J/A+A/602/A37ivo://CDS.VizieR/J/A+A/602/A37doi:10.26093/cds/vizier.36020037CDSKim W.-J.Wyrowski F.Urquhart J.S.Menten K.M.Csengeri T.2019-05-09T15:19:08Z2017-06-02T07:00:01ZCDS support team

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

cds-question@unistra.frmolecular-cloudsh-ii-regionsinterstellar-mediumradio-astronomymillimeter-astronomysubmillimeter-astronomyObservations of millimeter wavelength radio recombination lines (mm-RRLs) are used to search for HII regions in an unbiased way that is complementary to many of the more traditional methods previously used (e.g., radio continuum, far-infrared colors, maser emission). The mm-RRLs can be used to derive physical properties of HII regions and to provide velocity information of ionized gas. We carried out targeted mm-RRL observations (39<= principal quantum number (n) <=65 and {Delta}n = 1, 2, 3, and 4, named Hn{alpha}, Hn{beta}, Hn{gamma}, and Hn{delta}) using the IRAM 30m and Mopra 22m telescopes. In total, we observed 976 compact dust clumps selected from a catalog of ~10000 sources identified by the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL). The sample was selected to ensure a representative mix of star-forming and quiescent clumps such that a variety of different evolutionary stages is represented. Approximately half of the clumps are mid-infrared quiet while the other half are mid-infrared bright. We detected Hn{alpha} mm-RRL emission toward 178 clumps; Hn{beta}, Hn{gamma}, and Hn{delta} were also detected toward 65, 23, and 22 clumps, respectively. This is the largest sample of mm-RRLs detections published to date. Comparing the positions of these clumps with radio continuum surveys we identified compact radio counterparts for 134 clumps, confirming their association with known HII regions. The nature of the other 44 detections is unclear, but 8 detections are thought to be potentially new HII regions while the mm-RRL emission from the others may be due to contamination from nearby evolved HII regions. Broad linewidths are seen toward nine clumps (linewidth>40km/s) revealing significant turbulent motions within the ionized gas; in the past, such wide linewidths were found toward very compact and dense HII regions. We find that the systemic velocity of the associated dense molecular gas, traced by H^13^CO^+^(1-0), is consistent with the mm-RRL velocities and confirms them as embedded HII regions. We also find that the linewidth of the H^13^CO^+^(1-0) emission is significantly wider than those without mm-RRL detection, indicating a physical connection between the embedded H II region and their natal environments. We also find a correlation between the integrated fluxes of the mm-RRLs and the 6cm continuum flux densities of their radio counterparts (the correlation coefficient, {rho}, is 0.70). By calculating the electron densities we find that the mm-RRL emission is associated with HII regions with n_e_<10^5^cm^3^ and HII region diameter >0.03pc. We detected mm-RRLs toward 178 clumps and identified eight new HII region candidates. The broad mm-RRL from nine clumps may indicate that they arise in very young hyper-compact HII regions. The mm-RRLs trace the radio continuum sources detected by high-resolution observations and their line parameters show associations with the embedded radio sources and their parental molecular clumps.2017A&A...602A..37Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/602/A37CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/549/A45 : ATLASGAL. Compact Source Catalog: 330<l<21 (Contreras+, 2013)J/MNRAS/435/400 : ATLASGAL. Properties of compact HII regions (Urquhart+, 2013)J/A+A/568/A41 : ATLASGAL. Compact Source Catalog: 280<l<60 (Urquhart+, 2014)J/A+A/586/A149 : SiO in ATLASGAL-selected massive clumps (Csengeri+, 2016)J/A+A/599/A139 : ATLASGAL massive clumps dust characterization (Koenig+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/602/A37https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/602/A37http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/602/A37https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/602/A37https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/602/A37http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/602/A37GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/602/A37/table3 (Detail information of dust clumps that have recombination line detections)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/602/A37/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/602/A37/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/602/A37/table3?GETtext/xml+votable180.050000true271.579167-21.6244440.0055555555555555566/28919 29090-29091 29094 29097 29101 29112 29114 29116 29118 29463 29504-29505 29508 30218 30256 30259 30262-30263 30268-30269 30312-30313 30318-30319 30405 30420 30616-30618 30622 30644 30691 30694 41655 41681 41683 41772 41777 41780 41799 41804-41805 41811-41813 41817 41820 41824 42158-42159 42169-42170 42172 42174 42214-42215 42224-42225 42376 42382 42387 42391 42393 42396-42397 42435-42436 42438-42439 42441 42445 42447 42451 42454-42457 42460 42462 42496 42498 43013 430213.313034785154005e-24 9.029279001593864e-21https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/602/A37?format=asciiMillimeterRadiodefaultJ/A+A/602/A37/table3Detail information of dust clumps that have recombination line detectionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqATLASGAL clump numbermeta.idintprimaryNameATLASGAL clump namemeta.id;meta.maincharRAJ2000Right Ascension J2000pos.eq.ra;meta.mainDEJ2000Declination J2000pos.eq.dec;meta.mainDist? Heliocentric distancekpcpos.distancefloatnullablelogM? Log of the clump masslog(solMass)phys.massfloatnullablelogLbol? Log of bolometric luminositylog(solLum)phys.luminosityfloatnullableRRLVlsrLSR velocity of recombination linekm/sphys.recombination.coeff;pos.lsrintsysVlsrLSR systemic velocity of clumpskm/sphys.velocintmid-IRAssociation with mid-IR emissionmeta.codecharRadio[YCN] Association with radio continuum emission (1)meta.codecharCommComments about other informationsmeta.notecharwisemeta.ref.urlchariracmeta.ref.urlcharspectrummeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/602/A37/table2_2Line parameters of hydrogen beta RRLsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqATLASGAL clump numbermeta.idintNameATLASGAL clump namemeta.id;meta.maincharTint(Hnb)Hnb RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloate_Tint(Hnb)rms uncertainty on Tint(Hnb)K.km/sstat.errorfloatv(Hnb)LSR velocity of Hnb RRLkm/sspect.dopplerVeloc;pos.lsrfloate_v(Hnb)rms uncertainty on v(Hnb)km/sstat.errorfloatdv(Hnb)Hnb linewidthkm/sspect.line.widthfloate_dv(Hnb)rms uncertainty on dv(Hnb)km/sstat.errorfloatTpeak(Hnb)Hnb RRL peak intensity on Ta* scaleKinstr.scalefloatrmsrms noise per channelKstat.stdev;instr.det.noisefloatTint(H48b)? H48b RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H48b)? H48b linewidthkm/sspect.line.widthfloatnullableTint(H49b)? H49b RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H49b)? H49b linewidthkm/sspect.line.widthfloatnullableTint(H50b)? H50b RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H50b)? H50b linewidthkm/sspect.line.widthfloatnullableTint(H51b)? H51b RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H51b)? H51b linewidthkm/sspect.line.widthfloatnullableTint(H52b)? H52b rRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H52b)? H52b linewidthkm/sspect.line.widthfloatnullableJ/A+A/602/A37/table2_3Line parameters of hydrogen gamma RRLsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqATLASGAL clump numbermeta.idintNameATLASGAL clump namemeta.id;meta.maincharTint(Hng)Hng RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloate_Tint(Hng)rms uncertainty on Tint(Hng)K.km/sstat.errorfloatv(Hng)LSR velocity of Hng RRLkm/sspect.dopplerVeloc;pos.lsrfloate_v(Hng)rms uncertainty on v(Hng)km/sstat.errorfloatdv(Hng)Hng linewidthkm/sspect.line.widthfloate_dv(Hng)rms uncertainty on dv(Hng)km/sstat.errorfloatTpeak(Hng)Hng RRL peak intensity on Ta* scaleKinstr.scalefloatrmsrms noise per channelKstat.stdev;instr.det.noisefloatTint(H55g)? H55g RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H55g)? H55g linewidthkm/sspect.line.widthfloatnullableTint(H56g)? H56g RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H56g)? H56g linewidthkm/sspect.line.widthfloatnullableTint(H57g)? H57g RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H57g)? H57g linewidthkm/sspect.line.widthfloatnullableTint(H58g)? H58g RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H58g)? H58g linewidthkm/sspect.line.widthfloatnullableTint(H60g)? H60g RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H60g)? H60g linewidthkm/sspect.line.widthfloatnullableJ/A+A/602/A37/table2_4Line parameters of hydrogen delta RRLsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqATLASGAL clump numbermeta.idintNameATLASGAL clump namemeta.id;meta.maincharTint(Hnd)Hnd RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloate_Tint(Hnd)rms uncertainty on Tint(Hnd)K.km/sstat.errorfloatv(Hnd)LSR velocity of Hnd RRLkm/sspect.dopplerVeloc;pos.lsrfloate_v(Hnd)rms uncertainty on v(Hnd)km/sstat.errorfloatdv(Hnd)Hnd linewidthkm/sspect.line.widthfloate_dv(Hnd)rms uncertainty on dv(Hnd)km/sstat.errorfloatTpeak(Hnd)Hnd RRL peak intensity on Ta* scaleKinstr.scalefloatrmsrms noise per channelKstat.stdev;instr.det.noisefloatTint(H60d)? H60d RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H60d)? H60d linewidthkm/sspect.line.widthfloatnullableTint(H61d)? H61d RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H61d)? H61d linewidthkm/sspect.line.widthfloatnullableTint(H62d)? H62d RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H62d)? H62d linewidthkm/sspect.line.widthfloatnullableTint(H63d)? H63d RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H63d)? H63d linewidthkm/sspect.line.widthfloatnullableTint(H64d)? H64d RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H64d)? H64d linewidthkm/sspect.line.widthfloatnullableTint(H65d)? H65d RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H65d)? H65d linewidthkm/sspect.line.widthfloatnullableJ/A+A/602/A37/table2_1Line parameters of hydrogen alpha RRLsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqATLASGAL clump numbermeta.idintNameATLASGAL clump name (AGALlll.lll+bb.bbb)meta.id;meta.maincharTint(Hna)Hna RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloate_Tint(Hna)rms uncertainty on Tint(Hna)K.km/sstat.errorfloatv(Hna)LSR velocity of Hna RRLkm/sspect.dopplerVeloc;pos.lsrfloate_v(Hna)rms uncertainty on v(Hna)km/sstat.errorfloatdv(Hna)Hna linewidthkm/sspect.line.widthfloate_dv(Hna)rms uncertainty on dv(Hna)km/sstat.errorfloatTpeak(Hna)Hna RRL peak intensity on Ta* scaleKinstr.scalefloatrmsrms noise per channelKstat.stdev;instr.det.noisefloatTint(H39a)? H39a RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H39a)? H39a linewidthkm/sspect.line.widthfloatnullableTint(H40a)? H40a RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H40a)? H40a linewidthkm/sspect.line.widthfloatnullableTint(H41a)? H41a RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H41a)? H41a linewidthkm/sspect.line.widthfloatnullableTint(H42a)? H42a RRL integrated intensity on Ta* scaleK.km/sinstr.scalefloatnullabledv(H42a)? H42a linewidthkm/sspect.line.widthfloatnullableJ/A+A/602/A37/table6Properties of radio continuum and mid-IR emission toward dust clumps with mm-RRLsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqATLASGAL clump numbermeta.idintNameATLASGAL clump namemeta.id;meta.maincharFpeakRadio continuum peak flux at 5GHzJy/beamphot.flux.density;em.radio.3-6GHzfloatFintRadio continuum integrated flux at 5GHzJyphot.flux.density;em.radio.3-6GHzfloatDiamRadio continuum angular diameterarcsecphys.angSize;em.radio;spect.continuumfloatF22? 22um emission fluxJyphot.flux.density;em.IR.15-30umfloatnullableDist? Heliocentric distancekpcpos.distancefloatnullable