J/MNRAS/492/895ivo://CDS.VizieR/J/MNRAS/492/895doi:10.26093/cds/vizier.74920895CDSde la Fuente E.Porras A.Trinidad M.A.Kurtz S.E.Kemp S.N.,Tafoya D.Franco J.Rodriguez-Rico C.2024-08-20T20:16:00Z2023-05-23T15:34:32ZCDS support team

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

cds-question@unistra.frh-ii-regionsradio-continuum-emissioninterstellar-mediumIn this paper, we present the results of a morphological study performed on a sample of 28 ultracompact HII (UC HII) regions located near extended free-free emission, using radio continuum (RC) observations at 3.6cm with the C and D Very Large Array (VLA) configurations, with the aim of determining a direct connection between them. By using previously published observations in B and D VLA configurations, we compiled a final catalogue of 21 UC HII regions directly connected with the surrounding extended emission (EE). The observed morphology of most of the UC HII regions in RC emission is irregular (single- or multipeaked sources) and resembles a classical bubble structure in the Galactic plane with well-defined cometary arcs. RC images superimposed on colour composite Spitzer images reinforce the assignations of direct connection by the spatial coincidence between the UC components and regions of saturated 24{mu}m emission. We also find that the presence of EE may be crucial to understand the observed infrared excess because an underestimation of ionizing Lyman photons was considered in previous works (e.g. Wood & Churchwell; Kurtz, Churchwell & Wood).2020MNRAS.492..895Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/492/895CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/91/659 : Ultracompact HII regions radio images (Kurtz+ 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/492/895https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/492/895http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/492/895https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/492/895https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/492/895http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/492/895GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/492/895/table1 (The 28 ultracompact HII regions with extended emission)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/492/895/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/492/895/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/492/895/table1?GETtext/xml+votable180.050000true269.7620833-24.34847220.005555555555555556Cone search capability for table J/MNRAS/492/895/table5 (The final catalogue of UC HII + EE)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/492/895/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/492/895/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/492/895/table5?GETtext/xml+votable180.050000true269.762083-24.3484720.0055555555555555566/14309 14311 14358 14666 14696 15667 28890 28912 29091 29101 29505 29510 29533 29535 30219 30256 30263 30313 30319 30328 30420 30618 30622 30644 30691 30719https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/492/895?format=asciiRadiodefaultJ/MNRAS/492/895/table1The 28 ultracompact HII regions with extended emissionSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the HII region (GLLL.ll+BB.bb)meta.id;meta.maincharf_Name[c] Flag on Name (G1)meta.codecharONameIRAS name of the HII region (HHMMm+DDMMA)meta.id;obs.fieldcharRAJ2000Right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Declination (J2000) (1)pos.eq.dec;meta.mainDistDistancekpcpos.distancefloatr_Dist[1/6] Reference for Dist (2)meta.ref;pos.frameintJ/MNRAS/492/895/table2VLA observational parameters and UC HII fluxesf_Name[c] Flag on Name (G1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the HII region (GLLL.ll+BB.bb)meta.id;meta.maincharONameIRAS name of the HII region (HHMMm+DDMMA)meta.id;obs.fieldcharVLA[BCD] VLA configuration (1)instr.setupcharSnuIntegrated flux density (2)Jyphot.flux.density;em.radio.6-12GHzfloatBeam1Beam size, major axisarcsecphys.angSize;instr.beamfloatBeam2Beam size, minor axisarcsecphys.angSize;instr.beamfloatPA[] Position angledegpos.posAngintrmsObservational rmsmJy/beaminstr.det.noisefloatJ/MNRAS/492/895/table3Combined multiconfiguration VLA image parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the HII region (GLLL.ll+BB.bb)meta.id;meta.maincharf_Name[c] Flag on Name (1)meta.codecharONameIRAS name of the HII region (HHMMm+DDMMA)meta.id;obs.fieldcharVLAVLA configurations combined to produce the MRIsinstr.setupcharBeam1Beam size, major axisarcsecphys.angSize;instr.beamfloatBeam2Beam size, minor axisarcsecphys.angSize;instr.beamfloatPA[] Position angledegpos.posAngintrmsObservational rmsmJy/beaminstr.det.noisefloatJ/MNRAS/492/895/table4Results from morphological study of extended emissionRCpeaks[1/5] Number of radio continuum (RC) peaksmeta.numberintMorphTypeMorphological type according to Wood & Churchwell (1989ApJS...69..831W) (4)src.morph.typecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the HII region (GLLL.ll+BB.bb)meta.id;meta.maincharEE[YN] Presence of extended emission (Y:yes, N:No)meta.codecharConEElit[YPUN-] Indicates if there is a direct connection between the UC HII region and the large-scale extended emission (literature) (1)meta.codecharr_ConEElit[1/3]? Reference for ConEElit (2)meta.ref;pos.frameintnullableConEEtw[YPN] Indicates if there is a direct connection between the UC HII region and the large-scale extended emission (this work) (1)meta.codecharEEsize1Extended emission size (x-axis) (3)arcminphys.angSizefloatEEsize2Extended emission size (y-axis) (3)arcminphys.angSizefloatCh06/07[YN] Presence of Bubble-like structures from IRAC images according to Churchwell et al. (2006ApJ...649..759C, Cat. J/ApJ/649/759; 2007ApJ...670..428C, Cat. J/ApJ/670/428)meta.codecharSimp12[YN] Presence of Bubble-like structures from IRAC and MIPS images according to Simpson et al. (2012MNRAS.424.2442S, Cat. J/MNRAS/424/2442)meta.codecharBubble[YPN] Presence of Bubble-like structures according to this workmeta.codecharJ/MNRAS/492/895/table5The final catalogue of UC HII + EErecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the HII region (GLLL.ll+BB.bb)meta.id;meta.maincharf_Name[cd] Flag on Name (1)meta.codecharONameIRAS name of the HII region (HHMMm+DDMMA)meta.id;obs.fieldcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainDistDistancekpcpos.distancefloatr_Dist[1/5] Reference for Dist (2)meta.ref;pos.frameintSize1Size (x-axis)arcminphys.angSizefloatSize2Size (y-axis)arcminphys.angSize;instr.detfloatBubble[YP] Presence of Bubble-like structures (3)meta.codecharRCpeaks[1/5] Number of radio continuum (RC) peaksmeta.numberintJ/MNRAS/492/895/table6Results on the energetics for the initial sampleEElev[1/3]? Different levels at which EE reduces the values of f_d_ explaining the IR excess (1)meta.codeintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the HII region (GLLL.ll+BB.bb)meta.id;meta.maincharLIRASTotal luminosity measured via IRAS fluxes10000solLumphys.luminosityfloatlogN*cLogarithm of the ionizing photon rate N^*^_c_ (G2)log(s**-1)phys.luminosityfloatSpTypeISpectral type from IRAS observationssrc.spTypecharVLA[CD] VLA configurationinstr.setupcharlogN**cLogarithm of the ionizing photon rate N^**^_c_ (G3)log(s**-1)phys.luminosityfloatSpTyperSpectral type from radio observationssrc.spTypecharfd(CD)Fraction of UV photons absorbed by dust and hence without causing ionization for VLA C or D configurationmeta.numberfloatfd(B)? Fraction of UV photons absorbed by dust and hence without causing ionization for VLA B configurationmeta.numberfloatnullabler_fd(B)[1/2]? Reference for fd(B) (G4)meta.ref;pos.frameintnullableJ/MNRAS/492/895/table7Energetics results for the final cataloguerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameName of the HII region (GLLL.ll+BB.bb)meta.id;meta.maincharLIRASTotal luminosity measured via IRAS fluxes10000solLumphys.luminosityfloatlogN*cLogarithm of the ionizing photon rate N^*^_c_ (G2)log(s**-1)phys.luminosityfloatSpTypeISpectral type from IRAS observationssrc.spTypecharVLA[CD] VLA configurationinstr.setupcharlogN**cLogarithm of the ionizing photon rate N^**^_c_ (G3)log(s**-1)phys.luminosityfloatSpTyperSpectral type from radio observationssrc.spTypecharfd(B)? Fraction of UV photons absorbed by dust and hence without causing ionization for VLA B configurationmeta.numberfloatnullabler_fd(B)[1/2]? Reference for fd(B) (G4)meta.ref;pos.frameintnullablefd(CD)Fraction of UV photons absorbed by dust and hence without causing ionization for VLA C or D configurationmeta.numberfloat