{"paper":{"title":"High-resolution spectroscopy of the GD-1 stellar stream localizes the perturber near the orbital plane of Sagittarius","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.SR","hep-ph"],"primary_cat":"astro-ph.GA","authors_text":"Adrian M. Price-Whelan, Ana Bonaca, Benjamin D. Johnson, Charlie Conroy, David W. Hogg, Joshua S. Speagle, Nelson Caldwell, Phillip A. Cargile, Rohan P. Naidu","submitted_at":"2020-01-20T19:00:02Z","abstract_excerpt":"The $100^\\circ$-long thin stellar stream in the Milky Way halo, GD-1, has an ensemble of features that may be due to dynamical interactions. Using high-resolution MMT/Hectochelle spectroscopy we show that a spur of GD-1-like stars outside of the main stream are kinematically and chemically consistent with the main stream. In the spur, as in the main stream, GD-1 has a low intrinsic radial velocity dispersion, $\\sigma_{V_r}\\lesssim1\\,\\rm km\\,s^{-1}$, is metal-poor, $\\rm [Fe/H]\\approx-2.3$, with little $\\rm [Fe/H]$ spread and some variation in $\\rm [\\alpha/Fe]$ abundances, which point to a commo"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2001.07215","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2001.07215/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}