J/other/RAA/20.1ivo://CDS.VizieR/J/other/RAA/20.115doi:10.26093/cds/vizier/dx/cakbbfCDSYang Y.Jiang Z.-B.Chen Z.-W.Zhang S.-B.Yu S.-L.Ao Y.-P.2026-02-10T20:07:45Z2021-10-01T13:47:39ZCDS support team

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

cds-question@unistra.frmolecular-cloudsinterstellar-mediumspectroscopyGravitational accretion accumulates the original mass. This process is crucial for us to understand the initial phases of star formation. Using the specific infall profiles in optically thick and thin lines, we searched the clumps with infall motion from the Milky Way Imaging Scroll Painting (MWISP) CO data in previous work. In this study, we selected 133 sources as a sub-sample for further research and identification. The excitation temperatures of these sources are between 7.0 and 38.5K, while the H_2_ column densities are between 10^21^ and 10^23^cm^-2^. We have observed optically thick lines HCO+(1-0) and HCN(1-0) using the DLH 13.7-m telescope, and found 56 sources with a blue profile and no red profile in these two lines, which are likely to have infall motions, with a detection rate of 42%. This suggests that using CO data to restrict the sample can effectively improve the infall detection rate. Among these confirmed infall sources are 43 associated with Class 0/I young stellar objects (YSOs), and 13 which are not. These 13 sources are probably associated with the sources in the earlier evolutionary stage. In comparison, the confirmed sources that are associated with Class 0/I YSOs have higher excitation temperatures and column densities, while the other sources are colder and have lower column densities. Most infall velocities of the sources that we confirmed are between 10^-1^ to 100km/s, which is consistent with previous studies.2020RAA....20..115Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/other/RAA/20.115CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/other/RAA/20.115https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/other/RAA/20.115http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/other/RAA/20.115https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/other/RAA/20.115https://vizier.iucaa.in/viz-bin/votable?-source=J/other/RAA/20.115http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/other/RAA/20.115GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/other/RAA/20.115/tableb1 (The derived clump parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/other/RAA/20.115/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/other/RAA/20.115/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/other/RAA/20.115/tableb1?GETtext/xml+votable180.050000true264.151667-24.1919440.0055555555555555566/1344 1937 3061 3157 3196 3627 3630 3645 3648 3748 12960 12968 14332 14347 14356 14410 14647 14665 14670 14675-14676 14678 14680 14683 14689 14704 15362-15363 15370 15668 15681-15684 22045 22243 23646 23770 23969 23982 29101 29103 29113-29115 29248 29462-29463 29466 29506 30219 30244 30256-30257 30315 30318 30328-30329 30341 30343 30352 30354-30356 30359 30366 30407 30417 30419 30421 30423 30427 30592 30602 30617 30644 30692-30694 30716 30719https://cdsarc.cds.unistra.fr/viz-bin/moc/J/other/RAA/20.115?format=asciidefaultJ/other/RAA/20.115/tableb1The derived clump parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource namemeta.id;meta.maincharn_Source[+] Note on Source (1)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainVLSRLSR velocitykm/sphys.veloc;pos.lsrfloatDistHeliocentric distancekpcpos.distancefloatTex(12CO)Excitation temperatureKphys.atmol.excitationfloatlog(N(H2))H_2_ column densitylog(cm**-2)phys.columnDensityfloatJ/other/RAA/20.115/tableb2The derived line parameters and profiles of samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource namemeta.id;meta.maincharVthickHCO+(1-0)? Peak velocity of HCO+(1-0)km/sspect.line.widthfloatnullablee_VthickHCO+(1-0)? rms uncertainty on VthickHCO+(1-0)km/sstat.errorfloatnullableVthickHCN(1-0)? Peak velocity of HCN(1-0)km/sspect.line.widthfloatnullablee_VthickHCN(1-0)? rms uncertainty on VthickHCN(1-0)km/sstat.errorfloatnullableVthinC18O(1-0)Peak velocity of C^18^O(1-0)km/sspect.line.widthfloate_VthinC18O(1-0)rms uncertainty on VthiniC18O(1-0)km/sstat.errorfloatdeltaVC18O(1-0)FWHM of C^18^O(1-0)spect.line.widthfloate_deltaVC18O(1-0)rms uncertainty on deltaVC18O(1-0)stat.errorfloatdeltaVHCO+(1-0)? Asymmetry of HCO+(1-0)spect.line.widthfloatnullablee_deltaVHCO+(1-0)? rms uncertainty on deltaVHCO+(1-0)stat.errorfloatnullabledeltaVHCN(1-0)? Asymmetry of HCN(1-0)spect.line.widthfloatnullablee_deltaVHCN(1-0)? rms uncertainty on deltaVHCN(1-0)stat.errorfloatnullableProfileProfile of HCO+(1-0) and HCN(1-0) (1)meta.notechar