J/ApJ/836/98ivo://CDS.VizieR/J/ApJ/836/98doi:10.26093/cds/vizier.18360098CDSJose J.Herczeg G.J.Samal M.R.Fang Q.Panwar N.2017-11-06T08:37:17Z2017-10-16T09:18:16ZCDS support team

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

cds-question@unistra.fropen-star-clustersyoung-stellar-objectsinfrared-photometryvisible-astronomyphotometryThe evolution of H II regions/supershells can trigger a new generation of stars/clusters at their peripheries, with environmental conditions that may affect the initial mass function, disk evolution, and star formation efficiency. In this paper we study the stellar content and star formation processes in the young cluster Stock 8, which itself is thought to be formed during the expansion of a supershell. We present deep optical photometry along with JHK and 3.6 and 4.5{mu}m photometry from UKIDSS and Spitzer-IRAC. We use multicolor criteria to identify the candidate young stellar objects in the region. Using evolutionary models, we obtain a median log(age) of ~6.5 (~3.0Myr) with an observed age spread of ~0.25dex for the cluster. Monte Carlo simulations of the population of Stock 8, based on estimates for the photometric uncertainty, differential reddening, binarity, and variability, indicate that these uncertainties introduce an age spread of ~0.15dex. The intrinsic age spread in the cluster is ~0.2dex. The fraction of young stellar objects surrounded by disks is ~35%. The K-band luminosity function of Stock 8 is similar to that of the Trapezium cluster. The initial mass function (IMF) of Stock 8 has a Salpeter-like slope at >0.5M_{Sun}_ and flattens and peaks at ~0.4M_{Sun}_, below which it declines into the substellar regime. Although Stock 8 is surrounded by several massive stars, there seems to be no severe environmental effect in the form of the IMF due to the proximity of massive stars around the cluster.2017ApJ...836...98Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/836/98CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVI/128 : Log of CGPS exposures (Taylor+, 2003-)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)II/316 : UKIDSS-DR6 Galactic Plane Survey (Lucas+ 2012)J/ApJ/540/1016 : K-band & NICMOS photom. of Trapezium Cluster (Luhman+, 2000)J/ApJ/573/366 : Infrared photometry of Trapezium cluster (Muench+, 2002)J/ApJ/593/1093 : IC 348 membership (Luhman+, 2003)J/MNRAS/379/289 : The outer Galaxy at 1420 and 408MHz. II. (Kerton+, 2007)J/ApJ/672/914 : HST photometry in NGC 346 (Hennekemper+, 2008)J/ApJ/686/1195 : IR photometry in the {gamma} Vel cluster (Hernandez+, 2008)J/MNRAS/384/1675 : BVRIc photometry of Stock 8 (Jose+, 2008)J/ApJ/688/377 : Low-mass objects in Upper Scorpius. II. (Slesnick+, 2008)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/MNRAS/392/1034 : IZJHKL' photometry of NGC 6611 (Oliveira+, 2009)J/A+A/539/A119 : Pismis 24 stars with X-ray emission (Fang+, 2012)J/ApJ/755/20 : YSOs population of Sh2-294 with Spitzer/IRAC (Samal+, 2012)J/ApJS/207/5 : YSOs in LDN 1641 with Hectochelle spectra (Fang+, 2013)J/A+A/558/A53 : MW global survey of star clusters. II. (Kharchenko+, 2013)J/ApJ/764/172 : UBVRI photometry of stars toward NGC 1931 (Pandey+, 2013)J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)J/A+A/569/A125 : Spiral structure of the Milky Way (Hou+, 2014)J/ApJ/787/107 : Spatial structure of young clusters. I. (Kuhn+, 2014)J/MNRAS/443/1614 : YSOs in BRC 5, 7 and 39 (Panwar+, 2014)J/A+A/566/A122 : JHK and IRAC photometry of Sh2-90 YSOs (Samal+, 2014)J/AJ/150/147 : Galactic HII regions. I. Stellar distances (Foster+, 2015)J/A+A/581/A66 : UV variability and accretion in NGC 2264 (Venuti+, 2015)J/ApJ/822/49 : Candidate YSOs in AFGL 333 (Jose+, 2016)J/MNRAS/459/880 : Open clusters in Auriga OB2 (Marco+, 2016)J/AJ/151/126 : Photom. of YSOs in 8 bright-rimmed clouds (Sharma+, 2016)J/A+A/585/A49 : VCNS II. The IR-excess-selected population (Zeidler+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/836/98https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/836/98http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/836/98https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/836/98https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/836/98http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/836/98GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/836/98/table2 (Photometric data of all point sources within 3' radius of Stock 8)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/836/98/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/836/98/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/836/98/table2?GETtext/xml+votable180.050000true81.971734.42080.0055555555555555566/12973.9193497546148093e-20 1.692669228152603e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/836/98?format=asciiOpticalInfrareddefaultJ/ApJ/836/98/table2Photometric data of all point sources within 3' radius of Stock 8recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainVmag[8.9/24.1]? SNIFS V band magnitudemagphot.mag;em.opt.VfloatnullableImag[8.6/22.3]? SNIFS I band magnitudemagphot.mag;em.opt.IfloatnullableJmag[8.3/20.1]? UKIDSS J band magnitudemagphot.mag;em.IR.JfloatnullableHmag[8.3/19.2]? UKIDSS H band magnitudemagphot.mag;em.IR.HfloatnullableKmag[8.3/18.4]? UKIDSS K band magnitudemagphot.mag;em.IR.Kfloatnullable3.6mag[8.2/17.2]? Spitzer/IRAC 3.6um band magnitudemagphot.mag;em.IR.3-4umfloatnullable4.5mag[8.2/17.1]? Spitzer/IRAC 4.5um band magnitudemagphot.mag;em.IR.4-8umfloatnullableClassClass ("I": 15 occurrences; "II": 146 occurrences or "III/field")src.classcharUKIDSSDisplay data from UKIDSS-DR6 Galactic Plane Survey (II/316) within 0.5"meta.ref.urlintnullablePapIDisplay data from Paper I (Jose+, 2008, J/MNRAS/384/1675) within 2"meta.ref.urlintnullable