J/A+A/679/A123ivo://CDS.VizieR/J/A+A/679/A123doi:10.26093/cds/vizier/bc-n7/lbcdCDSKim W.-J.Urquhart J.S.V.S.VeenaFuller G.A.Schilke P.Kim K-T2026-07-01T14:01:10Z2023-11-22T10:05:28ZCDS support team

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

cds-question@unistra.frsurveysstar-forming-regionsh-ii-regionsmolecular-cloudsradio-astronomyThe application of silicon monoxide (SiO) as a shock tracer arises from its propensity to occur in the gas phase as a result of shock-induced phenomena, including outflow activity and interactions between molecular clouds and expanding HII regions or supernova remnants. Here we search for indications of shocks toward 366 massive star-forming regions by observing the ground rotational transition of SiO (v=0, J=1-0) at 43GHz with the Korean VLBI Network (KVN) 21m telescopes to extend our understanding on the origins of SiO in star-forming regions. We analyze the thermal SiO 1-0 emission and compare the properties of SiO emission with the physical parameters of associated massive dense clumps as well as 22GHz H_2_O and Class I 44GHz CH_3_OH maser emission. We detect SiO emission toward 104 regions which consist of 57 IRDCs, 21 HMPOs, and 26 UCHIIs. Out of 104 sources, 71 and 80 sources have 22GHz H_2_O and 44GHz Class I CH_3_OH maser counterparts, respectively. The determined median SiO column density, N(SiO), and abundance, X(SiO), relative to N(H_2_) are 8.12x10^12^cm^-2^ and 1.28x10^-10^, respectively. These values are similar to those obtained toward other star-forming regions and also consistent with predicted values from shock models with low-velocity shocks (<~10-15km/s). For sources with dust temperatures (T_dust_)<~20K, we find that N(SiO) and X(SiO) derived with the J=1-0 transition are a factor ~3 larger than those from the previous studies obtained with SiO 2-1. While the X(SiO) does not exhibit any strong correlation with the evolutionary stages of their host clumps, L_SiO_ is highly correlated with dust clump mass, and L_SiO_/L_bol_ also has a strong negative correlation with Tdust. This shows that colder and younger clumps have high L_SiO_/L_bol_ suggestive of an evolutionary trend. This trend is not due to excess emission at higher velocities, such as SiO wing features, as the colder sources with high L_SiO_/L_bol_ ratios lack wing features. Comparing with H_2_O and Class I CH_3_OH masers, we find a significant correlation between L_SiO_/L_bol_ and L_CH_3_OH_/L_bol_ ratios, whereas no similar correlation is seen for the H_2_O maser emission. This suggests a similar origin for the SiO and Class I CH_3_OH emission in these sources. We demonstrate that in cold regions SiO J=1-0 may be a better tracer of shocks than higher J transition of SiO. Lower Tdust (and so probably. less globally evolved) sources appear to have higher L_SiO_ relative to their L_bol_. The SiO 1-0 emission toward infrared dark sources (T_dust_<~20K), which do not contain identified outflow sources, may be related to other mechanisms producing low-velocity shocks (5-15km/s) for example, arising from cloud-cloud collisions, shocks triggered by expanding HII regions, global infall, or converging flows.2023A&A...679A.123Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/679/A123CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/473/1059 : Galactic clump properties complete sample (Urquhart+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/679/A123https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/679/A123http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/679/A123https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/679/A123https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/679/A123http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/679/A123GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/679/A123/table1 (List of observed sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/679/A123/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/679/A123/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/679/A123/table1?GETtext/xml+votable180.050000true3.6166764.479440.0055555555555555565/7377 7579 7654 6/1307 1340 1470 2973 3068 3271 3290 3649 13050-13051 14255 14267 14287 14299 14307 14309 14311 14314 14317 14333 14352-14353 14355 14358-14359 14409 14594 14614 14621-14622 14624-14625 14629-14630 14642 14644 14647 14655 14666 14670-14671 14689-14693 14696-14697 14704 15394 15430 15458 15479 15624 15629 15667 15676 15681 15683 21456 21458 21671 22855 23795 23969 23982 24189 24325 24378 24499 24507 24554 28890-28891 28912-28913 28916 28918-28919 29070 29090-29091 29094 29096-29097 29100-29101 29103 29112 29116 29118 29461 29505 29513 29529 29532-29533 29535 29556 30218-30219 30241 30244-30245 30256 30258-30260 30262-30263 30268-30269 30312-30313 30315 30328 30330 30341 30405 30416-30417 30419-30422 30425 30594-30595 30602 30604-30605 30607 30622 30644 30691-30692 30694-30695 30701 30714-30716 30719https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/679/A123?format=asciiRadiodefaultJ/A+A/679/A123/table1List of observed sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMoreindicates data in tables 3 and/or 4meta.ref.urlcharNameSource namemeta.id;meta.maincharprimaryRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainVsysSystemic velocitykm/sphys.velocfloatSiO[Y/N] SiO 1-0 detectionmeta.codecharn_SiO[abcde, ] Note (1)meta.notecharH2O[Y/N] H_2_O maser detectionmeta.codecharCH3OH[Y/N] CH_3_OH maser detectionmeta.codecharTypeSelected categorysrc.classcharATLASGALATLASGAL name (LLL.lll+BBB.bbb)meta.idcharClassATLASGAL classification (2)src.classcharJ/A+A/679/A123/table3Line parameters of SiO J=1-0recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqID numbermeta.idintNameSource namemeta.id;meta.maincharCompGaussian fitted componentmeta.code.multipintint(Tmbdv)Velocity integrated intensityK.km/sspect.line.intensityfloate_int(Tmbdv)Uncertainty on velocity integrated intensityK.km/sstat.errorfloatVpeakPeak velocitykm/sphys.veloc;stat.maxfloate_VpeakUncertainty on velocitykm/sstat.errorfloatFWHMFWHM line widthkm/sspect.line.widthfloate_FWHMUncertainty on FWHM line widthkm/sstat.error;phys.angSizefloatTmbPeak intensityKphot.fluxfloatrmsrmsmKstat.stdev;instr.det.noisefloatJ/A+A/679/A123/table4N(SiO), X(SiO), physical parameters of dust clumps, L(H_2_O), and L(CH_3_OH)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource Namemeta.id;meta.maincharN(SiO)? Column density of SiOcm**-2phys.columnDensitydoublenullablelog(N(H2))a? Column density of H_2_ (ATLASGAL)log(cm**-2)phys.columnDensityfloatnullablelog(N(H2))b? Column density of H_2_ (Hi-GAL PPMAP)log(cm**-2)phys.columnDensityfloatnullableX(SiO)? Abundance of SiOphys.abunddoublenullableDist? Source distancekpcpos.distancefloatnullableTdust? Dust temperatureKphys.temperaturefloatnullablelog(Lbol)? Bolometric luminositylog(solLum)phys.luminosityfloatnullablelog(Mclump)? Dust clump masslog(solMass)phys.massfloatnullableL(H2O)? H_2_O maser luminositysolLumphys.luminositydoublenullableL(CH3OH)? CH_3_OH maser luminositysolLumphys.luminositydoublenullable