J/ApJS/254/33ivo://CDS.VizieR/J/ApJS/254/33doi:10.26093/cds/vizier.22540033CDSKuhn M.A.de Souza R.S.Krone-Martins A.Castro-Ginard A.Ishida E.E.O.,Povich M.S.Hillenbrand L.A. (The COIN Collaboration)2022-01-19T09:09:49Z2021-09-17T09:34:14ZCDS support team

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

cds-question@unistra.fryoung-stellar-objectsastronomical-object-identificationinfrared-photometrygalaxy-planesmilky-way-galaxyvisible-astronomyphotometryproper-motionsstellar-associationssurveysWe present ~120000 Spitzer/IRAC candidate young stellar objects (YSOs) based on surveys of the Galactic midplane between l~255{deg} and 110{deg}, including the GLIMPSE I, II, and 3D, Vela-Carina, Cygnus X, and SMOG surveys (613 square degrees), augmented by near-infrared catalogs. We employed a classification scheme that uses the flexibility of a tailored statistical learning method and curated YSO data sets to take full advantage of Spitzer's spatial resolution and sensitivity in the mid-infrared ~3-9{mu}m range. Multiwavelength color/magnitude distributions provide intuition about how the classifier separates YSOs from other red IRAC sources and validate that the sample is consistent with expectations for disk/envelope-bearing pre-main-sequence stars. We also identify areas of IRAC color space associated with objects with strong silicate absorption or polycyclic aromatic hydrocarbon emission. Spatial distributions and variability properties help corroborate the youthful nature of our sample. Most of the candidates are in regions with mid-IR nebulosity, associated with star-forming clouds, but others appear distributed in the field. Using Gaia DR2 distance estimates, we find groups of YSO candidates associated with the Local Arm, the Sagittarius-Carina Arm, and the Scutum-Centaurus Arm. Candidate YSOs visible to the Zwicky Transient Facility tend to exhibit higher variability amplitudes than randomly selected field stars of the same magnitude, with many high-amplitude variables having light-curve morphologies characteristic of YSOs. Given that no current or planned instruments will significantly exceed IRAC's spatial resolution while possessing its wide-area mapping capabilities, Spitzer-based catalogs such as ours will remain the main resources for mid-infrared YSOs in the Galactic midplane for the near future.2021ApJS..254...33Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJS/254/33CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/328 : AllWISE Data Release (Cutri+ 2013)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/360 : Gaia DR2 x AllWISE catalogue (Marton+, 2019)II/364 : VIRAC. The VVV Infrared Astrometric Catalogue (Smith+, 2019)II/368 : The Spitzer (SEIP) source list (SSTSL2) (Spitzer Science Center, 2021)J/ApJ/670/428 : Bubbles in the galactic disk. II. (Churchwell+, 2007)J/ApJ/663/1149 : Spitzer survey of Serpens YSO population (Harvey+, 2007)J/ApJ/669/327 : S3MC: YSOs in N66, in SMC (Simon+, 2007)J/ApJ/674/336 : Spitzer observations of NGC 1333 (Gutermuth+, 2008)J/AJ/136/2413 : Galactic midplane Spitzer red sources (Robitaille+, 2008)J/ApJS/181/321 : Properties of Spitzer c2d dark clouds (Evans+, 2009)J/ApJS/184/18 : Spitzer survey of young stellar clusters (Gutermuth+, 2009)J/ApJ/706/83 : Embedded YSO candidates in W51 (Kang+, 2009)J/ApJ/693/L81 : Extinction in star-forming regions (McClure, 2009)J/ApJ/696/1278 : The extended star-forming environment of M17 (Povich+, 2009)J/AJ/138/1116 : A Spitzer view of NGC 2264 (Sung+, 2009)J/ApJ/720/679 : Optical spectroscopy in Cygnus X region (Beerer+, 2010)J/ApJ/714/778 : YSOs in the Serpens Molecular Cloud (Oliveira+, 2010)J/ApJS/194/14 : A Pan-Carina YSO catalog (Povich+, 2011)J/ApJS/193/25 : The NAN complex. II. MIPS observations (Rebull+, 2011)J/MNRAS/424/2442 : Catalog of bubbles from Milky Way Project (Simpson+, 2012)J/ApJS/208/11 : Red MSX Source Survey: massive protostars (Lumsden+, 2013)J/ApJS/209/31 : The MYStIX IR-Excess Source catalog (MIRES) (Povich+, 2013)J/ApJS/212/1 : The WISE catalog of Galactic HII regions (Anderson+, 2014)J/A+A/566/A122 : JHK and IRAC photometry of Sh2-90 YSOs (Samal+, 2014)J/A+A/578/A51 : Near-IR photometry of AGB stars in IC 1613 (Chun+, 2015)J/AJ/149/64 : MIPSGAL 24{mu}m point source catalog (Gutermuth+, 2015)J/ApJ/802/60 : Structure of young stellar clusters. II. (Kuhn+, 2015)J/MNRAS/447/2307 : Galactic HII region IRAS 16148-5011 content (Mallick+, 2015)J/MNRAS/458/3479 : SVM selection of WISE YSO Candidates (Marton+, 2016)J/MNRAS/465/3011 : VVV high amplitude NIR var. stars (Contreras Pena+, 2017)J/A+A/597/A90 : rho Oph proper motions and photometry (Ducourant+, 2017)J/A+A/617/A33 : HRS sample, dust, gas mass functions (Andreani+, 2018)J/MNRAS/473/3671 : Galactic bubble infrared fluxes (Bufano+, 2018)J/AJ/156/71 : K2 Campaign 2: young disk-bearing stars (Cody+, 2018)J/ApJS/236/27 : APOGEE-2 survey of Orion Complex (OSFC). I. (Cottle+, 2018)J/AJ/156/271 : The stellar membership of the Taurus SFR (Luhman, 2018)J/A+A/620/A172 : Solar neighbourhood young stars 3D mapping (Zari+, 2018)J/ApJ/878/111 : Members in Serpens with Gaia DR2 (Herczeg+, 2019)J/MNRAS/488/1141 : MW Project DR2 bubbles & bow shocks (Jayasinghe+, 2019)J/AJ/158/122 : Local structure & SFH of the MW (Kounkel+, 2019)J/ApJ/880/9 : Spitzer obs. of YSOs in the SMOG field (Winston+, 2019)J/A+A/635/A45 : New open clusters in Galactic disc (Castro-Ginard+, 2020)J/AJ/160/279 : Untangling the Galaxy. II. within 3kpc (Kounkel+, 2020)J/AJ/159/200 : YSOs in Lupus star-forming region (Melton, 2020)J/A+A/633/A51 : Distances to molecular clouds in SFR (Zucker+, 2020)J/ApJS/249/18 : The ZTF catalog of periodic variable stars (Chen+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJS/254/33https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJS/254/33http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJS/254/33https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJS/254/33https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJS/254/33http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJS/254/33GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJS/254/33/table1 (Spitzer/IRAC Candidate YSOs (SPICY))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/254/33/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/254/33/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/254/33/table1?GETtext/xml+votable180.050000true125.66481111-37.551348890.005555555555555556Cone search capability for table J/ApJS/254/33/table2 (*YSO groups from HDBSCAN)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/254/33/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/254/33/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/254/33/table2?GETtext/xml+votable180.050000true126.8138949-38.48199090.005555555555555556Cone search capability for table J/ApJS/254/33/fig25 (ZTF light curves for 7585 YSO candidates showing strong variability)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJS/254/33/fig25?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJS/254/33/fig25?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJS/254/33/fig25?GETtext/xml+votable180.050000true288.794573810.3175560.0055555555555555564/1801 1803 1806-1807 1891 2652 5/3242 3567 3578 3585 3588-3589 3600-3601 3603 3655 3661 3666-3667 3670 3672-3674 3905 3907-3910 7183 7201-7203 7208-7209 7216 7218-7219 7222-7223 7266 7272 7274-7275 7278-7279 7291 7365 7376-7378 7382-7383 7389 7552 7554 7560-7561 7578-7579 7604-7605 7648 7650-7651 7654 7661 7672-7673 7678-7679 9335 9341 9343 9429 9431 9436 9438 9460 9462 9468 9470 9475-9476 9480-9482 9504 9506 9812 9814 9820 9822 9844 10399 10413-10414 10418-10421 10424 10441-10445 10450-10451 10453 10538-10539 10542-10543 10552-10554 10556-10557 10590 10593-10595 10597-10600 10604 10612 10614-10615 10617 10624-10625 10753 10755-10756 10760 6/12972 12974-12975 12986-12987 12990 14255 14266-14267 14307 14336-14337 14361 14364-14365 14408-14409 14411 14652-14653 14655 14659 14662-14663 14674 14684 14686 14700-14701 14704-14706 15625-15627 15644-15646 15648 15680-15682 15688 28715 28718-28719 28729-28731 28776 28778-28779 28801-28803 28844-28845 28847 28868 28870-28871 28882-28883 29070 29092 29094-29095 29106 29161-29163 29201 29204-29205 29265 29268-29269 29440-29442 29445 29456-29457 29471 29516-29518 29520 29522-29523 29526-29527 29537 29565 30212 30214 30220 30222-30223 30233-30236 30238-30239 30248-30249 30282 30306-30307 30328 30330-30331 30334 30352-30353 30356 30358 30401 30404-30405 30407 30428-30429 30598-30599 30620 30622-30623 30629 30640-30641 30666-30667 30697 30700-30701 30703-30704 30706-30707 30710-30711 32084-32085 37245 37247 37333-37335 37363 37369 37371 37713 37715 37721 37723 37748-37750 37756 37758 37839 37844 37846 37852 37854 37861 37863 37869 37871 37876 37884 37886 37891 37893-37895 37897-37899 37908 37910 37912 37914 37932 37934 38020 38048 38050 38056 38058 39247 39252 39254 39260 39262 39269 39271 39277 39279 39284 41595 41631 41647 41651 41660-41662 41669-41671 41688-41689 41700 41704 41754-41755 41757-41759 41762-41763 41784 41798-41799 41809-41811 41816-41818 41820-41821 41824-41825 41856-41857 42147 42150-42151 42165-42167 42186-42187 42190 42202-42203 42206-42207 42220-42222 42299 42302-42303 42346 42349 42351 42370-42371 42385-42387 42404-42406 42408-42409 42420-42422 42452 42454-42455 42467 42480 42505 42507-42509 42512-42514 42517 42560-42561 42564 43011 43017-43019 43028 43032 43044 430482.0616683193919197e-20 6.185923063528282e-20https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJS/254/33?format=asciiOpticalInfrareddefaultJ/ApJS/254/33/table1Spitzer/IRAC Candidate YSOs (SPICY)LCInteractive LC Plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSPICY[1/117446]? SPICY designationmeta.id;meta.mainintnullableRA_ICRS[125.6/346.5] Right ascension (ICRS)degpos.eq.ra;meta.mainindexedDE_ICRS[-64/62.4] Declination (ICRS)degpos.eq.dec;meta.mainindexedGLONGalactic longitude (GLON)degpos.galactic.lonGLATGalactic latitude (GLAT)degpos.galactic.latdoublep1[0/1]? YSO random forest score from IRAC+2MASS photometry (1)stat.fit.goodnessfloatnullablep2[0/1]? YSO random forest score from IRAC+UKIDSS photometry (1)stat.fit.goodnessfloatnullablep3[0/1]? YSO random forest score from IRAC+VVV photometry (1)stat.fit.goodnessfloatnullableclassYSO class (2)src.classcharSi[0/1] Flag for a possible strong silicate feature (silicate)meta.codeintPAH[0/1] Flag for a possible strong PAH featuremeta.codeintalpha[-3.1/6.1]? Spectral index used for YSO class (3)spect.indexdoublenullablealpha8[-2.4/6.1]? Spectral index derived from the [4.5]-[8.0] color (alpha8)spect.indexfloatnullablealpha24[-3.1/3.2]? Spectral index derived from the [4.5]-[24] color (alpha24)spect.indexfloatnullablealphaW4[-2.3/3.5]? Spectral index derived from the [4.5]-W4 color (alphaW4)spect.indexfloatnullableEnvClassification of the YSO environment from the 3'x3' IRAC cutout (4)meta.code.class;src.classcharGroupHDBSCAN group (as in Table 2) to which the star is assignedmeta.id.parentcharvar[1/3]? ZTF light-curve variability flag (3=high variability) (5)meta.code;src.varintnullableo_ZTFrmag[10/319]? Number of good ZTF r-band observations used (n_ZTFrmag)meta.numberintnullableZTFrmag[12.4/21.5]? ZTF mean magnitude in the r-bandphot.mag;em.opt.Rfloatnullablee_ZTFrmag[0.009/1.2]? ZTF light-curve {sigma}_var_ standard deviation in the rbandstat.errorfloatnullableskew[-10/11.1]? ZTF light-curve skew in the rband (skewness)stat.fit.paramfloatnullableSpitzerSpitzer source designation from GLIMPSE ("SSTCYGXC", "SSTGLMC", "SSTSMOGC" or "SSTVELC" sources)meta.idchar3.6mag[7/17] Spitzer/IRAC 3.6um band magnitudemagphot.mag;em.IR.3-4umfloate_3.6mag[0.016/0.4] Uncertainty on the 3.6magmagstat.errorfloat4.5mag[6.5/14.5] Spitzer/IRAC 4.5um band magnitudemagphot.mag;em.IR.4-8umfloate_4.5mag[0.014/0.4] Uncertainty on the 4.5magmagstat.errorfloat5.8mag[4.5/14.1]? Spitzer/IRAC 5.8um band magnitudemagphot.flux.density;em.IR.4-8umfloatnullablee_5.8mag[0.01/0.4]? Uncertainty on the 5.8magmagstat.errorfloatnullable8.0mag[4/13.3]? Spitzer/IRAC 8um band magnitudemagphot.flux.density;em.IR.8-15umfloatnullablee_8.0mag[0.009/0.4]? Uncertainty on the 8.0magmagstat.errorfloatnullablecsf[0/2]? GLIMPSE close source flag (6)meta.codeintnullableo_3.6mag[1/24]? Number of detections in the 3.6um band (n_3.6mag)meta.numberintnullableo_4.5mag[1/18]? Number of detections in the 4.5um band (n_4.5mag)meta.numberintnullableo_5.8mag[0/24]? Number of detections in the 5.8um band (n_5.8mag)meta.numberintnullableo_8.0mag[0/20]? Number of detections in the 8.0um band (n_8.0mag)meta.numberintnullable2MASS2MASS source name (HHMMSSss+DDMMSSs; J2000)meta.id.crosscharUKIDSSUKIDSS source designation (JHHMMSS.ss+DDMMSS.s)meta.id.crosscharVIRAC? VIRAC DR1 source designationmeta.id.crosslongnullableGaiaDR2? Gaia DR2 source designationmeta.id.crossnullableMIPSSpitzer/MIPS source designationmeta.id.crosscharWISEAAllWISE source designation (JHHMMSS.ss+DDMMSS.s) (AllWISE)meta.id.crosscharZTFDR3? ZTF DR3 source designationmeta.id.crossnullableNpNumber of photometry measurements for this star (link to fig25.dat)meta.numberintnullableJ/ApJS/254/33/table2*YSO groups from HDBSCANrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGroupGroup designation (GLL.l+B.b)meta.id;meta.maincharprimaryGLONCentral Galactic longitude (l0) (1)degpos.galactic.lonGLAT[-2.62/3.63] Central Galactic latitude (b0) (1)degpos.galactic.latplx[0.05/1.7]? Mean parallax (1)maspos.parallax.trigfloatnullablee_plx[0.04/0.7]? Parallax uncertainty (1)masstat.error;pos.parallaxfloatnullablepmGLON[-14/1]? Mean proper motion in GLON (pml) (1)pos.pm;stat.meanfloatnullablee_pmGLON[0.07/3.1]? pmGLON uncertainty (e_pml) (1)stat.errorfloatnullablepmGLAT[-4.3/6.6]? Mean proper motion in GLAT (pmb) (1)pos.pm;stat.meanfloatnullablee_pmGLAT[0.07/2.6]? pmGLAT uncertainty (e_pmb) (1)stat.errorfloatnullableNtot[30/3662]? Total number of constituents (n)meta.numberintnullableN5G[0/412]? Number of constituents with five-parameter Gaia astrometric solutions (nG)meta.numberintnullableFlag[f] Flag for potential model problems (see Section 7.1)meta.code.errorchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.ranullableindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decnullableindexedJ/ApJS/254/33/fig25ZTF light curves for 7585 YSO candidates showing strong variabilityqID[1/4]? Quadrant IDmeta.id;instrintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID? Object identifier (oid)meta.idnullableExpID[44350541/109212187]? Exposure IDmeta.idlongnullableHJDHeliocentric Julian Datedtime.epochdoubleindexedMJD[58197.5/58846.2] Modified Julian Date (HJD-24000000.5)dtime.epochdoublemag[12.22/22.23] ZTF magnitudemagphot.mag;em.opt.Rfloate_mag[0/0.5] Uncertainty in mag (magerr)magstat.error;phot.magfloatFlags[0/4352]? Catalog flags for source from PSF-fitting catalog (catflags)meta.code.errorintnullableFilt[zr] Catalog filter code; always "zr" = R-band observations (filtercode)meta.notecharRAJ2000Right ascension (J2000) (ra)degpos.eq.ra;meta.mainindexedDEJ2000Declination (J2000) (dec)degpos.eq.dec;meta.mainindexedchi2[0.03/35] Chi-squared statistic for PSF fit (chi)stat.fit.chi2floatsharp[-2/3.3] Sharpness of sourcestat.fit.paramdoubleFracDay? Exposure file time stamp, with decimal representation YYYYMMDDdddddd: year, month, day, and fractional day (filefracday)time.epochnullableField[280/1861]? Field identifiermeta.id;obs.fieldintnullableCCD[1/16]? CCD number (ccdid)meta.id;instrintnullablemagLim[17.7/22.1] Approximate 5-sigma limiting magnitude corresponding to epoch-based PSF-fit catalog (limitmag)magphot.magfloatmagZP[25.39/26.5] Magnitude zeropoint from photometric calibrationmagphot.mag;arith.zpdoublee_magZP[0.01/0.05] RMS deviation in magnitude zeropoint (magzprms)magstat.errorfloatCol[-0.016/0.2] Color coefficient from linear fit (clrcoeff)stat.fit.paramfloate_Col[1.3e-6/0.0007] Color coefficient uncertainty from linear fit (clrcounc)stat.errordoubleExp[30] Exposure time from scheduler (always "30") (exptime)stime.duration;obs.exposureintAirmass[1/2.91] Airmass at approximately the center of the focal plane at time of exposureobs.airMassfloatPID[1/3]? Program ID (programid)meta.id;obsintnullableSPICY[53590/117446] SPICY designationmeta.id;meta.mainintSpitzerDesignation of the Spitzer source (sst_desig)meta.idchar