Published May 1, 2020 | Version v1
Journal article Metadata-only

Two Substructures in the nearby Stellar Halo Found in Gaia and RAVE

Creators

  • 1. School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China)
  • 2. College of Astronomy and Space Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China)
  • 3. GEPI, Observatoire de Paris, PSL Research University, CNRS, Place Jules Janssen, F-92190 Meudon (France)
  • 4. Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States)

Description

We use the second Gaia data release (Gaia DR2), combined with Radial Velocity Experiment spectroscopic surveys, to identify the substructures in the nearby stellar halo. We select 3845 halo stars kinematically and chemically and determine their density distribution in energy and angular momentum space. To select the substructures from overdensities, we reshuffle the velocities and estimate their significance. Two statistically significant substructures, GR-1 and GR-2, are identified. GR-1 has a high binding energy and small z-angular momentum. GR-2 is metal-rich but retrograde. They are both new substructures, and may be accretion debris of dwarf galaxies.

Availability note (English)

Available from http://dx.doi.org/10.3847/1538-4357/ab8733

Additional details

Identifiers

DOI
10.3847/1538-4357/ab8733;

Publishing Information

Journal Title
Astrophysical Journal
Journal Volume
895
Journal Issue
1
Journal Page Range
[10 p.]
ISSN
0004-637X
CODEN
ASJOAB

INIS

Country of Publication
United Kingdom
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
52065086
Subject category
S79: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY;
Descriptors DEI
ANGULAR MOMENTUM; BINDING ENERGY; DENSITY; DISTRIBUTION; GALAXIES; METALS; RADIAL VELOCITY; SPACE; STARS
Descriptors DEC
ELEMENTS; ENERGY; PHYSICAL PROPERTIES; VELOCITY