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Probing the outermost radii of classical dSphs with Gaia EDR3

ORAL

Abstract

We use Gaia EDR3 data to identify stars associated with six classical dwarf spheroidals (Draco, Ursa Minor, Sextans, Carina, Fornax, Sculptor) at their outermost radii, beyond their tidal limits. For four of the star candidates selected from EDR3 astrometry (two in Sextans, one in Sculptor, and one in Draco) we find radial velocity matches, indicating that these stars are associated with their respective dwarf spheroidals (dSphs) at high probability, even though they reside beyond the King tidal limit. Many of our candidates, including stars with radial velocity confirmation, lie along the orbital track of the satellites. Follow-up spectra on all of our candidates, including possible metallicity information, will help confirm their association with their respective dSphs, and could represent the first evidence for extended stellar halos or tidal debris around these classical dSphs.

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Authors

  • Yuewen Qi

    Texas A\&M University

  • Chao Ma

    University of Texas at Arlington, Florida International University, Texas A&M University-Commerce, Texas A&M University–Commerce, University of Houston Downtown, Texas A\&M University, Carnegie Mellon University, Department of Physics, MSEC, Texas State University, Ingram School of Engineering, MSEC, Texas State University, MSEC, Texas State University, Ingram School of Engineering, Texas State University, Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, USA, Department of Electrical Engineering, The Pennsylvania State University, University Park, PA 16802, USA, Texas Tech University, Texas A&M University, University of San Francisco, University of Wuppertal, University of Illinois at Urbana-Champaign, University of Houston, University of Texas at Dallas, Mitchell Institute for Fundamental Physics and Astronomy, Texas A & M University, Center for Neutrino Physics, Department of Physics Virginia Tech, None, Department of Physics, University of Texas at Dallas, Department of Electrical Engineering, Yale University

  • Chao Ma

    University of Texas at Arlington, Florida International University, Texas A&M University-Commerce, Texas A&M University–Commerce, University of Houston Downtown, Texas A\&M University, Carnegie Mellon University, Department of Physics, MSEC, Texas State University, Ingram School of Engineering, MSEC, Texas State University, MSEC, Texas State University, Ingram School of Engineering, Texas State University, Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, USA, Department of Electrical Engineering, The Pennsylvania State University, University Park, PA 16802, USA, Texas Tech University, Texas A&M University, University of San Francisco, University of Wuppertal, University of Illinois at Urbana-Champaign, University of Houston, University of Texas at Dallas, Mitchell Institute for Fundamental Physics and Astronomy, Texas A & M University, Center for Neutrino Physics, Department of Physics Virginia Tech, None, Department of Physics, University of Texas at Dallas, Department of Electrical Engineering, Yale University

  • Chao Ma

    University of Texas at Arlington, Florida International University, Texas A&M University-Commerce, Texas A&M University–Commerce, University of Houston Downtown, Texas A\&M University, Carnegie Mellon University, Department of Physics, MSEC, Texas State University, Ingram School of Engineering, MSEC, Texas State University, MSEC, Texas State University, Ingram School of Engineering, Texas State University, Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, USA, Department of Electrical Engineering, The Pennsylvania State University, University Park, PA 16802, USA, Texas Tech University, Texas A&M University, University of San Francisco, University of Wuppertal, University of Illinois at Urbana-Champaign, University of Houston, University of Texas at Dallas, Mitchell Institute for Fundamental Physics and Astronomy, Texas A & M University, Center for Neutrino Physics, Department of Physics Virginia Tech, None, Department of Physics, University of Texas at Dallas, Department of Electrical Engineering, Yale University

  • Chao Ma

    University of Texas at Arlington, Florida International University, Texas A&M University-Commerce, Texas A&M University–Commerce, University of Houston Downtown, Texas A\&M University, Carnegie Mellon University, Department of Physics, MSEC, Texas State University, Ingram School of Engineering, MSEC, Texas State University, MSEC, Texas State University, Ingram School of Engineering, Texas State University, Department of Chemistry and Biochemistry, North Carolina Central University, Durham, NC 27707, USA, Department of Electrical Engineering, The Pennsylvania State University, University Park, PA 16802, USA, Texas Tech University, Texas A&M University, University of San Francisco, University of Wuppertal, University of Illinois at Urbana-Champaign, University of Houston, University of Texas at Dallas, Mitchell Institute for Fundamental Physics and Astronomy, Texas A & M University, Center for Neutrino Physics, Department of Physics Virginia Tech, None, Department of Physics, University of Texas at Dallas, Department of Electrical Engineering, Yale University