J/ApJ/905/78ivo://CDS.VizieR/J/ApJ/905/78doi:10.26093/cds/vizier.19050078CDSYu H.Wang J.Tan J.C.2023-12-19T11:43:01Z2022-08-04T13:26:35ZCDS support team

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

cds-question@unistra.frx-ray-sourcesmolecular-cloudsinfrared-photometryyoung-stellar-objectsWe present a high spatial resolution Chandra X-ray study of two infrared dark clouds (IRDCs), G034.43+00.24 and G035.39-00.33, which are expected to be in the early phases of star cluster formation. We detect 112 and 209 valid X-ray point sources toward G034.43+00.24 and G035.39-00.33, respectively. We cross-match the X-ray point sources with the Two Micron All Sky Survey (2MASS), Galactic Legacy Infrared Midplane Survey Extraordinaire (GLIMPSE), and Wide-field Infrared Survey Explorer (WISE) catalogs and find 53% and 59% of the X-ray sources in G034.43+00.24 and in G035.39-00.33 have corresponding infrared counterparts, respectively. These sources are probable members of young massive clusters in formation, and using stellar isochrones we estimate that a population of 1-2Myr old, intermediate- to high-mass young stellar objects (YSOs) exist in both IRDCs. Two and 10 Class II counterparts to X-ray sources were identified in G034.43+00.24 and in G035.39-00.33, respectively, which are located in or near dark filaments. The X-ray luminosity function (XLF) of G035.39-00.33 implies that the total mass consists of up to ~1700M_{sun}_ of stars, using the XLF of the well-studied Orion Nebula Cluster as a calibrator. This corresponds to a star formation efficiency of at most 5%, indicating the system is still very much gas dominated and in an early stage of the star formation process. The population of G034.43+00.24 is less well determined due to the lower sensitivity of its observations.2020ApJ...905...78Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/905/78CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-2014)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)II/311 : WISE All-Sky Data Release (Cutri+ 2012)J/AJ/111/1964 : JHK photometry of NGC1333 (Lada+, 1996)J/ApJ/574/258 : X-ray-emitting young stars in Orion nebula (Feigelson+, 2002)J/ApJ/573/366 : Infrared photometry of Trapezium cluster (Muench+, 2002)J/ApJS/160/353 : Membership of the Orion nebula population (Getman+, 2005)J/ApJS/163/306 : Chandra study of the Cep B star-forming region (Getman+, 2006)J/ApJ/641/389 : Millimetric observations of IRDC cores (Rathborne+, 2006)J/ApJ/639/227 : MSX IRDC candidate catalog (Simon+, 2006)J/ApJ/653/1325 : Galactic distribution of infrared dark clouds (Simon+, 2006)J/ApJS/169/353 : Chandra sources in M17 (Broos+, 2007)J/A+A/468/353 : XMM-Newton Extended Survey of Taurus (Guedel+, 2007)J/ApJS/168/100 : X-ray study of star-forming region NGC 6357 (Wang+, 2007)J/ApJ/688/418 : X-ray flares in Orion young stars. I. (Getman+, 2008)J/ApJ/675/464 : Chandra observations of NGC 2244 (Wang+, 2008)J/A+A/505/405 : A catalogue of Spitzer dark clouds (Peretto+, 2009)J/ApJ/714/L285 : YSO candidates in M17 SWex (Povich+, 2010)J/ApJS/194/11 : Chandra study of Trumpler 15 in Carina (Wang+, 2011)J/AJ/144/101 : Multiwavelength data of IRAS 20050+2720 (Guenther+, 2012)J/ApJS/209/32 : Probable young stars in the MYStIX project (Broos+, 2013)J/ApJS/209/27 : MYStIX: the Chandra X-ray sources (Kuhn+, 2013)J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)J/A+A/606/A133 : IRDC G035.39-00.33 NH3 and CCS data cubes (Sokolov+, 2017)J/ApJS/235/43 : The 2nd MSFRs Omnibus X-ray Catalog (MOXC2) (Townsley+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/905/78https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/905/78http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/905/78https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/905/78https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/905/78http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/905/78GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/905/78/table1 (Log of Chandra observations of IRDCs G034.43+0.2 (G34.4) and G035.39-0.33 (G35.4))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/905/78/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/905/78/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/905/78/table1?GETtext/xml+votable180.050000true283.321.420.005555555555555556Cone search capability for table J/ApJ/905/78/g34sources (Basic source information of G034.43+0.2 (G34.4) (Table 2) and stellar counterparts (Table 7))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/905/78/g34sources?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/905/78/g34sources?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/905/78/g34sources?GETtext/xml+votable180.050000true283.192046941.422383060.005555555555555556Cone search capability for table J/ApJ/905/78/g35sources (Basic source information of G035.39-0.33 (G35.4) (Table 3) and stellar counterparts (Table 8))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/905/78/g35sources?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/905/78/g35sources?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/905/78/g35sources?GETtext/xml+votable180.050000true284.123842.077201110.0055555555555555566/30318-30319 303308.157980699529898e-21 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/905/78?format=asciiX-rayInfrareddefaultJ/ApJ/905/78/table1Log of Chandra observations of IRDCs G034.43+0.2 (G34.4) and G035.39-0.33 (G35.4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIRDC targetmeta.id;meta.maincharTargetOther name of the IRDC targetmeta.idcharObsID[14541/20103] Chandra observation identifiermeta.id;obs.param;obsintObsObservation date, start (UT)stime.start;obsnullableExp[17115/56074] Exposure timestime.duration;obs.exposureintRoll[146.9/239.21] Roll angledeginstr.offsetfloatRAJ2000[283.32/284.3] Right ascension aim point (J2000)degpos.eq.ra;meta.mainDEJ2000[1.4/2.13] Declination aim point (J2000)degpos.eq.dec;meta.mainJ/ApJ/905/78/g34sourcesBasic source information of G034.43+0.2 (G34.4) (Table 2) and stellar counterparts (Table 7)4.5mag[7.4/14.2]? IRAC 4.5um band apparent magnitudemagphot.mag;em.IR.4-8umfloatnullableBk-F[100/1997] Background counts extractedctinstr.backgroundfloatSimbadSimbad column added by the CDSmeta.ref.urlcharNoteAdditional notesmeta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintXspDisplay the X-ray spectroscopy (Table 5)meta.ref.urlcharSeq[1/209] X-ray catalog sequence numbermeta.idintCXOUIAU designation (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharprimaryRAJ2000[283.19/284.5] Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[1.2/2.4] Declination (J2000)degpos.eq.dec;meta.mainErr[0/1.5] Estimated random component of position errorarcsecstat.errorfloatTheta[0.3/11.8] Offaxis anglearcmininstr.offsetfloatNet-F[2/893] Estimated net counts extracted in total energy band (0.5-8keV)ctphot.count;em.X-rayfloatdelNet-F[1.5/31] Average of upper and lower errors on Net-Fctstat.errorfloatNet-H[-0.5/541] Estimated net counts extracted in hard band (2-8keV)ctphot.count;em.X-rayfloatfPSF[0.4/0.9] Fraction of PSF enclosed within extraction regioninstr.det.psffloatSig[1.1/29.1] Photometric significancestat.fit.goodness;photfloatl_logPBLimit flag on logPBmeta.code.errorcharlogPB[-5/-2.3] Log probability (1)stat.fit.goodnessfloatAnomSource anomalies (2)meta.codecharVarVariability characterization based on K-S statistics (3)meta.code;src.varcharExp[28.1/180] Effective Exposure timekstime.duration;obs.exposurefloatEmed[0.8/7] Background-corrected median photon energykeVem.energy;stat.median;em.X-rayfloatHR[-1/1] Hardness ratio, (H-S)/(H+S), with hard-band: 2-8keV and soft-band: 0.5-1.2keVmeta.notefloat2MASSNIR identification (HHMMSSss+DDMMSSs; J2000)meta.id.crosscharJmag[8.6/18.6]? J band apparent magnitudemagphot.mag;em.IR.JfloatnullableHmag[8.3/16.7]? H band apparent magnitudemagphot.mag;em.IR.HfloatnullableKmag[8.1/15.7]? K band apparent magnitudemagphot.mag;em.IR.KfloatnullableWISEWISE source name (JHHMMSS.ss+DDMMSS.s)meta.id.crosscharW1mag[7.5/13.3]? W1 band apparent magnitudemagphot.mag;em.IR.3-4umfloatnullableW2mag[7/13.7]? W2 band apparent magnitudemagphot.mag;em.IR.4-8umfloatnullableW3mag[3.5/11.3]? W3 band apparent magnitudemagphot.flux.density;em.IR.8-15umfloatnullableW4mag[-0.92/8.7]? W4 band apparent magnitudemagphot.flux.density;em.IR.15-30umfloatnullableGLIMPSEMIR identification (GLLL.llll+BB.bbbb)meta.id.crosschar3.6mag[7.4/15.6]? IRAC 3.6um band apparent magnitudemagphot.mag;em.IR.3-4umfloatnullable5.8mag[6.9/12.7]? IRAC 5.8um band apparent magnitudemagphot.flux.density;em.IR.4-8umfloatnullable8.0mag[5.8/12.1]? IRAC 8.0um band apparent magnitudemagphot.flux.density;em.IR.8-15umfloatnullableJ/ApJ/905/78/g35sourcesBasic source information of G035.39-0.33 (G35.4) (Table 3) and stellar counterparts (Table 8)SimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintXspDisplay the X-ray spectroscopy (Table 6)meta.ref.urlintnullableSeq[1/209] X-ray catalog sequence numbermeta.idintCXOUIAU designation (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharRAJ2000[283.19/284.5] Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[1.2/2.4] Declination (J2000)degpos.eq.dec;meta.mainErr[0/1.5] Estimated random component of position errorarcsecstat.errorfloatTheta[0.3/11.8] Offaxis anglearcmininstr.offsetfloatNet-F[2/893] Estimated net counts extracted in total energy band (0.5-8keV)ctphot.count;em.X-rayfloatdelNet-F[1.5/31] Average of upper and lower errors on Net-Fctstat.errorfloatBk-F[100/1997] Background counts extractedctinstr.backgroundfloatNet-H[-0.5/541] Estimated net counts extracted in hard band (2-8keV)ctphot.count;em.X-rayfloatfPSF[0.4/0.9] Fraction of PSF enclosed within extraction regioninstr.det.psffloatSig[1.1/29.1] Photometric significancestat.fit.goodness;photfloatl_logPBLimit flag on logPBmeta.code.errorcharlogPB[-5/-2.3] Log probability (1)stat.fit.goodnessfloatAnomSource anomalies (2)meta.codecharVarVariability characterization based on K-S statistics (3)meta.code;src.varcharExp[28.1/180] Effective Exposure timekstime.duration;obs.exposurefloatEmed[0.8/7] Background-corrected median photon energykeVem.energy;stat.median;em.X-rayfloatHR[-1/1] Hardness ratio, (H-S)/(H+S), with hard-band: 2-8keV and soft-band: 0.5-1.2keVmeta.notefloat2MASSNIR identification (HHMMSSss+DDMMSSs; J2000)meta.id.crosscharJmag[8.6/18.6]? J band apparent magnitudemagphot.mag;em.IR.JfloatnullableHmag[8.3/16.7]? H band apparent magnitudemagphot.mag;em.IR.HfloatnullableKmag[8.1/15.7]? K band apparent magnitudemagphot.mag;em.IR.KfloatnullableWISEWISE source name (JHHMMSS.ss+DDMMSS.s)meta.id.crosscharW1mag[7.5/13.3]? W1 band apparent magnitudemagphot.mag;em.IR.3-4umfloatnullableW2mag[7/13.7]? W2 band apparent magnitudemagphot.mag;em.IR.4-8umfloatnullableW3mag[3.5/11.3]? W3 band apparent magnitudemagphot.flux.density;em.IR.8-15umfloatnullableW4mag[-0.92/8.7]? W4 band apparent magnitudemagphot.flux.density;em.IR.15-30umfloatnullableGLIMPSEMIR identification (GLLL.llll+BB.bbbb)meta.id.crosschar3.6mag[7.4/15.6]? IRAC 3.6um band apparent magnitudemagphot.mag;em.IR.3-4umfloatnullable4.5mag[7.4/14.2]? IRAC 4.5um band apparent magnitudemagphot.mag;em.IR.4-8umfloatnullable5.8mag[6.9/12.7]? IRAC 5.8um band apparent magnitudemagphot.flux.density;em.IR.4-8umfloatnullable8.0mag[5.8/12.1]? IRAC 8.0um band apparent magnitudemagphot.flux.density;em.IR.8-15umfloatnullableNoteAdditional notesmeta.notecharJ/ApJ/905/78/table5X-ray spectroscopy for selected sources of G34.4: thermal plasma fitsCXOUIAU designation (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/209] X-ray source numbermeta.idintNetCts[10/99] Estimated net counts extracted in total bandctphot.count;em.X-rayfloatSig[2.2/9.1] Photometric significancestat.fit.goodness;photfloatlogNH[20.2/23.5] Estimated column densitylog(cm**-2)phys.columnDensityfloatE_logNH[0.1/2.6]? Upper uncertainty in logNHlog(cm**-2)stat.error;stat.maxfloatnullablee_logNH[0.1/0.9]? Lower uncertainty in logNHlog(cm**-2)stat.errorfloatnullablekT[0.2/10] Estimated plasma energykeVphys.temperaturefloate_kT[0.2/5.5]? Lower uncertainty in kTkeVstat.error;phys.energyfloatnullableE_kT[0.5/10]? Upper uncertainty in kTkeVstat.error;stat.maxfloatnullablelogEM[51.7/57.8] Estimated plasma emission measurelog(cm**-3)phys.emissMeasurefloate_logEM[0.1/9.4] Lower uncertainty in logEMlog(cm**-3)stat.errorfloatE_logEM[0.1/3.3]? Upper uncertainty in logEMlog(cm**-3)stat.error;stat.maxfloatnullablelogLs[25.2/31.3] Observed soft band (0.5-1.2keV) X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatlogLh[27.8/32.2] Observed hard band (2-7keV) X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatlogLhc[27.9/32.7] Absorption corrected hard band X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatlogLt[29.7/32.2] Observed total band X-ray luminosity in erg/s unitslog(1e-07W)phys.luminosity;em.X-rayfloatlogLtc[30/35.7] Absorption corrected total band X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatNoteAdditional notesmeta.notecharJ/ApJ/905/78/table6X-ray spectroscopy for selected Sources of G35.4: thermal plasma fitse_kT[0.2/5.5]? Lower uncertainty in kTkeVstat.error;phys.energyfloatnullableE_kT[0.5/10]? Upper uncertainty in kTkeVstat.error;stat.maxfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/209] X-ray source numbermeta.idintCXOUIAU designation (HHMMSS.ss+DDMMSS.s; J2000)meta.id;meta.maincharNetCts[10/99] Estimated net counts extracted in total bandctphot.count;em.X-rayfloatSig[2.2/9.1] Photometric significancestat.fit.goodness;photfloatlogNH[20.2/23.5] Estimated column densitylog(cm**-2)phys.columnDensityfloatE_logNH[0.1/2.6]? Upper uncertainty in logNHlog(cm**-2)stat.error;stat.maxfloatnullablee_logNH[0.1/0.9]? Lower uncertainty in logNHlog(cm**-2)stat.errorfloatnullablekT[0.2/10] Estimated plasma energykeVphys.temperaturefloatlogEM[51.7/57.8] Estimated plasma emission measurelog(cm**-3)phys.emissMeasurefloate_logEM[0.1/9.4] Lower uncertainty in logEMlog(cm**-3)stat.errorfloatE_logEM[0.1/3.3]? Upper uncertainty in logEMlog(cm**-3)stat.error;stat.maxfloatnullablelogLs[25.2/31.3] Observed soft band (0.5-1.2keV) X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatlogLh[27.8/32.2] Observed hard band (2-7keV) X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatlogLhc[27.9/32.7] Absorption corrected hard band X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatlogLt[29.7/32.2] Observed total band X-ray luminosity in erg/s unitslog(1e-07W)phys.luminosity;em.X-rayfloatlogLtc[30/35.7] Absorption corrected total band X-ray luminosity, in erg/slog(1e-07W)phys.luminosity;em.X-rayfloatNoteAdditional notesmeta.notechar