual continuum sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/666/L15/tableb5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/666/L15/tableb5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/666/L15/tableb5?GETtext/xml+votable180.050000true266.83302917-28.384120.005555555555555556Cone search capability for table J/A+A/666/L15/tableb6 (NH_3_ maser positions in Sgr B2, derived from the JVLA observations.)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/666/L15/tableb6?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/666/L15/tableb6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/666/L15/tableb6?GETtext/xml+votable180.050000true266.83335417-28.371468060.0055555555555555566/288301.241528518768467e-23 1.241528518768467e-23https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/666/L15?format=asciiRadiodefaultJ/A+A/666/L15/tableb51.6cm JVLA flux densities of individual continuum sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource namemeta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.maine_RAJ2000Right ascension errorsstat.error;pos.eq.rafloatDEJ2000Declination (J2000)pos.eq.dec;meta.maine_DEJ2000Declination errorarcsecstat.error;pos.eq.decfloate_Size1? Deconvolved size errorarcsecstat.error;pos.distance;phys.sizefloatnullablel_Size1[-] Limit flag on Size1meta.code.error;pos.distance;phys.sizecharSize1Deconvolved sizearcsecphys.angSizefloatl_Size2[-] Limit flag on Size2meta.code.error;pos.distance;phys.sizecharSize2Deconvolved sizearcsecphys.angSizefloate_Size2? Deconvolved size errorarcsecstat.error;pos.distance;phys.sizefloatnullablePA? Position angledegpos.posAngfloatnullableSnu1.6cm JVLA flux densitymJyphot.flux.density;em.radiointe_Snu1.6cm JVLA flux density errormJystat.errorfloatJ/A+A/666/L15/tableb6NH_3_ maser positions in Sgr B2, derived from the JVLA observations.recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTransTransitionmeta.id;phys.atmol.transitioncharMaserNH_3_ maser namemeta.id;meta.maincharn_MaserNote on Maser (1)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.maine_RAJ2000Right ascension errorsstat.error;pos.eq.rafloatDEJ2000Declination (J2000)pos.eq.dec;meta.maine_DEJ2000Declination errorarcsecstat.error;pos.eq.decfloatSnuJLVA 1.6bm fluxJy/beamphot.flux.density;em.radiofloatTMBMean brigthness temperature10000Kphys.temperaturefloatVLSRLSR velocitykm/sphys.veloc;pos.lsrfloate_VLSRLSR velocity errorkm/sstat.error;phys.veloc;pos.lsrfloatDeltaV1/2Average value of the FWHM of the linekm/sspect.line.widthfloate_DeltaV1/2Average value of the FWHM of the line errorkm/sstat.errorfloat