J/ApJ/881/79ivo://CDS.VizieR/J/ApJ/881/79doi:10.26093/cds/vizier.18810079CDSMuzic+Muzic K.Scholz A.Pena Ramirez K.Jayawardhana R.,Schodel R.Geers V.C.Cieza L.A.Bayo A.2022-04-04T09:25:08Z2021-01-07T12:46:27ZCDS support team

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

cds-question@unistra.frh-ii-regionsopen-star-clustersstar-forming-regionsinfrared-photometryeffective-temperatureAs part of the ongoing effort to characterize the low-mass (sub)stellar population in a sample of massive young clusters, we have targeted the ~2Myr old cluster NGC2244. The distance to NGC2244 from Gaia DR2 parallaxes is 1.59kpc, with errors of 1% (statistical) and 11% (systematic). We used the Flamingos-2 near-infrared camera at the Gemini-South telescope for deep multi- band imaging of the central portion of the cluster (~2.4pc^2^). We determined membership in a statistical manner, through a comparison of the cluster's color-magnitude diagram to that of a control field. Masses and extinctions of the candidate members are then calculated with the help of evolutionary models, leading to the first initial mass function (IMF) of the cluster extending into the substellar regime, with the 90% completeness limit around 0.02M{sun}. The IMF is well represented by a broken power law (dN/dM{prop}M-{alpha}) with a break at ~0.4M{sun}. The slope on the high- mass side (0.4-7M{sun}) is {alpha}=2.12{+/-}0.08, close to the standard Salpeter slope. In the low-mass range (0.02-0.4M{sun}), we find a slope {alpha}=1.03{+/-}0.02, which is at the high end of the typical values obtained in nearby star-forming regions ({alpha}=0.5-1.0), but still in agreement within the uncertainties. Our results reveal no clear evidence for variations in the formation efficiency of brown dwarfs (BDs) and very low-mass stars due to the presence of OB stars, or for a change in stellar densities. Our finding rules out photoevaporation and fragmentation of infalling filaments as substantial pathways for BD formation.2019ApJ...881...79Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/881/79CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/ocl : Optically visible open clusters and Candidates (Dias+, 2002-2015)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/314 : UKIDSS-DR8 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/316 : UKIDSS-DR6 Galactic Plane Survey (Lucas+ 2012)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/ApJ/454/151 : OB Associations of the Northern Milky Way (Massey+ 1995)J/A+A/337/403 : Low-mass stars evolutionary models (Baraffe+ 1998)J/A+A/358/553 : uvby differential photometry of V578 Mon (Hensberge+, 2000)J/ApJ/602/816 : Chamaeleon I star-forming region census (Luhman, 2004)J/A+A/462/L17 : Dense cores in interstellar molecular clouds (Alves+, 2007)J/ApJ/660/1532 : Spitzer/IRAC-MIPS survey of NGC 2244 (Balog+, 2007)J/AJ/134/1368 : Proper motions in NGC 2244 and NGC 6530 (Chen+, 2007)J/ApJS/173/104 : Stellar population in Chamaeleon I (Luhman, 2007)J/A+A/492/277 : Analysis of Collinder 69 stars with VOSA (Bayo+, 2008)J/ApJ/675/1319 : Infrared photometry of NGC 3603 (Harayama+, 2008)J/ApJ/684/654 : Low-mass members of Chamaeleon I (Luhman+, 2008)J/ApJ/675/464 : Chandra observations of NGC 2244 (Wang+, 2008)J/ApJ/723/1019 : Galactic SFR and gas surface densities (Heiderman+, 2010)J/A+A/536/A63 : Collinder 69 very low mass stars & brown dwarfs (Bayo+,2011)J/ApJ/743/166 : X-ray and infra-red study of RCW 38 (Winston+, 2011)J/ApJ/748/14 : ONC population data from WFI observations (Da Rio+, 2012)J/ApJ/754/30 : VISTA IR photometry {sigma}Ori cluster (Pena Ramirez+, 2012)J/ApJ/744/6 : SONYC census of very low-mass objects NGC1333 (Scholz+,2012)J/MNRAS/434/806 : Pre-main-sequence isochrones. II. SFR (Bell+, 2013)J/A+A/556/A26 : Arches cluster: IR phot., extinction & masses (Habibi+,2013)J/A+A/558/A53 : Milky Way global survey star clusters II. (Kharchenko+,2013)J/MNRAS/431/3222 : UKIDSS GCS Upper Sco members (Lodieu, 2013)J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)J/ApJ/787/107 : Spatial structure of young stellar clusters. I. (Kuhn+,2014)J/ApJ/785/159 : SONYC census of substellar objects in Lupus 3 (Muzic+, 2014)J/ApJ/802/60 : Structure of young stellar clusters. II. (Kuhn+, 2015)J/AJ/150/40 : The Spitzer c2d survey of clouds. XII. Perseus (Young+,2015)J/MNRAS/461/1734 : HAWK-I JHK photometry of Orion Nebula Cloud (Drass+, 2016)J/ApJ/822/59 : BGPS. XIV. Molecular cloud clumps GBT obs. (Svoboda+, 2016)J/ApJ/836/34 : 24um excesses clusters & membership of NGC2244 (Meng+, 2017)J/ApJ/870/32 : Kinematics young star clusters & associations (Kuhn+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/881/79https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/881/79http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/881/79https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/881/79https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/881/79http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/881/79GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/881/79/table2 (Near-infrared photometry of sources in the NGC 2244 field covered by Flamingos-2 observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/881/79/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/881/79/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/881/79/table2?GETtext/xml+votable180.050000true97.95395834.972250.005555555555555556Cone search capability for table J/ApJ/881/79/table3 (Member candidates from Gaia DR2 and PS1, along with the best-fit parameters from the SED)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/881/79/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/881/79/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/881/79/table3?GETtext/xml+votable180.050000true97.960754.95813890.0055555555555555566/222498.305533028865447e-20 1.692669228152603e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/881/79?format=asciiInfrareddefaultJ/ApJ/881/79/table2Near-infrared photometry of sources in the NGC 2244 field covered by Flamingos-2 observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[0/792] Source IDmeta.id;meta.mainintprimaryRAJ2000[6] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[4] Degree of Declination (J2000)pos.eq.dec;meta.mainJmag[6.44/23] J-band magnitude (UKIDSS system)magphot.mag;em.IR.Jfloate_Jmag[0.02/0.31] J-band magnitude uncertaintymagstat.error;phot.magfloatHmag[6.43/22.3] H-band magnitude (UKIDSS system)magphot.mag;em.IR.Hfloate_Hmag[0.02/0.41] H-band magnitude uncertaintymagstat.error;phot.magfloatKmag[6.43/21.15] K-band magnitude (UKIDSS system)magphot.mag;em.IR.Kfloate_Kmag[0.01/0.4] K-band magnitude uncertaintymagstat.error;phot.magfloatCandIndicates that the source is a candidate member (link to table 3)meta.ref.urlcharJ/ApJ/881/79/table3Member candidates from Gaia DR2 and PS1, along with the best-fit parameters from the SEDAv[0/5]? Visual extinctionmagphys.absorptionfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[2/791] Source IDmeta.id;meta.mainintRAJ2000[6] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[4] Degree of Declination (J2000)pos.eq.dec;meta.mainTeff[2800/19500]? Effective temperature from SED fittingKphys.temperature.effectiveintnullablelogg[3.5/4.25]? log of surface gravitylog(cm.s**-2)phys.gravityfloatnullableMethSelection method (1)meta.notecharSimbadSimbad column added by the CDSmeta.ref.urlchar