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Title: KINEMATICS OF CLASSICAL CEPHEIDS IN THE NUCLEAR STELLAR DISK

Classical Cepheids are useful tracers of the Galactic young stellar population because their distances and ages can be determined from their period-luminosity and period-age relations. In addition, the radial velocities and chemical abundance of the Cepheids can be derived from spectroscopic observations, providing further insights into the structure and evolution of the Galaxy. Here, we report the radial velocities of classical Cepheids near the Galactic center, three of which were reported in 2011 and a fourth being reported for the first time. The velocities of these Cepheids suggest that the stars orbit within the nuclear stellar disk, a group of stars and interstellar matter occupying a region of ∼200 pc around the center, although the three-dimensional velocities cannot be determined until the proper motions are known. According to our simulation, these four Cepheids formed within the nuclear stellar disk like younger stars and stellar clusters therein.
Authors:
;  [1] ; ; ;  [2] ;  [3] ; ;  [4] ;  [5] ; ; ;  [6] ; ;  [7] ;  [8] ;  [9]
  1. Department of Astronomy, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
  2. Institute of Astronomy, School of Science, The University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)
  3. European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany)
  4. Dipartimento di Fisica, Universitá di Roma Tor Vergata, Via della Ricerca Scientifica 1, I-00133 Rome (Italy)
  5. Earth-Life Science Institute, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)
  6. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)
  7. Koyama Astronomical Observatory, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan)
  8. Miyagi University of Education, 149 Aramaki-aza-Aoba, Aoba-ku, Sendai, Miyagi 980-0845 (Japan)
  9. Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan)
Publication Date:
OSTI Identifier:
22364535
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 799; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CEPHEIDS; COMPUTERIZED SIMULATION; DISTANCE; GALACTIC EVOLUTION; GALAXIES; LUMINOSITY; MILKY WAY; ORBITS; PROPER MOTION; RADIAL VELOCITY; STAR CLUSTERS; THREE-DIMENSIONAL CALCULATIONS