J/ApJS/123/233ivo://CDS.VizieR/J/ApJS/123/233doi:10.26093/cds/vizier.21230233CDSLee C.W.Myers P.C.2021-08-10T09:25:29Z2000-07-06T16:10:10ZCDS support team

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

cds-question@unistra.frcatalogsvisible-astronomyinterstellar-mediumpre-main-sequence-starsWe present a new catalog of 406 dense cores optically selected by using the STScI Digitized Sky Survey (DSS). In this catalog 306 cores have neither an embedded young stellar object (EYSO) nor a pre-main-sequence (PMS) star, 94 cores have EYSOs (one core has both an EYSO and a PMS star), and six cores have PMS stars only. Our sample of dense cores in the catalog is fairly complete within a category of northern Lynds class 5 and 6 clouds and southern Hartley et al. class A clouds, providing a database useful for the systematic study of dense cores. Most of the cores listed in the catalog have diameters between 0.05 and 0.36 pc with a mean of ~0.24pc. The sizes (~0.33pc in the mean) of cores with EYSOs are found to be usually larger than the sizes (~0.22pc in the mean) of starless cores. The typical mean gas density of the cores is ~7x10^3^cm^-3^. Most of the cores are more likely elongated than spherical (mean aspect ratio: ~2.4). The ratio of the number of cores with EYSOs to the number of starless cores for our sample is about 0.3, suggesting that the typical lifetime of starless cores is 0.3-1.6Myr, about 3 times longer than the duration of the class 0 and class I phases. This lifetime is shorter than expected from models of ambipolar diffusion, by factors of 2-44.1999ApJS..123..233Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/123/233CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/123/233https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/123/233http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/123/233https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/123/233https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/123/233http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/123/233GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/123/233/table1 (Searched reference regions)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/123/233/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/123/233/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/123/233/table1?GETtext/xml+votable180.050000true10.68229262.0168810.005555555555555556Cone search capability for table J/ApJS/123/233/table2 (Optically Selected Cores)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/123/233/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/123/233/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/123/233/table2?GETtext/xml+votable180.050000true0.84759967.3130330.005555555555555556Cone search capability for table J/ApJS/123/233/table3 (IRAS Point Sources and PMS Stars Associated with Optically Selected Cores)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/123/233/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/123/233/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/123/233/table3?GETtext/xml+votable180.050000true43.99282969.2454730.0055555555555555565/263 3869 6/859 1031 1037 1039 1048 1050 1061 1063 1067 1068 1074 1075 1080 1114 1115 1117 1126 1129 1136 1168 1170 1290 1542 1825 1935 1937 1959 1968 3038 3331 3755 3849 3898 12964 13981 13997 14002 14052 14199 14270 14317 14319 14330 14333 14347 14350 14351 14369 14371 14372 14654 14663 14686 14707 14708 14710 15379 15408 15411 15426 15433 15541 15543 15556 15582 15588 15589 15590 15630 15633 15643 15649 15816 15851 15857 15964 15965 16129 16131 16196 16197 16198 21458 22205 22829 23549 23560 23561 23704 23739 23970 24300 24305 24515 28783 28962 29101 29112 29189 29191 29211 29214 29245 29247 29347 29350 29354 29362 29366 29367 29373 29374 29375 29377 29510 29511 29517 29528 29532 29551 29554 29560 29561 29562 29566 29597 29646 29653 29657 29661 29668 29673 29682 29683 29884 30219 30228 30229 30234 30249 30272 30344 30346 30349 30355 30519 30574 30575 30609 30621 30623 30664 30666 30670 30733 30741 30743 30748 30792 30798 30820 30821 31257 31263 31285 32011 32068 32092 36953 36956 36957 36958 37126 37241 37747 37817 37819 37820 38531 38534 39132 39134 39185 39361 39370 39396 41099 41123 41126 41127 41132 41133 41134 41515 41518 41559 41644 41822 41838 41870 42228 42233 42317 42339 42343 42400 42478 42568 42573 42586 42595 42597 42598 42610 42611 42614 42704 42705 42714 42727 42736 42737 42738 42760 42777 42784 42970 42981 42983 42992 42993 43010 43013 479061.9864425968556103e-21 1.6553710307751707e-20https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/123/233?format=asciiOpticaldefaultJ/ApJS/123/233/table1Searched reference regionsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion designationmeta.id;meta.maincharn_Region[*] for region of larger size (1)meta.notecharRAB1950Right ascension (B1950)pos.eq.ra;meta.mainDEB1950Declination (B1950)pos.eq.dec;meta.mainRefReference (2)meta.ref;pos.framecharNcoreNumber of cores selected in each reference regionmeta.numberint_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.decnullableindexedJ/ApJS/123/233/table2Optically Selected CoresrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[LM99]Sequential number (1)meta.idintSourceSource namemeta.id;meta.maincharRAB1950Right ascension (B1950)pos.eq.ra;meta.mainDEB1950Declination (B1950)pos.eq.dec;meta.mainSmaj? Size of major axis of FWHM of selected coresarcminphys.angSizefloatnullableSmin? Size of minor axis of FWHM of selected coresarcminphys.angSizefloatnullableDiamEquivalent diameter (2)arcminphys.angSizefloatPA[-90/90]? Position angle of the core (- clockwise and + counterclockwise with respect to equatorial north)degpos.posAngintnullableEYSO[NYPM/* ] Core structure (3)src.class.structcharDC[1,4] Darkness contrast (4)meta.noteintClassLynds opacity class and Hartley A classmeta.code.classcharDist? Distance to the corespcpos.distanceintnullabler_Dist? Reference for core distances in refs.dat filemeta.ref;pos.frameintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.decnullableindexedJ/ApJS/123/233/table3IRAS Point Sources and PMS Stars Associated with Optically Selected CoresrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource namemeta.id;meta.maincharIRASIRAS or PMS Namemeta.idcharn_IRAS[1,4]? Note on IRAS (1)meta.noteintnullableRAB1950Right ascension (B1950)pos.eq.ra;meta.mainDEB1950Declination (B1950)pos.eq.dec;meta.mainF12um? 12{mu}m flux densityJyphot.flux.density;em.IR.8-15umfloatnullablef_F12um[L] for lower limitmeta.codecharF25um? 25{mu}m flux densityJyphot.flux.density;em.IR.15-30umfloatnullablef_F25um[L] for lower limitmeta.codecharF60um? 60{mu}m flux densityJyphot.flux.density;em.IR.30-60umfloatnullablef_F60um[L] for lower limitmeta.codecharF100um? 100{mu}m flux densityJyphot.flux.density;em.IR.60-100umfloatnullablef_F100um[L] for lower limitmeta.codecharLink1IRAS data for this sourcemeta.ref.urlchar_RA.icrsRight ascension (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.ranullableindexed_DE.icrsDeclination (ICRS) (computed by VizieR, not part of the original data. The format may include more digits than the original data because of internal accuracy requirements in VizieR and across other CDS services)pos.eq.decnullableindexedJ/ApJS/123/233/refsReferences to table2RefNoReference numbermeta.ref;pos.frameintBibCodeBibCodemeta.bib.bibcodecharAutAuthors' namesmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObjectObjects consideredmeta.id;meta.maincharnullable