The Draco Dwarf Spheroidal Galaxy in the First Year of Dark Energy Spectroscopic Instrument Data
Year: 2025
Type: article
Abstract: We investigate the spatial distribution, kinematics, and metallicity of stars in the Draco dwarf spheroidal galaxy using data from the Dark Energy Spectroscopic Instrument (DESI). We identify 155 high-probability members of Draco using line-of-sight velocity and metallicity information derived from DESI spectroscopy along with Gaia Data Release 3 proper motions. We find a mean line-of-sight velocity of −290.62 ± 0.80 km s −1 with dispersion = 9.5 7 − 0.62 + 0.66 km s −1 and mean metallicity [Fe/H] = −2.10 ± 0.04, consistent with previous results. We also find that Draco has a steep metallicity gradient within the half-light radius, and a metallicity gradient that flattens beyond the half-light radius. We identify eight high-probability members outside the King tidal radius, four of which we identify for the first time. These extratidal stars are not preferentially aligned along the orbit of Draco. We compute an average surface brightness of 34.02 mag arcsec − 2 within an elliptical annulus from the King tidal radius of 48 . ′ 1–81′.
Source: The Astrophysical Journal
Authors: J. Ding, C. Rockosi, Ting S. Li, S. E. Koposov, A. H. Riley, W. Wang, A. P. Cooper, N. Kizhuprakkat, M. Lambert, G. E. Medina, N. Sandford, J. Aguilar, S. Ahlen, D. Bianchi, D. Brooks, T. Claybaugh, A. de la Macorra, P. Doel, J. E. Forero-Romero, E. Gaztañaga, S. Gontcho A Gontcho, G. Gutierrez, J. Guy, M. Ishak, R. Kehoe, T. Kisner, A. Kremin, O. Lahav, M. Landriau, L. Le Guillou, A. Meisner, R. Miquel, J. Moustakas, F. Prada, I. Pérez-Ràfols, G. Rossi, E. Sanchez, M. Schubnell, J. Silber, D. Sprayberry, G. Tarlé, B. A. Weaver, R. Zhou
Institutions: University of Arizona, University of California, Santa Cruz, University of Toronto, University of Cambridge, Royal Observatory, University of Edinburgh, Durham University, Shanghai Jiao Tong University, National Tsing Hua University, Lawrence Berkeley National Laboratory, Boston University, University of Milan, Brera Astronomical Observatory, University College London, Universidad Nacional Autónoma de México, Universidad de Los Andes, University of Portsmouth, Fermi National Accelerator Laboratory, The University of Texas at Dallas, Southern Methodist University, Centre National de la Recherche Scientifique, Sorbonne Université, Laboratoire de Physique Nucléaire et de Hautes Énergies, Institut National de Physique Nucléaire et de Physique des Particules, NSF NOIRLab, Institució Catalana de Recerca i Estudis Avançats, Siena College, Instituto de Astrofísica de Andalucía, Universitat Politècnica de Catalunya, Sejong University, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, University of Michigan
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science and Technology Council, National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, Ministerio de Ciencia, Innovación y Universidades, Ministry of Education, India, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, National Science and Technology Council, Office of Science, Natural Sciences and Engineering Research Council of Canada, Science and Technology Facilities Council, Agencia Estatal de Investigación, Division of Astronomical Sciences, High Energy Physics
Awards: G1044631029, G1105844351, G1175115578, G1286236842, G1379692010, G1813527838, G1863003419, PROPOSAL TO EXPLORE THE FUNDAMENTAL CONSTITUENTS OF THE UNIVERSE FUNDING YEARS FY 2018-2020, G1921377837, G2262748287, G2550080368, G2614460161, G2857234098, G294895050, G300979063, G3083819904, G3452655474, G3480869486, RESEARCH IN PARTICLE PHYSICS, G4061288673, G419881185, G425668148, G42916606, G4501827968, G491712853, G4976382292, G498139845, G5080475149, G5635532810, G593054264, G6652958823, IMPLEMENTING, INTEGRATING AND APPLYING CODES AND METHODS FOR DARK ENERGY PARAMETER CONSTRAINT ANALYSIS INCLUDING INTRINSIC ALIGNMENT SYSTEMATIC MITIGATION FOR DARK ENERGY SURVEYS, G6876926712, Probing dark matter distribution in the Milky Way with the DESI survey, Management and Operations of the National Optical Astronomy Observatory, G7395345766, G759921648, G7805626310, G7863371703, G8497050386, Near Field Cosmology with Milky Way's Satellite Galaxies and Stellar Streams, G8667377315, RESEARCH IN PARTICLE PHYSICS, G969889393
OpenAlex ID: W4416384673