J/A+A/606/A100ivo://CDS.VizieR/J/A+A/606/A100doi:10.26093/cds/vizier.36060100CDSLada C.J.Lewis J.A.Lombardi M.Alves J.2020-10-30T10:33:40Z2018-02-19T15:43:39ZCDS support team

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

cds-question@unistra.frmolecular-cloudsyoung-stellar-objectsphotometryclassificationWe present new high resolution and dynamic range dust column density and temperature maps of the California Molecular Cloud derived from a combination of Planck and Herschel dust-emission maps, and 2MASS NIR dust-extinction maps. We used these data to determine the ratio of the 2.2{mu}m extinction coefficient to the 850{mu}m opacity and found the value to be close to that found in similar studies of the Orion B and Perseus clouds but higher than that characterizing the Orion A cloud, indicating that variations in the fundamental optical properties of dust may exist between local clouds. We show that over a wide range of extinction, the column density probability distribution function (pdf) of the cloud can be well described by a simple power law (i.e., PDF_N_{prop.to}A_K_^-n^) with an index (n=4.0+/-0.1) that represents a steeper decline with A_K_ than found (n~=3) in similar studies of the Orion and Perseus clouds. Using only the protostellar population of the cloud and our extinction maps we investigate the Schmidt relation, that is, the relation between the protostellar surface density, {Sigma}_*_, and extinction, A_K_, within the cloud. We show that {Sigma}_*_ is directly proportional to the ratio of the protostellar and cloud pdfs, i.e., PDF_*_(A_K_)/PDF_N_(A_K_). We use the cumulative distribution of protostars to infer the functional forms for both {Sigma}_*_ and PDF_*_. We find that {Sigma}_*_ is best described by two power-law functions. At extinctions A_K_<=2.5mag, {Sigma}_*_{prop.to}A_K_^{beta}^ with {beta}=3.3 while at higher extinctions {beta}=2.5, both values steeper than those (~=2) found in other local giant molecular clouds (GMCs). We find that PDF_*_ is a declining function of extinction also best described by two power-laws whose behavior mirrors that of {Sigma}_*_. Our observations suggest that variations both in the slope of the Schmidt relation and in the sizes of the protostellar populations between GMCs are largely driven by variations in the slope, n, of PDF_N_(A_K_). This confirms earlier studies suggesting that cloud structure plays a major role in setting the global star formation rates in GMCs2017A&A...606A.100Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/606/A100CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/587/A106 : Perseus dust optical depth & column density maps (Zari+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/606/A100https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/606/A100http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/606/A100https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/606/A100https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/606/A100http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/606/A100GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/606/A100/tablea1 (Young stellar objects in the California Molecular Cloud)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/606/A100/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/606/A100/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/606/A100/tablea1?GETtext/xml+votable180.050000true60.352291741.03027780.005555555555555556Cone search capability for table J/A+A/606/A100/list (List of fits datacubes)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/606/A100/list?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/606/A100/list?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/606/A100/list?GETtext/xml+votable180.050000true61.420602540.19958360.0055555555555555565/401 6/1231 1242-1243 1253 1261-1264 1266 1272 1274 1613-1614 1636https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/606/A100?format=asciidefaultJ/A+A/606/A100/tablea1Young stellar objects in the California Molecular CloudSimbadNameSimbad column added by the CDSmeta.idcharSeqSequential numbermeta.recordintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_Seq[*] Note on Seqmeta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainAKInfrared extinctionmagphys.absorptionfloate_AKrms uncertainty on AKmagstat.errorfloatIDB? Broekhoven-Fiene et al. (2014, Cat. J/ApJ/786/37) identification number, ([BMH2014] NNN in Simbad)meta.idintnullableClassBBroekhoven-Fiene et al. (2014, Cat. J/ApJ/786/37) classification (1)src.classcharIDH? Harvey et al. (2013, Cat. J/ApJ/764/133) identification number ([HFG2013] NN in Simbad)meta.idintnullableClassHHarvey et al. (2013, Cat. J/ApJ/764/133) classification (1)src.classcharClass[PDS] Classification (2)src.classcharJ/A+A/606/A100/listList of fits datacubesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGLONGalactic longitudedegpos.galactic.lonGLATGalactic latitudedegpos.galactic.latNxNumber of pixels along X-axismeta.numberintNyNumber of pixels along Y-axismeta.numberintNzNumber of planes (1)meta.numberintsizeSize of FITS fileKibytephys.size;meta.fitsintFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar_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)degpos.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)degpos.eq.decnullableindexed