{"paper":{"title":"Farthest Neighbor: The Distant Milky Way Satellite Eridanus II","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO"],"primary_cat":"astro-ph.GA","authors_text":"A. A. Plazas, A. Benoit-L\\'evy, A. B. Pace, A. Carnero Rosell, A. Drlica-Wagner, A. K. Romer, A. R. Walker, B. Flaugher, B. Santiago, B. Yanny, C. B. D'Andrea, C. E. Cunha, D. A. Goldstein, D. Brooks, D. Gruen, D. J. James, D. L. Burke, D. L. DePoy, D. L. Tucker, D. Thomas, E. Balbinot, E. Bertin, E. Krause, E. Sanchez, E. Suchyta, F. Menanteau, F. Sobreira, G. Gutierrez, G. M. Bernstein, G. Tarle, H. Lin, H. T. Diehl, I. Sevilla-Noarbe, J. Carretero, J. D. Simon, J. Frieman, J. Garc\\'ia-Bellido, J. Gschwend, J. L. Marshall, K. Bechtol, K. Kuehn, L. N. da Costa, L. Strigari, M. A. G. Maia, M. Carrasco Kind, M. March, M. Schubnell, M. Y. Wang, R. A. Gruendl, R. C. Smith, R. H. Wechsler, R. Miquel, S. Allam, S. Desai, T. F. Eifler, T. M. C. Abbott, T. S. Li, W. Wester, Y. Zhang","submitted_at":"2016-11-15T21:03:55Z","abstract_excerpt":"We present Magellan/IMACS spectroscopy of the recently-discovered Milky Way satellite Eridanus II (Eri II). We identify 28 member stars in Eri II, from which we measure a systemic radial velocity of $v_{\\rm hel} = 75.6 \\pm 1.3~\\mbox{(stat.)} \\pm 2.0~\\mbox{(sys.)}~\\mathrm{km\\,s^{-1}}$ and a velocity dispersion of $6.9^{+1.2}_{-0.9}~\\mathrm{km\\,s^{-1}}$. Assuming that Eri~II is a dispersion-supported system in dynamical equilibrium, we derive a mass within the half-light radius of Eri II is $1.2^{+0.4}_{-0.3} \\times 10^{7}~\\mathrm{M_\\odot}$, indicating a mass-to-light ratio of $420^{+210}_{-140}"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1611.05052","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}