J/AJ/162/153ivo://CDS.VizieR/J/AJ/162/153doi:10.26093/cds/vizier.51620153CDSNunez E.H.Povich M.S.Binder B.A.Townsley L.K.Broos P.S.2023-09-01T08:36:23Z2022-02-03T07:50:39ZCDS support team

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

cds-question@unistra.fra-starspre-main-sequence-starsyoung-stellar-objectsx-ray-sourcesstellar-massesextinctionWe use X-ray and infrared observations to study the properties of three classes of young stars in the Carina Nebula: intermediate-mass (2-5M{sun}) pre-main-sequence stars (IMPS; i.e., intermediate-mass T Tauri stars), late-B and A stars on the zero-age main sequence (AB), and lower-mass T Tauri stars (TTS). We divide our sources among these three subclassifications and further identify disk-bearing young stellar objects versus diskless sources with no detectable infrared (IR) excess emission using IR (1-8{mu}m) spectral energy distribution modeling. We then perform X-ray spectral fitting to determine the hydrogen-absorbing column density (N_H_), absorption-corrected X-ray luminosity (L_X_), and coronal plasma temperature (kT) for each source. We find that the X-ray spectra of both IMPS and TTS are characterized by similar kT and N_H_, and on average L_X_/L_bol_~4x10^-4^. IMPS are systematically more luminous in X-rays (by ~0.3dex) than all other subclassifications, with median L_X_=2.5x10^31^erg/s, while AB stars of similar masses have X-ray emission consistent with TTS companions. These lines of evidence converge on a magnetocoronal flaring source for IMPS X-ray emission, a scaled-up version of the TTS emission mechanism. IMPS therefore provide powerful probes of isochronal ages for the first ~10Myr in the evolution of a massive stellar population, because their intrinsic, coronal X-ray emission decays rapidly after they commence evolving along radiative tracks. We suggest that the most luminous (in both X-rays and IR) IMPS could be used to place empirical constraints on the location of the intermediate-mass stellar birth line.2021AJ....162..153Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/162/153CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/ApJS/194/2 : Chandra Carina Complex Project (CCCP) catalog (Broos+, 2011)J/ApJS/209/32 : Probable young stars in the MYStIX project (Broos+, 2013)J/ApJ/787/108 : Age estimates massive SFR stellar populations (Getman+, 2014)J/A+A/603/A81 : Trumpler 14 and 16 in the Carina nebula (Damiani+, 2017)J/A+A/622/A72 : Intermediate-mass T Tau stars spectra (Villebrun+, 2019)J/A+A/624/A137 : Stellar models and isochrones (Haemmerle+, 2019)J/A+A/648/A34 : KMOS O-type star detection in Tr 16-SE (Preibisch+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/162/153https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/162/153http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/162/153https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/162/153https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/162/153http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/162/153GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/162/153/table4 (X-ray and IR source properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/162/153/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/162/153/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/162/153/table4?GETtext/xml+votable180.050000true160.67162611-59.887440.0055555555555555566/37333 38016https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/162/153?format=asciiX-raydefaultJ/AJ/162/153/table4X-ray and IR source propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIAU source identifier; CXOGNC JHHMMSS.ss+DDMMSS.s (1)meta.id;meta.maincharMIRSpitzer MIR Vela-Carina source namemeta.id.crosscharRAJ2000[160/163] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-61/60] Declination (J2000)degpos.eq.dec;meta.mainClassTemperature-Mass classification (2)src.classcharYSOYSO source code; Section 2.1meta.codecharFrozenN_H_ frozen to mean IR AV code; Section 2.5meta.codecharDofC-Statistic/Degrees of Freedom (3)stat.fit.dofcharFullThe 0.5-8keV net countsctmeta.numberfloatVar[0/2] Variable code (4)meta.codeintArea[1.23/1137] Average aperture area (0.492arcsec^2^)phys.areadoubleTheta[0.22/10.2] Chandra off axis anglearcmininstr.offsetfloatSimbadSimbad column added by the CDSmeta.ref.urlcharMass[0.19/8.88] Mass from SEDsolMassphys.massfloate_Mass[0.005/3] Weighted uncertainty in MasssolMassstat.error;phys.massfloatNH[0.07/33] XSPEC hydrogen absorbing column1e+22cm**-2phys.abund.Xfloatb_NH[0.08/24.1]? 90% lower confidence on NH1e+22cm**-2stat.fit.paramfloatnullableB_NH[0.22/9.76]? 90% upper confidence on NH1e+22cm**-2stat.fit.paramfloatnullableAVSEDA_V_ from SED code; Section 3.1phys.absorptioncharAV[0/69259]? Mean on extinction AV (5)magphys.absorptiondoublenullableb_AV[-1.6/69259]? Weighted lower bound on AVmagphot.mag;stat.mindoublenullableB_AV[1.2/1.04e+6]? Weighted upper bound on AVmagphot.mag;stat.maxdoublenullable2TModSource fit with 2 temperature plasma model?meta.codecharkT[0.69/10.1] The plasma temperature (6)keVphys.temperaturefloatb_kT[0.29/5.35]? 90% lower confidence on kTkeVstat.fit.param;phys.energyfloatnullableB_kT[1.01/8.7]? 90% upper confidence on kTkeVstat.fit.param;phys.energyfloatnullableFxHc[6.9e-16/2.1e-12] Hard 2-8keV band absorption corrected flux ; in erg/s/cm^2^mW.m**-2phot.flux;em.X-ray.mediumdoubleFxTc[4.9e-15/3.1e-12] Total 0.5-8keV band absorption corrected flux ; in erg/s/cm^2^mW.m**-2phot.flux;em.X-ray.mediumdoublelogLxHc[29.7/33.2] log hard 2-8keV band absorption corrected luminosity; in erg/slog(1e-07W)phys.luminosityfloate_logLxHc[30/34] Uncertainty in logLxHc; in erg/slog(1e-07W)stat.errorfloatlogLb[-0.03/3.61] log bolometric luminosity from IR SEDlog(solLum)phys.luminosityfloate_logLb[0/1.6] Weighted uncertainty in logLblog(solLum)stat.errorfloat