2019
On the Oosterhoff dichotomy in the Galactic bulge - II. Kinematical distribution
PRUDIL, Zdeněk; Istvan DEKANY; E. K. GREBEL; Marcio CATELAN; Marek SKARKA et. al.Basic information
Original name
On the Oosterhoff dichotomy in the Galactic bulge - II. Kinematical distribution
Authors
PRUDIL, Zdeněk (203 Czech Republic, guarantor); Istvan DEKANY; E. K. GREBEL; Marcio CATELAN; Marek SKARKA (203 Czech Republic, belonging to the institution) and R. SMOLEC
Edition
Monthly Notices of the Royal Astronomical Society, Oxford, OXFORD UNIV PRESS, 2019, 0035-8711
Other information
Language
English
Type of outcome
Article in a journal
Field of Study
10308 Astronomy
Country of publisher
United Kingdom of Great Britain and Northern Ireland
Confidentiality degree
is not subject to a state or trade secret
References:
Impact factor
Impact factor: 5.357
RIV identification code
RIV/00216224:14310/19:00111910
Organization unit
Faculty of Science
UT WoS
000478053200024
EID Scopus
2-s2.0-85072277662
Keywords in English
stars: variables: RR Lyrae; Galaxy: bulge; Galaxy: kinematics and dynamics
Tags
Tags
International impact, Reviewed
Changed: 10/3/2020 10:28, Mgr. Marie Novosadová Šípková, DiS.
Abstract
V originále
We present a kinematical study of RR Lyrae stars associated with two Oosterhoff groups in the Galactic bulge, We used data published in the first paper of the series, plus proper motions from the Gaia Data Release 2, and radial velocities from the literature, A 6D kinematical and spatial solution was obtained for 429 RR Lyrae stars, We use a model of the Galactic gravitational potential to infer stellar orbits. We did not find a difference between the Oosterhoff groups in the individual components of the space velocity. We report that foreground and background stars with respect to the Galactic bulge stand out in the mean V velocity component, which we interpret as a sign of the Galactic rotation. The movement of the studied stars in the central region of the Galactic bulge is consistent with random motions expected for a classical bulge component. From the orbital integration, we estimate that 8 per cent of the RR Lyrae stars are halo interlopers currently located in the Galactic bulge. The majority of the stars' orbits are within a 3 kpc radius from the Galactic bulge. The fraction of Oosterhoff II stars increases with increasing Galactic latitude, as well as towards longer orbital periods. We found several RR Lyrae stars with high space velocities, one of which has an extremely long orbital period of similar to 1 Gyr. We conclude that based on their kinematics, the vast majority of the stars in our sample do not seem to contribute to the boxy/peanut component of the Galactic bulge.
Links
EF16_027/0008360, research and development project |
|