J/MNRAS/488/1535ivo://CDS.VizieR/J/MNRAS/488/1535doi:10.26093/cds/vizier.74881535CDSPalau C.G.Miralda-Escude J.2024-08-19T20:19:27Z2023-02-02T14:41:26ZCDS support team

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

cds-question@unistra.frglobular-star-clustershalo-starsvisible-astronomytrigonometric-parallaxastrometryproper-motionstwo-color-diagramsA method to search for tidal streams and to fit their orbits based on maximum likelihood is presented and applied to the Gaia data. Tests of the method are performed showing how a simulated stream produced by tidal stripping of a star cluster is recovered when added to a simulation of the Gaia catalogue. The method can be applied to search for streams associated with known progenitors or to do blind searches in a general catalogue. As the first example, we apply the method to the globular cluster M68 and detect its clear tidal stream stretching over the whole North Galactic hemisphere, and passing within 5kpc of the Sun. This is one of the closest tidal streams to us detected so far, and is highly promising to provide new constraints on the Milky Way gravitational potential, for which we present preliminary fits finding a slightly oblate dark halo consistent with other observations. We identify the M68 tidal stream with the previously discovered Fjorm stream by Ibata et al (2019ApJ...872..152I). The tidal stream is confirmed to contain stars that are consistent with the HR-diagram of M68. We provide a list of 115 stars that are most likely to be stream members, and should be prime targets for follow-up spectroscopic studies.2019MNRAS.488.1535Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/488/1535CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/488/1535https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/488/1535http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/488/1535https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/488/1535https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/488/1535http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/488/1535GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/488/1535/tablee1 (Selected stars from GDR2 catalogue)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/488/1535/tablee1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/488/1535/tablee1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/488/1535/tablee1?GETtext/xml+votable180.050000true189.5268-26.94010.0055555555555555565/6627 6/10248 10254 10277 10289 10293-10294 10337 10344 10347-10348 10351 10361-10362 10629-10631 10633 10650 10691-10692 10694 10696 10706-10707 10710 11371 11386 11393 11396 11399 11408-11410 11412-11413 11573-11574 11603 11616-11617 11620 16040 24843 26119 26128 26130-26131 26135 26140 26184 26186 26190 26208-26209 26212 26215 26221-26222 26232-26234 26309 26498 26502 26505 26522 26545 26549-26551 26601 26605-26607 27984 27987-27988 27998-27999 28021 43543 43551 43581 437221.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/488/1535?format=asciiOpticaldefaultJ/MNRAS/488/1535/tablee1Selected stars from GDR2 catalogue_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decindexedSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/115] Internal identifiermeta.idintGaiaDR2Gaia DR2 source identifiermeta.id;meta.mainplxParallaxmaspos.parallax.trigfloatDE_ICRSDeclination (ICRS) at Ep=2015.5degpos.eq.dec;meta.mainRA_ICRSRight ascension (ICRS) at Ep=2015.5degpos.eq.ra;meta.mainpmDEProper motion in declinationmas/yrpos.pm;pos.eq.decfloatpmRAProper motion in right ascensionmas/yrpos.pm;pos.eq.rafloatBP-RPGaia DR2 BP-RP colourmagphot.color;em.opt.B;em.opt.RfloatGmagGaia DR2 G-band magnitudemagphot.mag;em.optfloatXselSelection threshold for the probability densityyr**3.deg**-2.pc**-1.mas**-3stat.fit.goodnessdouble