J/A+A/690/A120 Metal-poor accreted star cand. abund. (De Brito Silva+, 2024)
The accreted galaxy: An overview of TESS metal-poor accreted star candidates.
De Brito Silva D., Jofre P., Worley C., Hawkins K., Das P.
<Astron. Astrophys. 690, A120 (2024)>
=2024A&A...690A.120D 2024A&A...690A.120D (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, metal-deficient ; Abundances ; Optical
Keywords: stars: abundances - Galaxy: halo - Galaxy: stellar content
Abstract:
The Milky Way is a mosaic of stars from different origins. In
particular, metal-poor accreted star candidates offer a unique
opportunity to better understand the accretion history of the Milky
Way. In this work, we aim to explore the assembly history of the Milky
Way by investigating accreted stars in terms of their ages, dynamical
properties, and chemical abundances. We also aim to better
characterize the impact of incorporating asteroseismic information on
age and chemical abundance calculations of metal-poor accreted stars
for which TESS data are available. In this study, we conducted an
in-depth examination of 30 metal-poor accreted star candidates using
TESS and Gaia data as well as MIKE spectra. We find satisfactory
agreement between seismic surface gravity (logg) values and values
obtained using spectroscopy, demonstrating the reliability of
spectroscopic data produced by our methodology. We find that while age
determination is highly dependent on the log g and asteroseismic
information used, the overall chemical abundance distributions are
similar for different logg. However, we find that calcium (Ca)
abundances are more sensitive to the adopted logg. Our study reveals
that the majority of our stars have properties that are compatible
with those reported for the Gaia-Sausage-Enceladus, with a minority of
stars that might be associated with Splash. We find an age
distribution with a median of 11.3Gyr when including asteroseismic
information. Regarding some key chemical signatures, we note that
these stars are metal poor ([Fe/H])←0.8), α rich
([α]/Fe]>0.2), and copper poor ([Cu/Fe]<0 ), with chemical
abundances typical of accreted stars. These findings illustrate the
importance of multidimensional analyses in unraveling the complex
accretion history of the Milky Way.
Description:
Chemical abundances shown in Figure 8 for the stars analyzed in this
study.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
figure8.dat 284 29 Chemical abundances shown in Figure 8 for the
stars analyzed in this study
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: figure8.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source_id
21- 23 I3 --- ID Identification number
25- 31 F7.4 --- [Fe/H] Abundance [Fe/H]
33- 39 F7.4 --- [Mg/Fe] Abundance [Mg/Fe]
41- 49 F9.4 --- [Si/Fe] Abundance [Si/Fe]
51- 57 F7.4 --- [Ca/Fe] Abundance [Ca/Fe]
59- 64 F6.4 --- [Ti/Fe] Abundance [Ti/Fe]
66- 74 E9.1 --- [Cr/Fe] Abundance [Cr/Fe]
76- 84 F9.4 --- [Mn/Fe] Abundance [Mn/Fe]
86- 94 F9.4 --- [Co/Fe] Abundance [Co/Fe]
96-104 E9.1 --- [Ni/Fe] Abundance [Ni/Fe]
106-114 F9.4 --- [Y/Fe] Abundance [Y/Fe]
116-122 F7.4 --- [Ba/Fe] Abundance [Ba/Fe]
124-132 F9.4 --- [Na/Fe] Abundance [Na/Fe]
134-142 F9.4 --- [Al/Fe] Abundance [Al/Fe]
144-152 F9.4 --- [Sc/Fe] Abundance [Sc/Fe]
154-162 F9.4 --- [V/Fe] Abundance [V/Fe]
164-172 F9.4 --- [Cu/Fe] Abundance [Cu/Fe]
174-179 F6.4 --- e_[Fe/H] Abundance [Fe/H] error
181-186 F6.4 --- e_[Mg/Fe] Abundance [Mg/Fe] error
188-193 F6.4 --- e_[Si/Fe] Abundance [Si/Fe] error
195-200 F6.4 --- e_[Ca/Fe] Abundance [Ca/Fe] error
202-207 F6.4 --- e_[Ti/Fe] Abundance [Ti/Fe] error
209-214 F6.4 --- e_[Cr/Fe] Abundance [Cr/Fe] error
216-221 F6.4 --- e_[Mn/Fe] Abundance [Mn/Fe] error
223-228 F6.4 --- e_[Co/Fe] Abundance [Co/Fe] error
230-235 F6.4 --- e_[Ni/Fe] Abundance [Ni/Fe] error
237-242 F6.4 --- e_[Y/Fe] Abundance [Y/Fe] error
244-249 F6.4 --- e_[Ba/Fe] Abundance [Ba/Fe] error
251-256 F6.4 --- e_[Na/Fe] Abundance [Na/Fe] error
258-263 F6.4 --- e_[Al/Fe] Abundance [Al/Fe] error
265-270 F6.4 --- e_[Sc/Fe] Abundance [Sc/Fe] error
272-277 F6.4 --- e_[V/Fe] Abundance [V/Fe] error
279-284 F6.4 --- e_[Cu/Fe] Abundance [Cu/Fe] error
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Acknowledgements:
Danielle de Brito Silva, danielledbs.astro(at)gmail.com
(End) Patricia Vannier [CDS] 26-Nov-2024