J/A+A/475/959ivo://CDS.VizieR/J/A+A/475/959doi:10.26093/cds/vizier.34750959CDSForbrich J.Preibisch T.2017-12-12T14:44:59Z2008-05-01T10:47:16ZCDS support team

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

cds-question@unistra.frpre-main-sequence-starsx-ray-sourcesTo study the X-ray properties of young stellar objects (YSOs), we analyze an exceptionally sensitive Chandra dataset of the Coronet cluster in the CrA star-forming region, achieving a limiting luminosity of L_X,min_~5x10^26^erg/s for lightly absorbed sources. This dataset represents one of the most sensitive X-ray observations ever obtained of a star-forming region. The X-ray data are used to investigate the membership status of tentative members of the region, to derive plasma temperatures and X-ray luminosities of the YSOs, and to investigate variability on the timescale of several years. 46 of the 92 X-ray sources in the merged Chandra image can be identified with optical or near/mid-infrared counterparts. X-ray emission is detected from all of the previously known optically visible late-type (spectral types G to M) stellar cluster members, from five of the eight brown dwarf candidates, and from nine embedded objects ("protostars") with class 0, class I, or flat-spectrum spectral-energy distributions (SEDs) in the field of view. While the Herbig Ae/Be stars TY CrA and R CrA, a close companion of the B9e star HD 176386, and the F0e star T CrA are detected, no X-ray emission is found from any of the Herbig-Haro (HH) objects or the protostellar cores without infrared source. We find indications for diffuse X-ray emission near R CrA/IRS 7.2007A&A...475..959Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/475/959CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/475/959https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/475/959http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/475/959https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/475/959https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/475/959http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/475/959GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/475/959/tablea1 (Complete source list with parameters determined by acis_extract for the energy range of 0.5-8keV)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/475/959/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/475/959/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/475/959/tablea1?GETtext/xml+votable180.050000true285.2690833-37.02488890.0055555555555555566/47742 47825 47828https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/475/959?format=asciiX-raydefaultJ/A+A/475/959/tablea1Complete source list with parameters determined by acis_extract for the energy range of 0.5-8keVrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCXOJCXOJ designation (HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharprimaryn_CXOJ[*] *: manually added sourcemeta.notecharCountsNet (background-subtracted) countsctphot.count;em.X-rayfloatE_CountsError on Counts (upper limit)ctstat.error;stat.maxfloate_CountsError on Counts (lower limit)ctstat.error;phot.countfloatMedEMedian photon energykeVem.energyfloatSigniSource significance (photometric S/N ratio)stat.likelihood;obsfloatHR1Hardness ratio HR1 (1)phot.flux;arith.ratiofloatE_HR1Error on HR1 (upper limit)stat.error;stat.maxfloate_HR1Error on HR1 (lower limit)stat.errorfloatHR2Hardness ratio HR2 (1)phot.flux;arith.ratiofloatE_HR2Error on HR2 (upper limit)stat.error;stat.maxfloate_HR2Error on HR2 (lower limit)stat.errorfloatHR3Hardness ratio HR3 (1)phot.flux;arith.ratiofloatE_HR3? Error on HR3 (upper limit)stat.error;stat.maxfloatnullablee_HR3Error on HR3 (lower limit)stat.errorfloatXSimbad column added by the CDSmeta.ref.urlcharFlux1axis_extract estimate of the observed flux, which is done channel-wisecount.cm**-2.s**-1phot.flux;em.X-raydoubleFlux2axis_extract estimate of the observed flux, which is done using an averaged valuecount.cm**-2.s**-1phot.flux;em.X-raydoubleRelExpRatio of the summed exposure map values at the source position relative to the maximum value (2)stat.fit.omcfloatNobsNumber of observations in which a source was detected (3)meta.numberint_RAPosition (derived from CXO name (right ascension part)degpos.eq.ra;meta.main_DEPosition (derived from CXO name (declination part)degpos.eq.dec;meta.mainJ/A+A/475/959/tablea2X-ray spectral fitting results for one- and two-temperature modelsDOFDegree of freedomstat.fit.dofintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCXOJCXOJ designation (HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_CXOJ[ab] Note on CXOJ (1)meta.notecharNHHydrogen column density1e+22cm**-2phys.columnDensityfloatE_NHError on NH (upper limit)1e+22cm**-2stat.error;stat.maxfloate_NH? Error on NH (lower limit)1e+22cm**-2stat.errorfloatnullablel_T1Limit flag on T1meta.code.errorcharT1Plasma temperature T1MKphys.temperaturefloatE_T1? Error on T1 (upper limit)MKstat.error;stat.maxfloatnullablee_T1? Error on T1 (lower limit)MKstat.errorfloatnullableT2? Second plasma temperature for two-temperature modelMKphys.temperaturefloatnullableE_T2? Error on T2 (upper limit)MKstat.error;stat.maxfloatnullablee_T2? Error on T2 (lower limit)MKstat.errorfloatnullableNorm1Normalization factor from XSPEC (2)stat.fit.paramdoubleE_Norm1Error on Norm1 (upper limit)stat.error;stat.maxdoublee_Norm1Error on Norm1 (lower limit)stat.errordoubleNorm2? Second normalization factor from XSPEC for two-temperature model (2)stat.fit.paramdoublenullablee_Norm2? rms uncertainty on Norm2stat.errordoublenullableLXExtinction-corrected (unabsorbed) X-ray luminosity integrated over the 0.2-8keV band) derived from the model parameters1e-07Wphys.luminosity;em.X-raydoublechi2Goodness-of-fit measure chi^2^_red_ valuestat.fit.chi2floatJ/A+A/475/959/table2Identification of Chandra X-ray sources with optical or infrared counterparts in the CrA star-forming regionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintCXOJCXOJ designation (HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharn_CXOJ[a] Note for IRS 5a/b CXOJ (1)meta.notecharOpt[y/n] Counterparts to the X-ray source in the optical DSS images ? (2)meta.codecharNIR[y/n] Counterparts to the X-ray source in the infrared 2MASS images ? (2)meta.codecharMIR[y/n] Counterparts to the X-ray source in the infrared Spitzer images ? (2)meta.codecharSEDSED class derived from the Spitzer photometrymeta.code.classcharNameName(s) (3)meta.idcharSpTypeMK spectral type(s)src.spTypecharLbol? Stellar bolometric luminositysolLumphys.luminosityfloatnullableu_Lbol[?] Uncertain Lbol (1)meta.code.errorchar