J/AJ/150/145ivo://CDS.VizieR/J/AJ/150/145doi:10.26093/cds/vizier.51500145CDSWolk S.J.Gunther H.M.Poppenhaeger K.Cody A.M.Rebull L.M.,Forbrich J.Gutermuth R.A.Hillenbrand L.A.Plavchan P.Stauffer J.R.,Covey K.R.Song I.2018-01-12T11:17:18Z2016-05-24T16:17:14ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsvariable-starsinfrared-photometryinfrared-sourcespre-main-sequence-starsx-ray-sourcesWe present an IR-monitoring survey with the Spitzer Space Telescope of the star-forming region GGD 12-15. More than 1000 objects were monitored, including about 350 objects within the central 5', which is found to be especially dense in cluster members. The monitoring took place over 38 days and is part of the Young Stellar Object VARiability project. The region was also the subject of a contemporaneous 67 ks Chandra observation. The field includes 119 previously identified pre-main sequence star candidates. X-rays are detected from 164 objects, 90 of which are identified with cluster members. Overall, we find that about half the objects in the central 5' are young stellar objects (YSOs) based on a combination of their spectral energy distribution, IR variability, and X-ray emission. Most of the stars with IR excess relative to a photosphere show large amplitude (>0.1 mag) mid-infrared (mid-IR) variability. There are 39 periodic sources, and all but one is found to be a cluster member. Almost half of the periodic sources do not show IR excesses. Overall, more than 85% of the Class I, flat spectrum, and Class II sources are found to vary. The amplitude of the variability is larger in more embedded YSOs. Most of the Class I/II objects exhibit redder colors in a fainter state, which is compatible with time-variable extinction. A few become bluer when fainter, which can be explained with significant changes in the structure of the inner disk. A search for changes in the IR due to X-ray events is carried out, but the low number of flares prevented an analysis of the direct impact of X-ray flares on the IR light curves. However, we find that X-ray detected Class II sources have longer timescales for change in the MIR than a similar set of non-X-ray detected Class IIs.2015AJ....150..145Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/150/145CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/150/118 : YSOVAR photometry in IRAS 20050+2720 (Poppenhaeger+, 2015)J/AJ/148/122 : YSOVAR: infrared photometry in Lynds 1688 (Gunther+, 2014)J/AJ/145/66 : Spitzer light curves of YSOs in IC 348 (Flaherty+, 2013)J/AJ/144/101 : Multiwavelength data of IRAS 20050+2720 SFR (Guenther+, 2012)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/AJ/135/693 : X-ray and IR sources in RCW 108 (Wolk+, 2008)J/AJ/132/1100 : X-ray and IR sources in RCW 38 (Wolk+, 2006)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/150/145https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/150/145http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/150/145https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/150/145https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/150/145http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/150/145GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/150/145/table1 (Source designations, flux densities and light curve properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/150/145/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/150/145/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/150/145/table1?GETtext/xml+votable180.050000true92.6036492-6.3365798240.005555555555555556Cone search capability for table J/AJ/150/145/table2 (Properties of X-ray sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/150/145/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/150/145/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/150/145/table2?GETtext/xml+votable180.050000true92.62519988-6.323635090.0055555555555555566/21456 214586.772611666688002e-21 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/150/145?format=asciiInfraredX-raydefaultJ/AJ/150/145/table3Properties of periodic sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSSTYSVIAU designation within the Spitzer Space Telescope (SST) Young Stellar Object VARiability (YSOVAR) program (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharXrX-ray source? (yes or no)meta.codecharMmStandard set or cluster member? (yes or no)stat.errorcharPer[0.14/14] Perioddtime.periodfloatPower[12.4/35.4] Periodogram peak powerstat.fit.paramfloatl_FAP[<] Upper limit flag on FAPmeta.code.errorcharFAP[0.001/0.03] False Alarm probabilitystat.fit.goodnessfloatCl1Infrared class from Gutermuth et al. 2009 (cat. J/ApJS/184/18) (II, III, or Transition)src.classcharCl2Infrared class according to Spectral Energy Distribution (SED) slope (F, I, II, or III) (G1)src.classcharJ/AJ/150/145/table1Source designations, flux densities and light curve propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSSTYSVIAU designation within the Spitzer Space Telescope (SST) Young Stellar Object VARiability (YSOVAR) program (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharprimaryAllmeta.numberintnullablePSimbad column added by the CDSmeta.ref.urlcharXmeta.ref.urlcharRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainNboth[0/79] Number of datapoints in light curve with both [3.6] and [4.5] datameta.numberint<[3.6]>[7.4/16.7]? Mean 3.6{mu}m band light curve magnitudemagphot.mag;em.IR.3-4umfloatnullables_<[3.6]>[0.01/0.61]? Width of 3.6{mu}m band distribution from 10% to 90%magstat.fit.paramfloatnullableo_<[3.6]>[0/80] Number of datapoints in [3.6] band light curvemeta.numberint<[4.5]>[6.6/16.4]? Mean 4.5{mu}m band light curve magnitudemagphot.mag;em.IR.4-8umfloatnullables_<[4.5]>[0.01/1.4]? Width of 4.5{mu}m band distribution from 10% to 90%magstat.fit.paramfloatnullableo_<[4.5]>[0/80] Number of datapoints in [4.5] band light curvemeta.numberintmed3.6[7.4/16.7]? Median 3.6{mu}m band light curve magnitudemagstat.fit.paramfloatnullablemed4.5[6.6/16.4]? Median 4.5{mu}m band light curve magnitudemagstat.fit.paramfloatnullableMAD3.6[0/0.19]? Median Absolute Deviation of 3.6{mu}m band light curvemagstat.stdevfloatnullableMAD4.5[0/0.27]? Median absolute deviation of 4.5{mu}m band light curvemagstat.stdevfloatnullablechi3.6[0.1/326.2]? Reduced {chi}^2^ to mean of 3.6{mu}m bandmagstat.fit.chi2floatnullablechi4.5[0.05/568.3]? Reduced {chi}^2^ to mean of 4.5{mu}m bandmagstat.fit.chi2floatnullablet3.6[0.2/10.6]? Decay time of AutoCorrelation Function (ACF) in 3.6{mu}m banddstat.fit.paramfloatnullablet4.5[0.2/10.2]? Decay time of ACF in 4.5{mu}m banddstat.fit.paramfloatnullableCMD[-0.4/16.2]? Angle of best-fit line in [3.6], [3.6]-[4.5] color-Magnitude Diagram (CMD)radstat.fit.paramdoublenullablee_CMD[0/0.54]? Uncertainty in CMDradstat.errorfloatnullableLength[-1.57/1.57]? Length of best-fit line in [3.6], [3.6]-[4.5] CMDmagstat.fit.paramfloatnullableStet[0/1.6]? Stetson index for 3.6 and 4.5{mu}m two-band light curvemeta.code;spect.indexfloatnullableJmag[8.7/17.6]? 2MASS J band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag[0/0.3]? Observational uncertainty in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag[7.7/16.8]? 2MASS H band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag[0/0.3]? Observational uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKmag[7.3/15.9]? 2MASS Ks band magnitudemagphot.mag;em.IR.Kfloatnullablee_Kmag[0/0.3]? Observational uncertainty in Kmagmagstat.error;phot.mag;em.IR.Kfloatnullable2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlchar[3.6][7.2/17.6]? Spitzer/IRAC cryomission 3.6{mu}m band magnitude (1)magphot.mag;em.IR.3-4umdoublenullablee_[3.6][0/0.31]? Observational uncertainty in [3.6] (1)magstat.errordoublenullable[4.5][6.7/17.1]? Spitzer/IRAC cryomission 4.5{mu}m band magnitude (1)magphot.mag;em.IR.4-8umdoublenullablee_[4.5][0/0.4]? Observational uncertainty in [4.5] (1)magstat.errordoublenullable[5.8][5.3/16.3]? Spitzer/IRAC cryomission 5.8{mu}m band magnitude (1)magphot.flux.density;em.IR.4-8umdoublenullablee_[5.8][0/0.9]? Observational uncertainty in [5.8] (1)magstat.errordoublenullable[8.0][3.4/15.1]? Spitzer/IRAC cryomission 8.0{mu}m band magnitude (1)magphot.flux.density;em.IR.8-15umdoublenullablee_[8.0][0/1.7]? Observational uncertainty in [8.0] (1)magstat.errordoublenullable[24][0.3/11]? Spitzer/MIPS cryomission 24{mu}m band magnitude (1)magphot.flux.density;em.IR.15-30umdoublenullablee_[24][0/1.1]? Observational uncertainty in [24] (1)magstat.errordoublenullableSpitzermeta.ref.urlintnullableCl1[0/99]? Infrared class from Gutermuth et al. 2009 (cat. J/ApJS/184/18)src.classintnullableCl2Infrared class according to Spectral Energy Distribution (SED) slope (F, I, II, or III) (G1)src.classcharVar[0/1] Variable source flag (1=yes or 0=no)meta.code;src.varintXr[0/1] Chandra counterpart flag (1=yes or 0=no)meta.codeintStd[0/1] Source in YSOVAR standard set of cluster members (1=yes or 0=no)meta.codeintAug[0/1] In the augmentation to the standard set of members (1=yes or 0=no)meta.codeintSimbadSimbad column added by the CDSmeta.ref.urlcharJ/AJ/150/145/table2Properties of X-ray sourcesVar[0/10] G-L variable indexsrc.var.indexintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSSTYSVIAU designation within the Spitzer Space Telescope (SST) Young Stellar Object VARiability (YSOVAR) program (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainRcts[5/1333] Raw X-ray countsctphot.count;em.X-rayintNcts[4/1329.3] Net X-ray countsctphot.count;em.X-rayfloatNH[0/15.7]? Fitted Hydrogen column density1e+21cm**-2phys.columnDensity;meta.modelledfloatnullablee_NH[0.03/4.3]? Error in fitted N_H_ column1e+21cm**-2stat.errorfloatnullablekT[0.2/15]? Fitted temperaturekeVphys.temperaturefloatnullablee_kT[0/29.1]? Error in kTkeVstat.error;phys.energyfloatnullablef_kT[n] Indicates kT error is nanmeta.codecharFlux1? Source flux after absorption correction (in units of erg/s/cm^2^)mW.m**-2phot.flux;em.X-raydoublenullableFlux0? Source flux without absorption correction (in units of erg/s/cm^2^)mW.m**-2phot.flux;em.X-raydoublenullablechi2[0/1.71]? Reduced {chi}^2^ of the spectral fitstat.fit.param;meta.modelledfloatnullableStatc-statistic or {chi}-data variance used? (cstat or dvar)meta.codecharProb[0/1] Probability that source is an X-ray variablestat.probabilityfloat