J/MNRAS/484/1838ivo://CDS.VizieR/J/MNRAS/484/1838doi:10.26093/cds/vizier.74841838CDSBerlanas S.R.Wright N.J.Herrero A.Drew J.E.Lennon D.J.2024-08-19T20:16:27Z2020-09-03T14:44:51ZCDS support team

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

cds-question@unistra.frstellar-associationsvisible-astronomytrigonometric-parallaxFor the first time, we have explored the spatial substructure of the Cygnus OB2 association using parallaxes from the recent second Gaia data release. We find significant line-of-sight substructure within the association, which we quantify using a parametrized model that reproduces the observed parallax distribution. This inference approach is necessary due to the non-linearity of the parallax distance transformation and the asymmetry of the resulting probability distribution. Using a Markov Chain Monte Carlo ensemble sampler and an unbinned maximum likelihood test, we identify two different stellar groups superposed on the association. We find the main Cygnus OB2 group at ~1760pc, further away than recent estimates have envisaged, and a foreground group at ~1350pc. We also calculate individual membership probabilities and identify outliers as possible non-members of the association.2019MNRAS.484.1838Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/484/1838CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/484/1838https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/484/1838http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/484/1838https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/484/1838https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/484/1838http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/484/1838GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/484/1838/tablea1 (List of stars that have not passed the selection criteria)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/484/1838/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/484/1838/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/484/1838/tablea1?GETtext/xml+votable180.050000true308.347800341.15358420.005555555555555556Cone search capability for table J/MNRAS/484/1838/tablea2 (List of Cygnus OB2 sources used in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/484/1838/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/484/1838/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/484/1838/tablea2?GETtext/xml+votable180.050000true308.3087941.33941750.0055555555555555565/4305 6/2688 2694 14667 14670-14671 14689 14691-14694 16510 16593 16683 16777 16781 16794 16878 17168 17240 17243 17274 18056 18063 19527 19533 19573 19752 19900 29134 291681.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/484/1838?format=asciiOpticaldefaultJ/MNRAS/484/1838/tablea1List of stars that have not passed the selection criteriaSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCommon name of the starmeta.id;meta.maincharGaiaDR2Gaia DR2 source identificationmeta.idPlxParallax given by Gaia DR2 (1)maspos.parallaxfloate_PlxParallax error given by Gaia DR2masstat.error;pos.parallaxfloatGmagG magnitude given by Gaia DR2magphot.mag;em.optfloat_RAPositions from Simbad (right ascension part)degpos.eq.ra;meta.main_DEPositions from Simbad (declination part)degpos.eq.dec;meta.mainJ/MNRAS/484/1838/tablea2List of Cygnus OB2 sources used in this workSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameCommon name of the starmeta.id;meta.maincharGaiaDR2Gaia DR2 source identificationmeta.idPlxParallax given by Gaia DR2 (1)maspos.parallaxfloate_PlxParallax error given by Gaia DR2masstat.error;pos.parallaxfloatGmagG magnitude given by Gaia DR2magphot.mag;em.optfloatGroup[0/3] Membership group (2)meta.idint_RAPositions from Simbad (right ascension part)degpos.eq.ra;meta.main_DEPositions from Simbad (declination part)degpos.eq.dec;meta.main