J/ApJ/892/91ivo://CDS.VizieR/J/ApJ/892/91doi:10.26093/cds/vizier.18920091CDSHirschauer A.S.Gray L.Meixner M.Jones O.C.Srinivasan S.,Boyer M.L.Sargent B.A.2022-01-19T08:59:33Z2021-09-13T13:41:14ZCDS support team

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

cds-question@unistra.frgalaxiesinfrared-sourcesgiant-starsinfrared-photometryyoung-stellar-objectsThe nearby (~500kpc) metal-poor ([Fe/H]~-1.2; Z~30%Z_{sun}_) star-forming galaxy NGC 6822 has a metallicity similar to systems at the epoch of peak star formation. Through identification and study of dusty and dust-producing stars, it is therefore a useful laboratory to shed light on the dust life cycle in the early universe. We present a catalog of sources combining near- and mid-IR photometry from the United Kingdom Infrared Telescope (J, H, and K) and the Spitzer Space Telescope (IRAC 3.6, 4.5, 5.8, and 8.0{mu}m and MIPS 24{mu}m). This catalog is employed to identify dusty and evolved stars in NGC 6822 utilizing three color-magnitude diagrams (CMDs). With diagnostic CMDs covering a wavelength range spanning the near- and mid-IR, we develop color cuts using kernel density estimate (KDE) techniques to identify dust-producing evolved stars, including red supergiant (RSG) and thermally pulsing asymptotic giant branch (TP-AGB) star candidates. In total, we report 1292 RSG candidates, 1050 oxygen-rich AGB star candidates, and 560 carbon-rich AGB star candidates with high confidence in NGC 6822. Our analysis of the AGB stars suggests a robust population inhabiting the central stellar bar of the galaxy, with a measured global stellar metallicity of [Fe/H]=-1.286+/-0.095, consistent with previous studies. In addition, we identify 277 young stellar object (YSO) candidates. The detection of a large number of YSO candidates within a centrally located, compact cluster reveals the existence of an embedded, high-mass star formation region that has eluded previous detailed study. Spitzer I appears to be younger and more active than the other prominent star-forming regions in the galaxy.2020ApJ...892...91Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/892/91CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/121/2020 : CTIO and WFPC2 photometry in NGC 6822 (Bianchi+, 2001)J/ApJ/851/152 : DUSTiNGS. IV. AGB spectral types with HST (Boyer+, 2017)J/AJ/142/103 : Cool evolved stars in SAGE-SMC and SAGE-LMC (Boyer+, 2011)J/ApJ/800/51 : DUSTiNGS II. Metal-poor dusty AGB stars (Boyer+, 2015)J/ApJ/810/116 : S-type AGB stars in SMC (Boyer+, 2015)J/ApJS/216/10 : DUSTiNGS. I. The Good Source Catalog (Boyer+, 2015)J/A+A/542/A66 : YSOs in 9 LMC star forming regions (Carlson+, 2012)J/A+A/429/837 : IJKs photometry of late-type stars in NGC 6822 (Cioni+, 2005)J/A+A/448/181 : IR colours of AGB and post-AGB stars (Groenewegen+, 2006)J/A+A/495/447 : PN and HII regions in NGC6822 (Hernandez-Martinez+, 2009)J/ApJS/162/49 : UBV imaging of irregular galaxies (Hunter+, 2006)J/MNRAS/470/3250 : SAGE LMC point-sources classification (Jones+, 2017)J/ApJ/811/145 : LMC & SMC evolved stars detected with Herschel (Jones+, 2015)J/ApJ/841/15 : Synthetic JWST/MIRI fluxes and magnitudes (Jones+, 2017)J/ApJ/854/117 : NIR stellar populations in Sextans A and Leo A (Jones+, 2018)J/A+A/537/A108 : NGC 6822 AGB spectroscopic catalogue (Kacharov+, 2012)J/A+A/454/717 : NIR photometry of C and AGB stars in NGC 6822 (Kang+, 2006)J/PASP/122/683 : SAGE-Spec Spitzer legacy program (Kemper+, 2010)J/ApJ/715/1094 : Census of self-obscured massive stars (Khan+, 2010)J/ApJS/219/42 : Spitzer point source catalogs in 7 nearby gal. (Khan+, 2015)J/ApJ/834/9 : Spectroscopy obs. of LeoA, Aqr & Sgr dwarf gal. (Kirby+, 2017)J/AJ/123/832 : C star population in NGC 6822 (Letarte+, 2002)J/ApJ/858/11 : NIR tip of RGB. I. JHK photometry of IC1613 (Madore+, 2018)J/AJ/109/173 : BVR photometry of NGC 6822 (Marconi+ 1995)J/AJ/110/2715 : UBV photometry in NGC 6822, M31 and M33 (Massey+ 1995)J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)J/AJ/146/62 : HERschel HERITAGE in Magellanic Clouds (Meixner+, 2013)J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)J/AJ/138/1203 : Star formation regions in nearby dwarf gal. (Melena+, 2009)J/ApJ/753/71 : Mass-loss return from LMC evolved stars. VI. (Riebel+, 2012)J/MNRAS/451/3504 : Classification of IRS sources in the SMC (Ruffle+, 2015)J/ApJ/744/20 : S^4^MC project: 6 star forming regions PAHs (Sandstrom+, 2012)J/ApJ/835/278 : Molecular clouds in the dwarf galaxy NGC6822 (Schruba+, 2017)J/ApJ/699/150 : Spectral classifications of Massive YSOs in LMC (Seale+, 2009)J/AJ/148/124 : Herschel key program Heritage (Seale+, 2014)J/ApJ/778/15 : SAGE-SMC III. Young stellar objects (Sewilo+, 2013)J/A+A/540/A135 : AGB population of NGC 6822 (Sibbons+, 2012)J/A+A/574/A102 : AGB candidates in NGC 6822 (Sibbons+, 2015)J/MNRAS/457/2814 : SAGE SMC evolved stars candidates (Srinivasan+, 2016)J/MNRAS/428/2216 : JHKs photometry of AGB stars in NGC 6822 (Whitelock+, 2013)J/AJ/136/18 : LMC SAGE. New candidate YSOs (Whitney+, 2008)J/MNRAS/411/1597 : LMC point source classification in SAGE-Spec (Woods+, 2011)J/MNRAS/400/1413 : Near-IR spectra of extremely red AGB stars (Wright+, 2009)J/A+A/616/A175 : Red supergiant stars in the LMC. II. (Yang+, 2018)J/A+A/629/A91 : A source catalog for the SMC (Yang+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/892/91https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/892/91http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/892/91https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/892/91https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/892/91http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/892/91GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/892/91/table1 (The master catalog)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/892/91/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/892/91/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/892/91/table1?GETtext/xml+votable180.050000true296.37946-14.745450.0055555555555555566/29716 297186.772611666688002e-21 1.6867587740958882e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/892/91?format=asciiInfrareddefaultJ/ApJ/892/91/table1The master catalogAGBAGB classification (2)(3)meta.codechar5.8mag[8.4/18.3]? Spitzer/IRAC 5.8um band magnitudemagphot.flux.density;em.IR.4-8umdoublenullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqMIR unique identifier (<[KSK2015] JDDD.ddddd+DD.ddddd> in Simbad)meta.id;meta.mainintRAJ2000[296.02/296.46] MIR right ascension (J2000)degpos.eq.ra;meta.mainindexedDEJ2000[-14.98/-14.62] MIR declination (J2000)degpos.eq.dec;meta.mainindexed3.6mag[9/20.3] Spitzer/IRAC 3.6um band magnitudemagphot.mag;em.IR.3-4umfloate_3.6mag[0.02/0.3] Uncertainty in 3.6magmagstat.errorfloat4.5mag[8.9/19.7] Spitzer/IRAC 4.5um band magnitudemagphot.mag;em.IR.4-8umfloate_4.5mag[0.02/0.3] Uncertainty in 4.5magmagstat.errorfloate_5.8mag[0.01/0.3]? Uncertainty in 5.8magmagstat.errordoublenullable8.0mag[8.5/17.7]? Spitzer/IRAC 8.0um band magnitudemagphot.flux.density;em.IR.8-15umdoublenullablee_8.0mag[0.01/0.3]? Uncertainty in 8.0magmagstat.errordoublenullable24mag[2.9/15.8]? Spitzer/MIPS 24um band magnitudemagphot.flux.density;em.IR.15-30umdoublenullablee_24mag[0.01/0.3]? Uncertainty in 24magmagstat.errordoublenullableNIR-ID[93314/141942]?=-9999 NIR unique identifier (<[SRC2012] DDD.dddddd+DD.dddddd> in Simbad)(1)meta.id.crossintnullableRANdeg? NIR right ascension (J2000) (1)degpos.eq.ranullableDENdeg? NIR declination (J2000) (1)degpos.eq.decnullableSep[0.005/1]? Distance to nearest-neighbor near-infrared sourcearcsecpos.angDistancedoublenullableJmag[10.6/27.3]? Apparent UKIRT/WFCAM J band magnitude (1)(2)magphot.mag;em.IR.Jdoublenullablee_Jmag[0.001/6]? Uncertainty in Jmagmagstat.error;phot.magdoublenullableHmag[10.7/27.7]? Apparent UKIRT/WFCAM H band magnitude (1)(2)magphot.mag;em.IR.Hdoublenullablee_Hmag[0.001/7]? Uncertainty in Hmagmagstat.error;phot.magdoublenullableKmag[9.2/19.4]? Apparent UKIRT/WFCAM K band magnitude (1)(2)magphot.mag;em.IR.Kdoublenullablee_Kmag[0.001/0.4]? Uncertainty in Kmagmagstat.error;phot.magdoublenullableCMD1[1/5]? Numerical Region Categorization for CMD 1: K vs. J-K (4)meta.codeintnullableCMD2[1/5]? Numerical Region Categorization for CMD 2: [3.6] vs J-[3.6] (4)meta.codeintnullableCMD3[1/6]? Numerical Region Categorization for CMD 3: [8.0] vs [3.6]-[8.0] (4)meta.codeintnullableClassFinal type classification (5)src.classchar