J/ApJ/961/176ivo://CDS.VizieR/J/ApJ/961/176CDSBiswas S.Mondal S.Hoque A.Panja A.Baug T.Das R.2026-05-27T11:58:45Z2026-05-27T11:56:56ZCDS support team

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

cds-question@unistra.frinfrared-photometryvisible-astronomybroad-band-photometrystellar-distanceyoung-stellar-objectsh-ii-regionsh-alpha-photometryWe present a detailed study of the Sh2-87 HII region using a multiwavelength data set in optical to radio bands. A Herschel column density map revealed that the host cloud is filamentary in nature, and together they formed a central dense hub. The extinction map generated using near-infrared photometric data also signifies the nonuniform distribution of the cloud and reveals its filamentary nature. We estimated a sizable variable extinction over the region up to A_V_=34.4mag, with an average value of A_V_=3.4mag. Using the various infrared color-color criteria, we identified 13 Class I and 202 Class II young stellar objects (YSOs) and 22 H{alpha}-emitting sources toward this region. Further analysis showed that the cluster is mainly composed of low-mass YSOs with a typical age of ~3Myr having masses in the range of 0.1-6.0M_{sun}_. The identified evolved YSOs (i.e., Class II YSOs) are primarily distributed along the filaments and in the outer parts of the cloud, while the recent star formation, inferred by the presence of Class I YSOs, ionized gas, and star-forming clumps, is observed in the hub region. The overall star formation scenario in the Sh2-87 region resembles the global hierarchical collapse model of star formation, where younger massive star formation activity is expected at the central hub along with the distribution of evolved low-mass YSOs in the filaments and the outer parts of the cloud.2024ApJ...961..176Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/961/176CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/20 : Catalogue of HII Regions (Sharpless 1959)VIII/65 : 1.4GHz NRAO VLA Sky Survey (NVSS) (Condon+ 1998)VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)II/293 : GLIMPSE Source Catalog (I + II + 3D) (IPAC 2008)II/316 : UKIDSS-DR6 Galactic Plane Survey (Lucas+ 2012)II/319 : UKIDSS-DR9 LAS, GCS and DXS Surveys (Lawrence+ 2012)II/328 : AllWISE Data Release (Cutri+ 2013)VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)II/321 : IPHAS DR2 Source Catalogue (Barentsen+, 2014)II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/ApJS/91/659 : Ultracompact HII regions radio images (Kurtz+ 1994)J/ApJ/675/491 : Lynds 988e JHKs and IRAC photometry (Allen+, 2008)J/ApJ/682/445 : Spitzer observations of S254-S258 (Chavarria+, 2008)J/ApJ/674/336 : Spitzer observations of NGC 1333 (Gutermuth+, 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/720/679 : Optical spectroscopy in Cygnus X region (Beerer+, 2010)J/ApJ/712/797 : YSOs in Vul OB1 association (Billot+, 2010)J/MNRAS/415/103 : IPHAS T Tauri candidates in IC 1396 (Barentsen+, 2011)J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)J/MNRAS/432/3445 : YSOs on HII complex Sh2-252 (Jose+, 2013)J/ApJS/205/1 : CORNISH project. II. Source catalog (Purcell+, 2013)J/A+A/561/A83 : SDC13 infrared dark clouds spectra (Peretto+, 2014)J/MNRAS/454/4335 : Multiwavelength photometry of Sh 2-138 YSOs (Baug+, 2015)J/ApJ/836/98 : YSOs search in Stock 8 with opt. to IR photom. (Jose+, 2017)J/MNRAS/468/2684 : IC1805 YSOs (Panwar+, 2017)J/A+A/642/A87 : Hub-filament candidates (Kumar+, 2020)J/AJ/159/153 : Optical & IR phot. in the HII region Sh2-242 (Panja+, 2020)J/ApJ/939/46 : Stellar contents in the Sh2-112 cloud complex (Panja+, 2022)http://www.cadc-ccda.hia-iha.nrc-cnrc.gc.ca/en/jcmt/ : JCMT archive homepagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/961/176https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/961/176http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/961/176https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/961/176https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/961/176http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/961/176GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/961/176/table1 (Photometric catalog of YSOs toward Sh2-87)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/176/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/176/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/176/table1?GETtext/xml+votable180.050000true296.7297724.6658130.005555555555555556Cone search capability for table J/ApJ/961/176/table2 (Photometric catalog of H{alpha} emitters toward Sh2-87)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/961/176/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/961/176/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/961/176/table2?GETtext/xml+votable180.050000true296.4894524.629320.0055555555555555566/14356 14358-143592.0616683193919197e-20 4.670716440110116e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/961/176?format=asciiOpticalInfrareddefaultJ/ApJ/961/176/table1Photometric catalog of YSOs toward Sh2-87ClassClass identifier (II: 202 occurrences; I: 13 occurrences)src.classcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/202] Serial numbermeta.id;meta.mainintRAJ2000[296.4/296.8] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[24.4/24.8] Declination (J2000)degpos.eq.dec;meta.main3.6mag[8.6/14.5]? Spitzer/IRAC 3.6um band apparent magnitudemagphot.mag;em.IR.3-4umfloatnullablee_3.6mag[0.003/0.3]? Uncertainty in 3.6magmagstat.error;phot.mag;em.IR.3-4umfloatnullable4.5mag[8.2/14.13]? Spitzer/IRAC 4.5um band apparent magnitudemagphot.mag;em.IR.4-8umfloatnullablee_4.5mag[0.03/0.4]? Uncertainty in 4.5magmagstat.error;phot.mag;em.IR.4-8umfloatnullable5.8mag[7.7/13.01]? Spitzer/IRAC 5.8um band apparent magnitudemagphot.mag;em.IR.4-8umfloatnullablee_5.8mag[0.02/0.4]? Uncertainty in 5.8magmagstat.error;phot.mag;em.IR.4-8umfloatnullable8.0mag[0/12.6]? Spitzer/IRAC 8.0um band apparent magnitudemagphot.mag;em.IR.8-15umfloatnullablee_8.0mag[0/0.4]? Uncertainty in 8.0magmagstat.error;phot.mag;em.IR.8-15umfloatnullableJmag[11.6/19.9]? UKIDSS J band apparent magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag[0/0.3]? Uncertainty in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag[11.2/18.4]? UKIDSS H band apparent magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag[0/0.2]? Uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKmag[9.98/17.6]? UKIDSS K band apparent magnitudemagphot.mag;em.IR.Kfloatnullablee_Kmag[0/0.2]? Uncertainty in Kmagmagstat.error;phot.mag;em.IR.KfloatnullableGPS6Display data from UKIDSS-DR6 (II/316) within 3"meta.ref.urlchargmag[14.6/26.5]? PANSTARRS g band apparent magnitudemagphot.mag;em.opt.Bdoublenullablee_gmag[0/0.5]? Uncertainty in gmagmagstat.error;phot.mag;em.opt.Bdoublenullableymag[12.89/19.74]? PANSTARRS y band apparent magnitudemagphot.mag;em.IR.Jdoublenullablee_ymag[0.002/0.3]? Uncertainty in ymagmagstat.error;phot.mag;em.IR.JdoublenullablePS1Display data from PS1 DR1 (II/349) and PS1 DR2 (II/389) within 1"meta.ref.urlcharDist[1.1/6.3]? Estimated Gaia EDR3 photogeometric distancekpcpos.distancefloatnullablee_Dist[0.045/2.8]? Lower uncertainty in Distkpcstat.error;stat.min;pos.distancedoublenullableE_Dist[0.048/3]? Upper uncertainty in Distkpcstat.error;stat.max;pos.distancefloatnullableGaiaDisplay data from Bailer-Jones+ (I/352) within 3"meta.ref.urlcharJ/ApJ/961/176/table2Photometric catalog of H{alpha} emitters toward Sh2-87recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/22] Serial numbermeta.id;meta.mainintRAJ2000[296.41136/296.7] Right Ascension (J2000)degpos.eq.ra;meta.mainDEJ2000[24.47/24.7] Declination (J2000)degpos.eq.dec;meta.mainrmag[14.05/19.9] IPHAS r band apparent magnitudemagphot.mag;em.opt.Rfloate_rmag[0/0.07] Uncertainty in rmagmagstat.error;phot.mag;em.opt.Rfloatimag[13.38/18.52] IPHAS i band apparent magnitudemagphot.mag;em.opt.Ifloate_imag[0/0.04] Uncertainty in imagmagstat.error;phot.mag;em.opt.IfloatHamag[13.39/18.57] IPHAS H{alpha} band apparent magnitudemagphot.mag;em.line.Halphafloate_Hamag[0/0.04] Uncertainty in Hamagmagstat.error;phot.mag;em.line.HalphafloatIPHASDisplay data from IPHAS DR2 (II/321) within 3"meta.ref.urlcharJmag[11.69/16.72]? UKIDSS J band apparent magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag[0/0.02]? Uncertainty in Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag[11.29/15.91]? UKIDSS H band apparent magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag[0/0.02]? Uncertainty in Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKmag[9.98/15.51] UKIDSS K band apparent magnitudemagphot.mag;em.IR.Kfloate_Kmag[0/0.03] Uncertainty in Kmagmagstat.error;phot.mag;em.IR.KfloatGPS6Display data from UKIDSS-DR6 (II/316) within 3"meta.ref.urlchargmag[14.89/23.82]? PANSTARRS g band apparent magnitudemagphot.mag;em.opt.Bdoublenullablee_gmag[0/0.2]? Uncertainty in gmagmagstat.error;phot.mag;em.opt.Bdoublenullableymag[13.22/18.06] PANSTARRS y band apparent magnitudemagphot.mag;em.IR.Jfloate_ymag[0.004/0.15] Uncertainty in ymagmagstat.error;phot.mag;em.IR.JfloatPS1Display data from PS1 DR1 (II/349) and PS1 DR2 (II/389) within 1"meta.ref.urlcharDist[1/4.2]? Estimated Gaia EDR3 photogeometric distancekpcpos.distancefloatnullablee_Dist[0.06/1.4]? Lower uncertainty in Distkpcstat.error;stat.min;pos.distancefloatnullableE_Dist[0.08/2.2]? Upper uncertainty in Distkpcstat.error;stat.max;pos.distancefloatnullableGaiaDisplay data from Bailer-Jones+ (I/352) within 3"meta.ref.urlcharClassClass identifiersrc.classchar