J/AZh/95/54 Galactic-field RR Lyrae abundances and kinematics (Marsakov+ 2018)
Relationship between the elemental abundances and the kinematics of
Galactic-field RR Lyrae stars.
Marsakov V.A., Gozha M.L., Koval V.V.
<Astron. Zh. 95, 54 (2018)>
=2018ARep...62...50M 2018ARep...62...50M
=2018AZh....95...54M 2018AZh....95...54M (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, variable ; Abundances ; Space velocities ;
Radial velocities
Keywords: RR Lyrae stars - chemical composition - kinematics -
Galaxy (Milky Way)
Abstract:
Data of our compiled catalog containing the positions, velocities, and
metallicities of 415 RR Lyrae variable stars and the relative
abundances [el/Fe] of 12 elements for 101 RR Lyrae stars, including
four α elements (Mg, Ca, Si, and Ti), are used to study the
relationships between the chemical and spatial-kinematic properties
of these stars. In general, the dependences of the relative abundances
of α elements on metallicity and velocity for the RR Lyrae stars are
approximately the same as those for field dwarfs. Despite the usual
claim that these stars are old, among them are representatives of the
thin disk, which is the youngest subsystem of the Galaxy. Attention is
called to the problem of low metallicity RR Lyrae stars. Most RR Lyrae
stars that have the kinematic properties of thick disk stars have
metallicities [Fe/H]←1.0 and high ratios [α/Fe]~=0.4, whereas
only about 10% of field dwarfs belonging to the so-called
"low-metallicity tail" have this chemical composition. At the same
time, there is a sharp change in [α/Fe] in RR Lyrae stars belonging
just to the thick disk, providing evidence for a long period of
formation of this subsystem. The chemical compositions of
SDSS J1707+58, V455 Oph, MACHO176.18833.411, V456 Ser, and
BPS CS 30339-046 do not correspond to their kinematics. While the
first three of these stars belong to the halo, according to their
kinematics, the last two belong to the thick disk. It is proposed that
they are all most likely extragalactic, but the possible appearance of
some of them in the solar neighborhood as a result of the
gravitational action of the bar on field stars cannot be ruled out.
Description:
Data of compiled catalog containing the positions, velocities, and
metallicities of 415 RR Lyrae variable stars and the relative
abundances [el/Fe] of 12 elements for 100 RR Lyrae stars, including
four alpha-elements (Mg, Ca, Si, and Ti), are used to study the
relationships between the chemical and spatial-kinematic properties of
these stars
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 249 415 The catalog data for 415 RR Lyrae stars
refs.dat 76 31 References
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Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 24 A24 --- Star Star name
26- 33 F8.4 deg GLON Galactic longitude
35- 42 F8.4 deg GLAT Galactic latitude
44- 49 F6.4 d PF Fundamental period of pulsations
51- 56 F6.3 kpc d ? Heliocentric distance
58- 64 F7.3 kpc x ? Heliocentric distance towards Galactic center
66- 71 F6.3 kpc y ? Heliocentric distance towards Galactic
rotation
73- 78 F6.3 kpc z ? Heliocentric distance towards North Galactic
Pole
80- 85 F6.3 kpc RG ? Galactocentric distance
87- 92 F6.1 km/s ULSR ? U velocity component in the LSR
94- 99 F6.1 km/s VLSR ? V velocity component in the LSR
101-106 F6.1 km/s WLSR ? W velocity component in the LSR
108-113 F6.1 km/s VR ? Galactocentric cylindrical velocity
component towards Galactic anticenter
115-120 F6.1 km/s Vtheta ? Galactocentric cylindrical velocity
component towards Galactic rotation
122-127 F6.1 km/s VZ ? Galactocentric cylindrical velocity
component towards N. Galactic Pole
129-137 A9 --- Ref1 References for d and RV in refs.dat file
139-143 F5.2 [Sun] [Fe/H]D ? Metallicity from Dambis et al.
(2013MNRAS.435.3206D 2013MNRAS.435.3206D)
145-149 F5.2 [Sun] [Fe/H] ? Abundance [Fe/H]
151-155 F5.2 [Sun] [O/Fe] ? Abundance [O/Fe]
157-161 F5.2 [Sun] [Na/Fe] ? Abundance [Na/Fe]
163-167 F5.2 [Sun] [Mg/Fe] ? Abundance [Mg/Fe]
169-173 F5.2 [Sun] [Al/Fe] ? Abundance [Al/Fe]
175-179 F5.2 [Sun] [Si/Fe] ? Abundance [Si/Fe]
181-185 F5.2 [Sun] [Ca/Fe] ? Abundance [Ca/Fe]
187-191 F5.2 [Sun] [Ti/Fe] ? Abundance [Ti/Fe]
193-197 F5.2 [Sun] [Y/Fe] ? Abundance [Y/Fe]
199-202 F4.2 [Sun] [Zr/Fe] ? Abundance [Zr/Fe]
204-208 F5.2 [Sun] [Ba/Fe] ? Abundance [Ba/Fe]
210-214 F5.2 [Sun] [La/Fe] ? Abundance [La/Fe]
216-220 F5.2 [Sun] [Eu/Fe] ? Abundance [Eu/Fe]
222-249 A28 --- Ref2 References for abundances, in refs.dat file
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref [1/31] Reference number
4- 22 A19 --- BibCode BibCode
24- 42 A19 --- Aut Autor's name
44- 76 A33 --- Com Comments
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Acknowledgements:
Marina Gozha, gozha_marina(at)mail.ru
Vladimir Marsakov, marsakov(at)sfedu.ru
(End) Marina Gozha [SFedU, Russia], Patricia Vannier [CDS] 03-Dec-2018