J/ApJ/914/28ivo://CDS.VizieR/J/ApJ/914/28doi:10.26093/cds/vizier.19140028CDSMedina N.Borissova J.Kurtev R.Alonso-Garcia J.Roman-Zuniga C.G.,Bayo A.Kounkel M.Roman-Lopes A.Lucas P.W.Covey K.R.Forster F.,Minniti D.Adame L.Hernandez J.2023-01-31T12:57:14Z2022-12-28T14:03:12ZCDS support team

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

cds-question@unistra.frstar-forming-regionsvariable-starsyoung-stellar-objectsinfrared-photometryinfrared-astronomyspectroscopyWe present a catalog of 167 newly discovered, irregular variables spanning a ~7deg^2^ area that encompasses the G305 star-forming complex, one of the most luminous giant HII regions in the Galaxy. We aim to unveil and characterize the young stellar object (YSO) population of the region by analyzing the Ks-band variability and JHKs infrared colors from the VISTA Variables in the Via Lactea survey. Additionally, SDSS-IV APOGEE-2 infrared spectra of selected objects are analyzed. The sample shows relatively high amplitudes (0.661mag<{Delta}K_S_<3.521mag). Most of them resemble sources with outbursts with amplitude >1mag and duration longer than a few days, typically at least a year, known as eruptive variables. About 60% are likely to be Class II/flat/I objects. This is also confirmed by the spectral index {alpha} when available. From the analysis of APOGEE-2 near-infrared spectra of sources in the region, another 122 stars are classified as YSOs and display some infrared variability. The measured effective temperature Teff peak is around 4000 K, and they are slightly supersolar in metal abundance. The modal radial velocity is approximately -41km/s. Combining available catalogs of YSOs in the region with our data, we investigate the spatial distributions of 700 YSOs. They are clearly concentrated within the central cavity formed by the massive clusters Danks 1 and 2. The calculated surface density for the entire catalog is 0.025 YSOs pc^-2^, while the central cavity contains 10 times more objects per area (0.238 YSOs pc^-2^).2021ApJ...914...28Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/914/28CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)II/337 : VISTA Variables in the Via Lactea Survey DR1 (Saito+, 2012)II/328 : AllWISE Data Release (Cutri+ 2013)II/348 : VISTA Variable in the Via Lactea Survey DR2 (Minniti+, 2017)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)II/364 : VIRAC. The VVV Infrared Astrometric Catalogue (Smith+, 2019)IX/57 : The Chandra Source Catalog (CSC), Release 2.0 (Evans+, 2019)II/360 : Gaia DR2 x AllWISE catalogue (Marton+, 2019)III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)J/AJ/121/3160 : JHK photometry near the Trapezium region (Carpenter+, 2001)J/A+A/432/737 : General Cat. of 6.7GHz Methanol Masers (Pestalozzi+, 2005)J/A+A/492/277 : Analysis of Collinder 69 stars with VOSA (Bayo+, 2008)J/AJ/136/2391 : GLIMPSE Extended Green Objects catalog (Cyganowski+, 2008)J/AJ/136/2413 : Galactic midplane Spitzer red sources (Robitaille+, 2008)J/A+A/532/A131 : New Galactic star clusters in VVV survey (Borissova+, 2011)J/ApJS/196/9 : 95GHz methanol maser survey toward GLIMPSE EGOs (Chen+, 2011)J/AJ/143/70 : Differential reddening in MW globulars (Alonso-Garcia+, 2012)J/AJ/147/82 : Monitoring of disk-bearing stars in NGC 2264 (Cody+, 2014)J/AJ/149/64 : MIPSGAL 24{mu}m point source catalog (Gutermuth+, 2015)J/AJ/150/132 : JHK photometry of 1203 variables in ONC (Rice+, 2015)J/AJ/150/145 : YSOVAR infrared photometry in GGD12-15 (Wolk+, 2015)J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)J/A+A/591/A149 : Hi-GAL. inner Milky Way: +68>=l>=70 (Molinari+, 2016)J/MNRAS/465/3011 : VVV high amplitude NIR var. stars (Contreras Pena+, 2017)J/MNRAS/464/1247 : VVV high PM stars. I. Ks<=13.5 stars (Kurtev+, 2017)J/ApJ/864/11 : The VVV Variables (V^4^) catalog (Medina+, 2018)J/A+A/619/A41 : Photometric variability of massive YSOs (Teixeira+, 2018)J/A+A/623/A110 : Gaia DR2. Variable stars in CMD (Gaia Collaboration+, 2019)J/A+A/647/A169 : VVV survey near-infrared colour catalogue (Herpich+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/914/28https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/914/28http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/914/28https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/914/28https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/914/28http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/914/28GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/914/28/table4 (Parameters of the VVV variables considered in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/914/28/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/914/28/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/914/28/table4?GETtext/xml+votable180.050000true194.04540806-63.311268890.0055555555555555565/10413 10415 6/41651 41657 41659 41674 41696 416986.772611666688002e-21 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/914/28?format=asciiInfrareddefaultJ/ApJ/914/28/table4Parameters of the VVV variables considered in this workVClassVariable Class (3)src.classcharMIPSGALDisplay data from MIPSGAL 24um cat. (Gutermuth+ 2015, J/AJ/149/64) within 1.5" (if 24um is measured)meta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000[194/200.51] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[-64/-61.6] Declination (J2000)degpos.eq.dec;meta.mainGLON[303.4/306.4] Galactic longitudedegpos.galactic.lonGLAT[-1.16/1.11] Galactic latitudedegpos.galactic.latdoubleKsmag[11.29/16.5] Mean Ks-band magnitude of variablemagphot.mag;em.IR.Kfloate_Ksmag[0.01/0.07] Standard deviation of Ksmag observationsmagstat.error;phot.magfloatn_Ksmag[22/69] Number of Ks observationsmeta.noteintDelKs[0.66/3.53] Total amplitude variability parameter (1)src.var.amplitude;em.IR.Kfloateta[0.049/1.06] {eta} index variability parameter (1)src.var.amplitude;em.IR.KfloatKsmag0[11.78/17.37]? Ksmag on MJD=55264magphot.mag;em.IR.Kfloatnullablee_Ksmag0[0.016/0.1]? Uncertainty in Ksmag on MJD=55264magstat.error;phot.magfloatnullableJmag[12.81/19.7]? Mean J-band magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag[0.013/0.22]? Uncertainty in Jmagmagstat.error;phot.magfloatnullableHmag[12.61/18.86]? Mean H-band magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag[0.01/0.94]? Uncertainty in Hmagmagstat.error;phot.magfloatnullableJ-H[-0.05/3.73]? Mean J-H color indexmagphot.color;em.IR.J;em.IR.HfloatnullableH-Ks[-0.15/4]? Mean H-Ks color indexmagphot.color;em.IR.H;em.IR.Kfloatnullable[3.6][7.7/14.94]? GLIMPSE IRAC 3.6um band magnitudemagphot.mag;em.IR.3-4umfloatnullablee_[3.6][0.028/0.4]? Uncertainty in [3.6]magstat.errorfloatnullable[4.5][6.89/14.5]? GLIMPSE IRAC 4.5um band magnitudemagphot.mag;em.IR.4-8umfloatnullablee_[4.5][0.029/0.3]? Uncertainty in [4.5]magstat.errorfloatnullable[5.8][4/13.22]? GLIMPSE IRAC 5.8um band magnitudemagphot.flux.density;em.IR.4-8umfloatnullablee_[5.8][0.019/0.4]? Uncertainty in [5.8]magstat.errorfloatnullable[8.0][4.2/12.74]? GLIMPSE IRAC 8.0um band magnitudemagphot.flux.density;em.IR.8-15umfloatnullablee_[8.0][0.016/0.4]? Uncertainty in [8.0]magstat.errorfloatnullable[24][0.5/9.31]? MIPSGAL 24um band magnitudemagphot.flux.density;em.IR.15-30umfloatnullablee_[24][0.02/0.4]? Uncertainty in [24]magstat.errorfloatnullableW1mag[8.36/15.1]? ALLWISE W1-band (3.4um) magnitudemagphot.mag;em.IR.3-4umfloatnullablee_W1mag[0.02/0.31]? Uncertainty in W1magmagstat.error;phot.magfloatnullableW2mag[5.036/13.75]? ALLWISE W2-band (4.6um) magnitudemagphot.mag;em.IR.4-8umfloatnullablee_W2mag[0.017/0.2]? Uncertainty in W2magmagstat.error;phot.magfloatnullableW3mag[2.34/12.5]? ALLWISE W3-band (12um) magnitudemagphot.flux.density;em.IR.8-15umfloatnullablee_W3mag[0.012/0.5]? Uncertainty in W3magmagstat.error;phot.magfloatnullableW4mag[-0.68/9.05]? ALLWISE W4-band (22um) magnitudemagphot.flux.density;em.IR.15-30umfloatnullablee_W4mag[0.004/0.43]? Uncertainty in W4magmagstat.error;phot.magfloatnullablealpha[-3.56/3.31]? IR spectral index, {alpha} (6)spect.index;em.IRfloatnullableVVVDisplay data from VVV DR1 (II/337) and DR2 (II/348) within 0.5"meta.ref.urlintnullableWISEDisplay data from WISE (II/311) and AllWISE (II/328) within 1.5" (if W1mag is measured)meta.ref.urlcharOIDObject Identifier (TileID: d045, d046, d083 or d084 and vNN within tile with numbers from v1 to v66)meta.id;meta.maincharTileIDVVV Tile identifier (d045, d046, d083 or d084)obs.fieldcharClassOptical Class "F, T, or P" (2)meta.code.classcharCommComments (4)meta.notecharRefReference (5)meta.ref;pos.framecharAClassClassification from {alpha} slope (7)src.classcharGLIMPSEDisplay data from GLIMPSE (II/293) within 1.5" (if 3.6um is measured)meta.ref.urlchar