J/ApJ/936/160ivo://CDS.VizieR/J/ApJ/936/160doi:10.26093/cds/vizier.19360160CDSZucker C.Peek J.E.G.Loebman S.2024-11-06T20:27:16Z2024-08-09T08:01:40ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyopen-star-clustersRecent analyses of Gaia data have resulted in the identification of new stellar structures, including a new class of extended stellar filaments called stellar "strings," first proposed by Kounkel & Covey. We explore the spatial, kinematic, and chemical composition of strings to demonstrate that these newfound structures are largely inconsistent with being physical objects whose members share a common origin. Examining the 3D spatial distribution of string members, we find that the spatial dispersion around the claimed string spine does not improve in the latest Gaia DR3 data release-despite tangible gains in the signal-to-noise ratio of the parallax measurements-counter to expectations of a bona fide structure. Using the radial velocity dispersion of the strings (averaging {sigma}_V_r__=16km/s) to estimate their virial masses, we find that all strings are gravitationally unbound. Given the finding that the strings are dispersing, the reported stellar ages of the strings are typically 120x larger than their measured dispersal times. Finally, we validate prior work that stellar strings are more chemically homogeneous than their local field stars but show it is possible to obtain the same signatures of chemical homogeneity by drawing random samples of stars from spatially, temporally, and kinematically unrelated open clusters. Our results show that while some strings may be composed of real substructures, there is no consistent evidence for larger string-like connections over the sample. These results underscore the need for caution in over-interpreting the significance of these strings and their role in understanding the star formation history of the Milky Way.2022ApJ...936..160Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/936/160CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/337 : Gaia DR1 (Gaia Collaboration, 2016)I/345 : Gaia DR2 (Gaia Collaboration, 2018)I/350 : Gaia EDR3 (Gaia Collaboration, 2020)III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)J/A+A/619/A155 : Open cluster kinematics with Gaia DR2 (Soubiran+, 2018)J/AJ/158/122 : Local structure & * formation history of MW (Kounkel+, 2019)J/ApJ/870/32 : Kinematics young star clusters & associations (Kuhn+, 2019)J/A+A/621/L3 : Hyades tidal tails with Gaia DR2 (Meingast+, 2019)J/A+A/622/L13 : Stellar stream in Gaia DR2 discovery (Meingast+, 2019)J/A+A/635/A45 : 570 open clusters in Galactic disc (Castro-Ginard+, 2020)J/MNRAS/496/2422 : Abundances 42 Pisces-Eridanus stream stars (Hawkins+, 2020)J/AJ/160/279 : Untangling Galaxy II. Structure within 3kpc (Kounkel+, 2020)J/A+A/639/A64 : Extended Meingast 1 source catalogue (Ratzenboeck+, 2020)J/ApJ/904/196 : Stellar parameters of a Young Stellar Snake (Tian, 2020)J/MNRAS/506/150 : The GALAH+ Survey DR3 (Buder+, 2021)J/A+A/645/A84 : Coronae of nearby star clusters (Meingast+, 2021)J/MNRAS/503/3279 : GALAH survey Galactic disc with open clusters (Spina+, 2021)J/A+A/647/A19 : 3D Kinematics and age of OCs (Tarricq+, 2021)J/AJ/163/275 : Theia 456 stellar stream in Milky Way disk (Andrews+, 2022)J/ApJ/928/70 : Gaia EDR3 members stars of 55 FoF groups (Coronado+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/936/160https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/936/160http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/936/160https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/936/160https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/936/160http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/936/160GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/936/160/table2 (Spatial and dynamical properties of stellar strings)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/936/160/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/936/160/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/936/160/table2?GETtext/xml+votable180.050000true324.74557.5140.0055555555555555560/https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/936/160?format=asciidefaultJ/ApJ/936/160/table2Spatial and dynamical properties of stellar stringsTheia[9/1640] Name of the string (1)meta.id;meta.mainintOffset-DR2[4/94] Median Gaia DR2 distance offset between stars and spinepcpos.distance;instr.offsetintSNR-DR2[15/221] Median signal-to-noise, Gaia DR2 parallax measurementsstat.snrintOffset-DR3[4/107] Median Gaia DR3 distance offset between stars and spinepcpos.distance;instr.offsetintSNR-DR3[18/478] Median signal-to-noise, Gaia DR3 parallax measurementsstat.snrintsigma-Vr[3.0/53.2] Error-weighted radial velocity dispersion (2)km/sstat.error;spect.dopplerVelocfloatMvir[45000/52000000] Predicted virial mass of string using sigma-VrsolMassphys.massfloatMobs[19/6457] Estimated observed mass of string (3)solMassphys.massintMvir/MobsRatio, predicted virial to observed mass of stringphys.mass;arith.ratiochartdisp[0.2/12.6] Predicted dispersal time of unbound string (4)Myrtime.epochfloatAge[4/8969] Reported string age (5)Myrtime.ageintAge/tdisp[3/7885] Ratio, reported age to dispersal timetime.epochintSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPosition from Simbad (right ascension part)degpos.eq.ra;meta.main_DEPosition from Simbad (declination part)degpos.eq.dec;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint