J/ApJ/903/88 Ions individual abundances in LAMOST J1109+0754 (Mardini+, 2020)
Cosmological Insights into the Early Accretion of.
Mardini M.K., Placco V.M., Meiron Y., Ishchenko M., Avramov B.,
Mazzarini M., Berczik P., Sedda M.A., Beers T.C., Frebel A., Taani A.,
Donnari M., Al-Wardat M.A., Zhao G.
<Astrophys. J., 903, 88 (2020)>
=2020ApJ...903...88M 2020ApJ...903...88M
ADC_Keywords: Stars, metal-deficient; Spectra, optical; Abundances
Keywords: Chemically peculiar stars ; Population III stars ; R-process ;
Stellar kinematics ; Chemical abundances ; Stellar dynamics ;
Orbits ; Galaxy dynamics
Abstract:
This study presents a comprehensive chemodynamical analysis of
LAMOSTJ1109+0754, a bright (V=12.8), extremely metal-poor
([Fe/H]=-3.17) star, with a strong r-process enhancement
([Eu/Fe]=+0.94±0.12). Our results are based on the 7D measurements
supplied by Gaia and the chemical composition derived from a
high-resolution (R∼110000), high signal-to-noise ratio (S/N∼60)
optical spectrum obtained by the 2.4m Automated Planet Finder
Telescope at Lick Observatory. We obtain chemical abundances of 31
elements (from lithium to thorium). The abundance ratios ([X/Fe]) of
the light elements (Z≲30) suggest a massive Population III progenitor
in the 13.4-29.5M☉ mass range. The heavy-element (30<Z≲90)
abundance pattern of J1109+075 agrees extremely well with the
scaled-solar r-process signature. We have developed a novel approach
to trace the kinematic history and orbital evolution of J1109+0754
with a cOsmologically deRIved timE-varyiNg Galactic poTential (the
ORIENT) constructed from snapshots of a simulated Milky Way analog
taken from the Illustris-TNG simulation. The orbital evolution within
this Milky Way-like galaxy, along with the chemical abundance pattern,
implies that J1109+0754 likely originated in a low-mass dwarf galaxy
located ∼60kpc from the center of the Galaxy, which was accreted
∼6-7Gyr ago, and that the star now belongs to the outer-halo
population.
Description:
LAMOSTJ1109+0754 was originally followed up with high-resolution
spectroscopy on 2014 May 9, using the SUBARU telescope and the echelle
High Dispersion Spectrograph (HDS).
On 2015 May 14, J1109+0754 was also observed with the Automated Planet
Finder Telescope (APF). The observing setup yielded a spectral
resolving power of R∼110000.
Objects:
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RA (2000) DE Designation(s)
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11 09 01.22 +07 54 41.8 LAMOST J1109+0754 = LAMOST J110901.22+075441.8
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 46 267 Lines, atomic data, EWs, and individual abundances
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See also:
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/ApJS/61/667 : Kinematics of Galactic old population (Norris 1986)
J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)
J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)
J/ApJ/819/135 : Lithium-rich giants in globular clusters (Kirby+, 2016)
J/ApJ/844/18 : RAVE J203843.2-002333 high-resolution spectro. (Placco+, 2017)
J/ApJ/848/L16 : Counterpart of GW170817. I. DECam obs. (Soares-Santos+, 2017)
J/ApJ/858/92 : RPA Southern Pilot Search of 107 Stars (Hansen+, 2018)
J/AJ/156/179 : Highly r-process-enhanced field * kinematics (Roederer+, 2018)
J/ApJ/865/129 : Abundance analysis of HD 222925 (Roederer+, 2018)
J/ApJ/868/110 : R-Process Alliance: 1 release in Galactic halo (Sakari+, 2018)
J/ApJ/875/89 : Metal-poor stars with APF I. LAMOST CEMP stars (Mardini+, 2019)
J/ApJ/882/27 : Metal-poor stars with APF II. MW halo stars (Mardini+, 2019)
J/ApJ/874/148 : Metal-poor star RAVEJ093730.5-062655 abundances (Sakari+, 2019)
J/ApJ/898/150 : High-res. MIKE obs. of metal-poor stars (Ezzeddine+, 2020)
J/ApJS/249/30 : R-Process Alliance: metal-poor star spectro. (Holmbeck+, 2020)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Ion Species
7- 14 F8.3 0.1nm lambda [3874/6708] Wavelength, Angstroms
16- 20 F5.3 eV ExPot [0/4.44]? Excitation potential
22- 27 F6.3 [-] loggf [-9.82/0.58]? Log oscillator strength
29- 31 A3 --- f_EW Flag on EW (1)
33- 38 F6.2 10-13m EW [1.5/107]? Equivalent width, 10-3Å
40- 40 A1 --- l_logeps [<] Limit flag on logeps
42- 46 F5.2 [Sun] logeps [-2.05/6.57] Log number abundance of Ion
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Note (1): Flag as follows:
syn = indicates that abundances were derived by spectral synthesis matching
(60 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 02-Feb-2022