J/ApJ/716/474ivo://CDS.VizieR/J/ApJ/716/474doi:10.26093/cds/vizier.17160474CDSWang J.Feigelson E.D.Townsley L.K.Broos P.S.Roman-Zuniga C.G.,Lada E.Garmire G.2017-07-06T06:26:25Z2012-06-18T08:41:10ZCDS support team

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

cds-question@unistra.frx-ray-sourcesastronomical-object-identificationopen-star-clusterspre-main-sequence-starsyoung-stellar-objectsWe present high spatial resolution Chandra X-ray images of the NGC 2237 young stellar cluster on the periphery of the Rosette Nebula. We detect 168 X-ray sources, 80% of which have stellar counterparts in USNO, Two Micron All Sky Survey, and deep FLAMINGOS images. These constitute the first census of the cluster members with 0.2<~M<~2M_{sun}_. Star locations in near-infrared color-magnitude diagrams indicate a cluster age around 2Myr with a visual extinction of 1<~A_V_<~3 at 1.4kpc, the distance of the Rosette Nebula's main cluster NGC 2244. We derive the K-band luminosity function and the X-ray luminosity function of the cluster, which indicate a population ~400-600 stars. The X-ray-selected sample shows a K-excess disk frequency of 13%. The young Class II counterparts are aligned in an arc ~3pc long suggestive of a triggered formation process induced by the O stars in NGC 2244. The diskless Class III sources are more dispersed. Several X-ray emitting stars are located inside the molecular cloud and around gaseous pillars projecting from the cloud. This X-ray view of young stars on the western side of the Rosette Nebula complements our earlier studies of the central cluster NGC 2244 and the embedded clusters on the eastern side of the Nebula. The large-scale distribution of the clusters and molecular material is consistent with a scenario in which the rich central NGC 2244 cluster formed first, and its expanding HII region triggered the formation of the now-unobscured satellite clusters Rosette Molecular Cloud (RMC) XA and NGC 2237. A large swept-up shell material around the HII region is now in a second phase of collect-and-collapse fragmentation, leading to the recent formation of subclusters.2010ApJ...716..474Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/716/474CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-2012)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)I/284 : The USNO-B1.0 Catalog (Monet+ 2003)J/ApJ/696/47 : Chandra study of Rosette complex. II. (Wang+, 2009)J/ApJ/675/464 : Chandra observations of NGC 2244 (Wang+, 2008)J/A+A/384/890 : BVRIHa photometry of NGC 2244 X-ray stars (Berghoefer+, 2002)J/ApJ/454/151 : OB Associations of the Northern Milky Way (Massey+ 1995)J/ApJ/428/693 : Rosette Nebula and Maddalena Cloud structures (Williams+ 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/716/474https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/716/474http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/716/474https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/716/474https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/716/474http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/716/474GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/716/474/catalog (Primary and Tentative Chandra catalog: X-ray properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/716/474/catalog?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/716/474/catalog?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/716/474/catalog?GETtext/xml+votable180.050000true97.57012195.08117890.0055555555555555566/222497.952274030004205e-20 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/716/474?format=asciiX-raydefaultJ/ApJ/716/474/catalogPrimary and Tentative Chandra catalog: X-ray propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/168] Running sequence number; sorted by RA (G1)meta.id;meta.mainintprimarySSimbad column added by the CDSmeta.idcharCXOUIAU designation (HHMMSS.ss+DDMMSS.s; J2000) (G1)meta.id;meta.maincharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainsigmaEstimated random component of position error (1)arcsecstat.errorfloatthetaOff-axis anglearcmininstr.offsetfloatCtEstimated net 0.5-8 keV countsctphot.count;em.X-rayfloate_CtPoisson-based 1{sigma} error in Ctctstat.errorfloatBtBackground 0.5-8 keV countsctphot.count;em.X-rayfloatChEstimated net 2-8 keV countsctphot.count;em.X-rayfloatPSFPSF fraction enclosed within extraction region (2)instr.det.psf;obs.field;arith.ratiofloatSigPhotometric significance (3)stat.fit.goodnessfloatl_logPBLimit flag on logPBmeta.code.errorcharlogPBLog probability of not-real source (4)stat.fit.goodnessfloatAnomSource anomalies (5)meta.codecharVar[a-c ] Variability characterization (6)meta.code;src.varcharExpEffective exposure time (7)kstime.duration;obs.exposurefloatEmedBackground-corrected median photon energy (0.5-8 keV)keVem.energyfloatSimbadSimbad column added by the CDSmeta.refcharJ/ApJ/716/474/table3X-ray spectroscopyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[2/168] Running sequence number (G1)meta.id;meta.mainintCXOUIAU designation (HHMMSS.ss+DDMMSS.s; J2000) (G1)meta.id;meta.maincharCtEstimated net 0.5-8 keV countsctphot.count;em.X-rayfloatSigPhotometric significance (1)stat.fit.goodnessfloatlogNHLog of hydrogen column density (2)log(cm**-2)phys.columnDensityfloatf_logNH[*] *: value was frozen in the fitmeta.codechare_logNH? Lower 90% confidence interval in logNH (3)log(cm**-2)stat.errorfloatnullableE_logNH? Upper 90% confidence interval in logNH (3)log(cm**-2)stat.error;stat.maxfloatnullablekTPlasma temperature (2)keVphys.temperaturefloatf_kT[*] *: value was frozen in the fitmeta.codechare_kT? Lower 90% confidence interval in kT (3)keVstat.error;phys.energyfloatnullableE_kT? Upper 90% confidence interval in kT (3)keVstat.error;stat.maxfloatnullablelogEMLog of emission measure; distance=1.4kpc (2)log(cm**-3)phys.emissMeasurefloate_logEM? Lower 90% confidence interval in logEM (3)log(cm**-3)stat.errorfloatnullableE_logEM? Upper 90% confidence interval in logEM (3)log(cm**-3)stat.error;stat.maxfloatnullablelogLs? Log of 0.5-2 keV luminosity (4)log(1e-07W)phys.luminosity;em.X-rayfloatnullablelogLhLog of 2-8 keV luminositylog(1e-07W)phys.luminosity;em.X-rayfloatlogLhcLog of absorption-corrected 2-8 keV luminositylog(1e-07W)phys.luminosity;em.X-rayfloatlogLtLog of 0.5-8 keV luminositylog(1e-07W)phys.luminosity;em.X-rayfloatlogLtc? Log of absorption-corrected 0.5-8 keV luminosity (4)log(1e-07W)phys.luminosity;em.X-rayfloatnullableJ/ApJ/716/474/table4Stellar counterpartsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/168] Running sequence number (G1) (1)meta.id;meta.mainintCXOUIAU designation (HHMMSS.ss+DDMMSS.s; J2000) (G1)meta.id;meta.maincharUSNOUSNO B1.0 identificationmeta.id.crosscharBmag? The B band magnitude (2)magphot.mag;em.opt.BfloatnullableRmag? The R band magnitude (2)magphot.mag;em.opt.RfloatnullableImag? The I band magnitude (2)magphot.mag;em.opt.Ifloatnullable2MASS2MASS identification (HHMMSSss+DDMMSSs; J2000)meta.id.crosscharFLAMFLAMINGOS identification (HHMMSS+DDMMSS) (G1)meta.id.crosscharJmag? The J band magnitude (2)magphot.mag;em.IR.JfloatnullableHmag? The H band magnitude (2)magphot.mag;em.IR.HfloatnullableKsmag? The K_S_ band magnitude (2)magphot.mag;em.IR.KfloatnullablePhFlg[A-U0c] Photometry flag (Qflg and Cfgl of Cat. II/246)meta.code.qualchar