J/A+A/563/A68ivo://CDS.VizieR/J/A+A/563/A68doi:10.26093/cds/vizier.35630068CDSChambers E.T.Yusef-Zadeh F.Ott J.2017-10-12T13:00:43Z2014-06-25T14:46:04ZCDS support team

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

cds-question@unistra.frastrophysical-masersradio-astronomyWe present a study of star formation in the central molecular zone (CMZ) of our Galaxy through the association of three star formation indicators: 6.7GHz CH_3_OH masers, 22GHz H_2_O masers, and enhanced 4.5{mu}m emission ('green') sources. We explore how star formation in the CMZ (|l|<1.3{deg}, |b|<10') compares with that of the Galactic disk (6{deg}>l>345{deg}, |b|<2{deg}). Using an automated algorithm, we search for green sources toward 6.7GHz CH_3_OH masers detected in the Parkes Methanol Multibeam Survey. We combine these results with lists of 22GHz H_2_O masers, including our Mopra survey of the CMZ. We find that the correlation of CH_3_OH masers with green sources is a function of Galactic latitude, with a minimum close to b=0 and increasing with |b| (toward the central part of the Galaxy, 6{deg}>l>345{deg}, |b|<2{deg}). We find no significant difference between the correlation rate of CH_3_OH masers with green sources in the CMZ and the disk. This suggests that although the physical conditions of the gas are different in the CMZ from that of the Galactic disk, once gravitational instability sets in at sufficiently high densities, signatures of star formation appear to be similar in both regions. Moreover, the detection of green sources, even at the distance of the Galactic center, shows that our technique can easily identify the early stages of star formation, especially in low-extinction regions of the Galaxy. Through the association of H_2_O and CH_3_OH masers, we identify 15 star-forming sites in the CMZ. We find a higher correlation rate of coincident H_2_O and CH_3_OH masers within the CMZ compared to the Galactic disk, indicating a difference in the maser evolutionary sequence for star-forming cores in these two regions.2014A&A...563A..68Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/563/A68CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/96 : 6-GHz methanol multibeam maser catalogue (Caswell+, 2010-12)J/MNRAS/416/1764 : H_2_O Southern Galactic Plane Survey (HOPS) (Walsh+, 2011)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/563/A68https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/563/A68http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/563/A68https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/563/A68https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/563/A68http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/563/A68GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/563/A68/table2 (H_2_O masers in the survey region)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/563/A68/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/563/A68/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/563/A68/table2?GETtext/xml+votable180.050000true266.83258-28.388360.005555555555555556Cone search capability for table J/A+A/563/A68/tableb1 (Association of green sources with CH_3_OH masers)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/563/A68/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/563/A68/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/563/A68/tableb1?GETtext/xml+votable180.050000true256.298512-41.4857890.005555555555555556Cone search capability for table J/A+A/563/A68/tableb2 (Association of H_2_O masers with CH_3_OH masers)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/563/A68/tableb2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/563/A68/tableb2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/563/A68/tableb2?GETtext/xml+votable180.050000true256.32433-41.348270.005555555555555556Cone search capability for table J/A+A/563/A68/tableb3 (CH_3_OH masers not associated with H_2_O masers)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/563/A68/tableb3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/563/A68/tableb3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/563/A68/tableb3?GETtext/xml+votable180.050000true256.29489-41.484730.005555555555555556Cone search capability for table J/A+A/563/A68/tableb4 (H_2_O masers not associated with CH_3_OH masers)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/563/A68/tableb4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/563/A68/tableb4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/563/A68/tableb4?GETtext/xml+votable180.050000true265.65212-30.102870.0055555555555555565/7206-7207 6/28808-28809 28811-28813 28874-28875 28896-28897 28900-28901 28912 28914 42390-42391 42396-42397 42434-42436 42438-42441 42444-42445 42450-42451 42454-42457 42460-42462https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/563/A68?format=asciiRadiodefaultJ/A+A/563/A68/table2H_2_O masers in the survey regionn_H2OSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintH2O[1/37] H_2_O maser sequential numbermeta.id;meta.mainintGLON[-2/2] Galactic longitude (1)degpos.galactic.lonGLATGalactic latitude (1)degpos.galactic.latVVelocity of peak maser emission (1)km/sspect.dopplerVelocfloatTpeakPeak intensity of the maserKphot.fluxfloatNvoNumber of voxels in the sourcemeta.numberint_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/A+A/563/A68/tableb1Association of green sources with CH_3_OH masersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCH3OHCH_3_OH maser name (GLLL.lll+B.bbbn) (1)meta.id;meta.maincharVpeakVelocity of peak maser emission (1)km/sspect.dopplerVelocfloatn_Vpeak[c] Note on Vpeak (2)meta.notecharGLONGalactic longitude from R peak (3)degpos.galactic.lonGLATGalactic latitude from R peak (3)degpos.galactic.latValueValue of the green pixel in each green source candidatemeta.numberfloatRbgBackground green value near each green source candidatemeta.numberfloatRcutGreen value used to define the boundary of the green source candidatemeta.numberfloatRtreshAverage green value for the pixels within the green source candidatemeta.numberfloatNpixNumber of pixel in the green source candidatemeta.numberintGreen[Y/N] Is the green source associated with a CH_3_OH maser ?meta.codecharC10Details from Caswell et al. 2010 (VIII/96)meta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/A+A/563/A68/tableb2Association of H_2_O masers with CH_3_OH masersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCH3OHCH_3_OH maser name (LLL.333+B.bbb)meta.id;meta.maincharVlowLower velocity limit of the CH_3_OH maser (1)km/sspect.dopplerVelocfloatVhighHigher velocity limit of the CH_3_OH maser (1)km/sspect.dopplerVelocfloatNNumber of H_2_O masers associatedmeta.numberintnullableGLONH_2_O maser Galactic longitudedegpos.galactic.lonGLATH_2_O maser Galactic latitudedegpos.galactic.latVH2OVelocity of the H_2_O peak emissionkm/sspect.dopplerVelocfloatr_VH2OReference for VH2O (2)meta.ref;pos.frameintSep[1/70] Angular separation between the associated CH_3_OH and H_2_O masersarcsecpos.angDistanceintGreen[Y/N] Is the CH_3_OH maser associated with a green source ?meta.codecharC10Details from Caswell et al. 2010 (VIII/96)meta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/A+A/563/A68/tableb3CH_3_OH masers not associated with H_2_O masersl_SpeakLimit flag on Speakmeta.code.errorcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCH3OHCH_3_OH maser name (LLL.lll+B.bbbn)meta.id;meta.maincharGLONCH_3_OH maser Galactic longitudedegpos.galactic.lonGLATCH_3_OH maser Galactic latitudedegpos.galactic.latVlowLower velocity limit of the CH_3_OH maser (1)km/sspect.dopplerVelocfloatVhighHigher velocity limit of the CH_3_OH maser (1)km/sspect.dopplerVelocfloatSpeakPeak intensity of CH_3_OH maser emissionJyphot.flux.density;em.radio.1500-3000MHzfloatn_Speak[b] Note on Speak (2)meta.notecharGreen[Y/N] Is the CH_3_OH maser is associated with a green source?meta.codechar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexedJ/A+A/563/A68/tableb4H_2_O masers not associated with CH_3_OH masersFpeak? Peak emission of the maser (in Jy)Jyphot.flux.density;em.radio.1500-3000MHzfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintr_H2OReference for H2O maser name (1)meta.ref;pos.framecharH2OH_2_O maser name or numbermeta.id;meta.maincharGLONH_2_O maser Galactic longitudedegpos.galactic.lonGLATH_2_O maser Galactic latitudedegpos.galactic.latVH2OVelocity of the H_2_O peak emission of the maserkm/sspect.dopplerVelocfloatTpeak? Peak emission of the maser (in K)Kphot.flux.density;em.radio.1500-3000MHzfloatnullable_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data)degpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data)degpos.eq.decnullableindexed