J/MNRAS/291/261ivo://CDS.VizieR/J/MNRAS/291/261doi:10.26093/cds/vizier.72910261CDSWalsh A.J.Hyland A.R.Robinson G.Burton M.G2024-06-25T20:17:51Z1998-03-05T22:11:58ZCDS support team

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

cds-question@unistra.frh-ii-regionsastrophysical-masersradio-astronomyradial-velocityA survey of ultracompact (UC) HII regions has been carried out by searching for 6.669-GHz methanol maser emission from a sample of 535 IRAS-selected candidates. A total of 201 candidates exhibit methanol emission. These sources have been used, in conjunction with previously identified UC HII regions, to provide a base for further studies of such regions. Estimates of distances have indicated that the identified UC HII regions tend to have some Galactic structure but it is not clear whether they lie in or between the spiral arms of the Galaxy. The regions are tightly constrained to the plane of the Galaxy. Comparison of identified regions and IRAS sources selected by Wood & Churchwell indicates that there there is some degree of contamination, which could be due to an older phase in the life on an UC HII region where methanol maser emission is not apparent. Luminosities and spectral types have been derived for many of the regions. The maximum number of maser spots observed seems to increase with increasing peak maser luminosity, which indicates that the maser emission is more dependent on the abundance of methanol than the availability of far-infrared radiation.1997MNRAS.291..261Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/291/261CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/91/659 : Ultracompact HII regions radio images (Kurtz+ 1994)J/A+AS/110/81 : Methanol masers towards IRAS sources (van der Walt+ 1995)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/291/261https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/291/261http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/291/261https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/291/261https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/291/261http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/291/261GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/291/261/table2 (List of the 215 candidates identified as UC H II regions)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/291/261/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/291/261/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/291/261/table2?GETtext/xml+votable180.050000true85.44116-1.90870.0055555555555555565/7207 10624 6/21458 21510 22855 28808-28809 28812 28824 28827 28890 28896 28912-28913 28918-28919 29070 29090-29092 29094 29096-29097 29100-29101 29103 29113 29115-29116 29160 29461 29505 29508 29510-29511 29529 29532-29533 29535 30218-30219 30241 30256 30258-30259 30262-30263 30268-30269 30312 37244 37839 37846 37850 37886 37897 37900 37923 37938 38020 38024 39251 39282 41597 41653 41655 41671 41677 41681 41683-41685 41696 41758-41759 41765-41766 41770 41772 41776-41778 41780 41799 41804 41814-41815 41820 41824 42159 42169-42172 42174 42207 42211 42214-42215 42224-42226 42228-42229 42382 42387 42390-42391 42393 42396-42397 42417 42436 42438 42441 42444-42445 42451 42454-42456 42460-42461 43013 43015 43019 43021 43024 43041https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/291/261?format=asciiOpticalRadiodefaultJ/MNRAS/291/261/table1IRAS sources in our data set with no positive methanol identification, and no other defining UC H II characteristicsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIRASIRAS PSC name (Cat. <II/125>)meta.id;meta.maincharJ/MNRAS/291/261/table2List of the 215 candidates identified as UC H II regionsLtot2? Calculated total Luminosity for IRAS fluxes from Dist2 value10000solLumphys.luminosityfloatnullableSpTypeSpectral type of single star responsible for emission in Ltotsrc.spTypecharSpType2Spectral type of single star responsible for emission in Ltot2meta.curation;src.spTypecharAss1[MNOUW] Other association (6)meta.notecharr_Ass1Source of Ass1 (7)meta.ref;pos.framecharAss2[MNOUWx] Other association (6)meta.notecharr_Ass2Source of Ass2 (7)meta.ref;pos.framecharAss3[MOUWx] Other association (6)meta.notecharr_Ass3Source of Ass3 (7)meta.ref;pos.framecharAss4[W] Other association (6)meta.notecharr_Ass4Source of Ass4 (7)meta.ref;pos.framechar_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.decnullableindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIRASIRAS PSC name (Cat. <II/125>)meta.id;meta.maincharGLONGalactic longitude of pointing centre (1)degpos.galactic.lonGLATGalactic latitude of pointing centre (1)degpos.galactic.latPeak? Peak flux density of methanol maser emissionJyphot.flux.density;em.radio.6-12GHzfloatnullablen_Peak[abg ] Note on observation of Peak (2)meta.notecharRV? Radial velocity of Peak maser componentkm/sphys.veloc;pos.heliocentricfloatnullableVinf? Velocity range over which maser emission is seen (lower value)km/sphys.veloc;phys.emissMeasureintnullableVsup? Velocity range over which maser emission is seen (upper value)km/sphys.veloc;phys.emissMeasureintnullablen_Vsup[d] Note on Velocity range (3)meta.notecharNpeak? Number of maser peaks observed in each spectrummeta.numberintnullableDist? Adopted kinematic distance (4)kpcpos.distancefloatnullableDist2?Second kinematic distance when ambiguitykpcpos.distancefloatnullabler_Dist[iez] Source of Dist (5)meta.ref;pos.framecharLtot? Calculated total luminosity for IRAS fluxes form Dist value10000solLumphys.luminositydoublenullable