J/A+A/622/L13ivo://CDS.VizieR/J/A+A/622/L13doi:10.26093/cds/vizier.36229013CDSMeingast S.Alves J.Fuernkranz V.2020-06-25T14:46:39Z2019-02-15T08:24:21ZCDS support team

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

cds-question@unistra.frastrometryWe report the discovery of a large, dynamically cold, coeval stellar stream that is currently traversing the immediate solar neighborhood at a distance of only 100pc. The structure was identified in a wavelet decomposition of the 3D velocity space of all stars within 300pc of the Sun. Its members form a highly elongated structure with a length of at least 400pc, while its vertical extent measures only about 50pc. Stars in the stream are not isotropically distributed but instead form two parallel lanes with individual local overdensities, that may correspond to a remnant core of a tidally disrupted cluster or OB association. Its members follow a very well-defined main sequence in the observational Hertzsprung-Russel diagram and also show a remarkably low 3D velocity dispersion of only 1.3km/s. These findings strongly suggest a common origin as a single coeval stellar population. An extrapolation of the present-day mass function indicates a total mass of at least 2000M_{sun}_, making it larger than most currently known clusters or associations in the solar neighborhood. We estimated the age of the stream to be around 1 Gyr based on a comparison with a set of isochrones and giant stars in our member selection and find a mean metallicity of [Fe/H]=-0.04. This structure may very well represent the Galactic disk counterpart to the prominent stellar streams observed in the Milky Way halo. As such, it constitutes a new valuable probe to constrain the Galaxy's mass distribution.2019A&A...622L..13Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/622/L13CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+A/621/L3 : Hyades tidal tails with Gaia DR2 (Meingast+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/622/L13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/622/L13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/622/L13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/622/L13https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/622/L13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/622/L13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/622/L13/stream (Stream selection)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/622/L13/stream?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/622/L13/stream?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/622/L13/stream?GETtext/xml+votable180.050000true356.25467562-31.530669310.0055555555555555566/52 175 12623 16530 16602 16626 16670 16691 16736 16759 16984 16988-16989 17009 17068 17092 17117 17145 17172 17185 17216 17259 17266 17292 17338 17359 17397 17407 17437 17457 17497 17607 17626 17656 17670 17679-17680 17683-17684 17691 17701 17703 17705 17713 17715 17733-17734 17736 17827 17859 17870 17883 17965 17968 17987 17989 18003 18049 18064 18072-18073 18077 18079 18089 18091 18093 18103-18104 18127 18132 18136 18147 18201 18282 18312 18376 18407 18438 18448 18504 18511 18559 18609 18641-18642 18655 18675 18689 18753 18769 18782 18809 18811 18824 18848 18876 18895 18898 18932 19005 19059 19199 19235 19241 19243 19249 19270 19272-19273 19301 19334 19336 19361 19381 19410 19438-19439 19461 19465 19477 19480 19489 19493 19505 19507 19555 19564 19593 19595 19617 19629 19696 19843 19878 19891 19894 19978 20000 20226 20288 21094 21104 21158 21172 21187 21189 21195-21196 21198 21213 21224 21229 21231 21237 21245 21386 21411 22532 22542 22566 22580 22592 22635 22639 22648 22667 22676 22685 22691 22707 22713 22720-22721 22724 22728 22730 22736 22763 22771 22776 22786 22790 23047 23058 23060 23074 23099 23116 23140 23213 23280 34334 34387 34410 34423 34556 34610 35351 35390-35391 35414 35421 35644 35736 35853 36012 36031 36109 36118 36135 36137 36184 36199 36215 36218 36245 36261 36269 36285 36336 36340 36342 36358 36371 36392 36444 36449 36517 36532 36576 36588 36629 36660 36671 36684 36696 36725 36787 36799 36805 36816 36821 470951.9867573869263685e-19 4.851276835901009e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/622/L13?format=asciidefaultJ/A+A/622/L13/streamStream selectionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDR2NameGaia DR2 Unique source designation, Gaia DR2 NNNNNNNNNNNNNNNNNNN (designation)meta.idcharSourceGaia DR2 Unique source identifier (source_id)meta.id;meta.mainRA_ICRSGaia DR2 Right ascension (ICRS) at Ep=2015.5 (ra)degpos.eq.ra;meta.mainDE_ICRSGaia DR2 Declination (ICRS) at Ep=2015.5 (dec)degpos.eq.dec;meta.mainPlxGaia DR2 Parallax (parallax)maspos.parallaxdoublee_PlxGaia DR2 Standard error of parallax (parallax_error)masstat.error;pos.parallaxdoublepmRAGaia DR2 Proper motion in ra direction (pmra)mas/yrpos.pm;pos.eq.radoublee_pmRAGaia DR2 Standard error of proper motion in ra direction (pmra_error)mas/yrstat.error;pos.pm;pos.eq.radoublepmDEGaia DR2 Proper motion in dec direction (pmdec)mas/yrpos.pm;pos.eq.decdoublee_pmDEGaia DR2 Standard error of proper motion in dec direction (pmdec_error)mas/yrstat.error;pos.pm;pos.eq.decdoubleamaxGaia DR2 The longest semi-major axis of the 5-d error ellipsoid (astrometric_sigma5d_max)maspos.errorEllipse;stat.maxdoubleGmagGaia DR2 G-band mean magnitude (phot_g_mean_mag)magphot.mag;em.optfloatBPmagGaia DR2 Integrated BP mean magnitude (phot_bp_mean_mag)magphot.mag;em.opt.BfloatRPmagGaia DR2 Integrated RP mean magnitude (phot_rp_mean_mag)magphot.mag;em.opt.RfloatRVGaia DR2 Radial velocity (radial_velocity)km/sphys.veloc;pos.heliocentricdoublee_RVGaia DR2 Radial velocity error (radial_velocity_error)km/sstat.errordoubleXGalactic Cartesian X (X)pcpos.cartesian.x;pos.galacticdoubleYGalactic Cartesian Y (Y)pcpos.cartesian.y;pos.galacticdoubleZGalactic Cartesian Z (Z)pcsrc.redshift;pos.galactic;pos.cartesiandoublegcRGalactocentric Cylindrical R (gc_R)pcpos.distance;pos.galactocentricdoublegcPHIGalactocentric Cylindrical PHI (gc_PHI)pcpos.distance;pos.galactocentricdoublegcZGalactocentric Cylindrical Z (gc_Z)pcpos.distance;pos.galactocentricdoublegcvRGalactocentric Cylindrical vR (gc_vR)km/sphys.veloc;pos.galactocentricfloatgcvPHIGalactocentric Cylindrical vPHI (gc_vPHI)km/sphys.veloc;pos.galactocentricfloatgcvZGalactocentric Cylindrical vZ (gc_vZ)km/sphys.veloc;pos.galactocentricfloatSimbadSimbad column added by the CDSmeta.ref.urlchar_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.decnullableindexed