J/A+A/655/A26 Line list (Lim+, 2021)
Chemodynamics of metal-poor wide binaries in the Galactic halo:
Association with the Sequoia event.
Lim D., Koch-Hansen A.J., Hansen C.J., Lepine S., Marshall J.L.,
Wilkinsons M.I., Penarrubia J.
<Astron. Astrophys. 655, A26 (2021)>
=2021A&A...655A..26L 2021A&A...655A..26L (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: galaxy: halo - binaries: general - stars: abundances -
stars: kinematics and dynamics
Abstract:
Recently, an increasing number of wide binaries has been discovered.
Their chemical and dynamical properties are studied through extensive
surveys and pointed observations. However, the formation of these wide
binaries is far from clear, although several scenarios have been
suggested. In order to investigate the chemical compositions of these
systems, we analysed high-resolution spectroscopy of three wide binary
pairs belonging to the Galactic halo. In total, another three
candidates from our original sample of 11 candidates observed at
various resolutions with various instruments were refuted as co-moving
pairs because their radial velocities are significantly different.
Within our sample of wide binaries, we found homogeneity amongst the
pair components in dynamical properties (proper motion and
line-of-sight velocities) and also in chemical composition. Their
metallicities are -1.16, -1.42, and -0.79dex in [Fe/H] for each wide
binary pair, which places these stars on the metal-poor side of wide
binaries reported in the literature. In particular, the most
metal-poor pair in our sample (WB2 = HD 134439/HD 134440) shows a
lower [α/Fe] abundance ratio than Milky Way field stars, which
is a clear signature of an accreted object. We also confirmed that
this wide binary shares remarkably similar orbital properties with
stars and globular clusters associated with the Sequoia event. Thus,
it appears that the WB2 pair was formed in a dwarf galaxy environment
and subsequently dissolved into the Milky Way halo. Although the other
two wide binaries appear to arise from a different formation
mechanism, our results provide a novel opportunity for understanding
the formation of wide binaries and the assembly process of the Milky
Way.
Description:
Line list containing wavelength, species, excitation potential, and
oscillator strength, used to measure abundances.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 26 193 Line List
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 0.1nm lambda Wavelength
9- 13 A5 --- Species Ion designation
15- 19 F5.3 eV EP Excitation potential
21- 26 F6.3 [-] loggf Oscillator strength
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Acknowledgements:
Dongwook Lim, dongwook.lim(at)uni-heidelberg.de
(End) Patricia Vannier [CDS] 26-Oct-2021