J/ApJ/862/63ivo://CDS.VizieR/J/ApJ/862/63doi:10.26093/cds/vizier.18620063CDSCalahan J.K.Shirley Y.L.Svoboda B.E.Ivanov E.A.Schmid J.R.,Pulley A.Lautenbach J.Zawadzki N.Bullivant C.Cook C.W.Gray L.,Henrici A.Pascale M.Bosse C.Chance Q.Choi S.Dunn M.,Jaime-Frias R.Kearsley I.Kelledy J.Lewin C.Mahmood Q.Mckinley S.,Mitchell A.M.Robinson D.R.2025-05-22T20:11:29Z2023-09-29T16:22:13ZCDS support team

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

cds-question@unistra.frradio-astronomyinterstellar-mediumgalaxy-planesmilky-way-galaxyRecent Galactic plane surveys of dust continuum emission at long wavelengths have identified a population of dense, massive clumps with no evidence for ongoing star formation. These massive starless clump candidates are excellent sites to search for the initial phases of massive star formation before the feedback from massive star formation affects the clump. In this study, we search for the spectroscopic signature of inflowing gas toward starless clumps, some of which are massive enough to form a massive star. We observed 101 starless clump candidates identified in the Bolocam Galactic Plane Survey (BGPS) in HCO^+^J=1-0 using the 12m Arizona Radio Observatory telescope. We find a small blue excess of E=(N_blue_-N_red_)/N_total_=0.03 for the complete survey. We identified six clumps that are good candidates for inflow motion and used a radiative transfer model to calculate mass inflow rates that range from 500 to 2000M_{sun}_/Myr. If the observed line profiles are indeed due to large-scale inflow motions, then these clumps will typically double their mass on a freefall time. Our survey finds that massive BGPS starless clump candidates with inflow signatures in HCO^+^J=1-0 are rare throughout our Galaxy.2018ApJ...862...63Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/862/63CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJS/208/14 : BGPS. IX. Data release 2. (Ginsburg+, 2013)J/ApJ/777/157 : 90GHz obs. of high-mass star-forming regions (Hoq+, 2013)J/ApJS/209/2 : The BGPS. X. Dense molecular gas (Shirley+, 2013)J/A+A/568/A41 : ATLASGAL Compact Source Catalog: 280<l<60 (Urquhart+, 2014)J/ApJ/799/29 : BGPS. XII. DR2 distance catalog (Ellsworth-Bowers+, 2015)J/MNRAS/450/1926 : Infall motions in massive star-forming regions (He+, 2015)J/ApJ/822/59 : BGPS. XIV. Molecular cloud clumps GBT obs. (Svoboda+, 2016)J/ApJS/224/43 : Planck cold clumps & cores in 2nd quadrant (Zhang+, 2016)J/A+A/592/A21 : Are infrared dark clouds really quiescent? (Feng+, 2016)J/MNRAS/461/2288 : Infall motions in massive star-forming regions (He+, 2016)J/MNRAS/469/2163 : JCMT Plane Survey. first complete data release (Eden+, 2017)J/ApJ/846/144 : Virial analysis of the dense cores in Orion A (Kirk+, 2017)J/MNRAS/471/100 : Hi-GAL compact source catalog. -71.0<l<67.0 (Elia+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/862/63https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/862/63http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/862/63https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/862/63https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/862/63http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/862/63GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/862/63/table1 (Starless clump candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/862/63/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/862/63/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/862/63/table1?GETtext/xml+votable180.050000true272.3911667-20.78354440.0055555555555555565/7564 6/29090-29091 29100-29101 29103 29112-29113 29115 29118 29505 29508 29510-29511 29522 29529 29532-29533 29535 30216 30218-30219 30222 30241 30244-30245 30260 30262https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/862/63?format=asciiRadiodefaultJ/ApJ/862/63/table1Starless clump candidatese_Vlsr[0.003/0.3]? vlsr uncertaintykm/sstat.error;phys.veloc;pos.lsrfloatnullableDelv[-4.3/3.5]? The FWHM line width, {delta}vspect.line.widthfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBGPSv2BGPS v.2.0.1 catalog index number (Ginsburg+ 2013, J/ApJS/208/14)meta.id;meta.mainintRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainDist[1.17/11.8] Distance (1)kpcpos.distancefloatVlsr[-1.5/114.4]? Local Standard of Rest velocity for the HCO^+^ peakkm/sphys.veloc;pos.lsr;stat.maxfloatnullablee_Delv[0.005/0.3]? Delv uncertaintystat.errorfloatnullable