2022ApJ...937...52B


Query : 2022ApJ...937...52B

2022ApJ...937...52B - Astrophys. J., 937, 52 (2022/October-1)

Li Distribution, Kinematics, and Detailed Abundance Analysis among Very Metal-poor Stars in the Galactic Halo from the HESP-GOMPA Survey.

BANDYOPADHYAY A., SIVARANI T., BEERS T.C., SUSMITHA A., NAYAK P.K. and PANDEY J.C.

Abstract (from CDS):

We present a study on the detailed elemental abundances of newly identified, bright, very metal-poor stars with the detection of lithium, initially observed as part of the SDSS/MARVELS pre-survey. These stars were selected for high-resolution spectroscopic follow-up as part of the HESP-GOMPA survey. In this work, we discuss the Li abundances detected for several stars in the survey, which include main-sequence stars, subgiants, and red giants. Different classes of stars are found to exhibit very similar distributions of Li, which points toward a common origin. We derive a scaling relation for the depletion of Li as a function of temperature for giants and main-sequence stars; the majority of the samples from the literature were found to fall within 1σ (0.19 and 0.12 dex K–1 for giants and dwarfs, respectively) of this relationship. We also report the existence of a slope of the Li abundance as a function of distance from the Galactic plane, indicating mixed stellar populations. Most Li-rich stars are found to be in or close to the Galactic plane. Along with Li, we have derived detailed abundances for C, odd-Z, α-, Fe-peak, and neutron-capture elements for each star. We have also used astrometric parameters from Gaia-EDR3 to complement our study, and derived kinematics to differentiate between the motions of the stars-those formed in situ and those accreted. The stellar population of the Spite plateau, including additional stars from the literature, is found to have significant contributions from stars formed in situ and through accretion. The orbits for the program stars have also been derived and studied for a period of 5 Gyr backwards in time.

Abstract Copyright: © 2022. The Author(s). Published by the American Astronomical Society.

Journal keyword(s): Stellar atmospheres - Abundance ratios - Stellar abundances - Lithium stars - Metallicity - Population II stars - Chemically peculiar stars - High resolution spectroscopy - Stellar nucleosynthesis - Nucleosynthesis - Stellar populations

Simbad objects: 17

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Number of rows : 17
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 TYC 2265-34-1 Pe* 00 24 00.6314583264 +32 03 11.362672548   11.93 11.58     ~ 1 0
2 NGC 104 GlC 00 24 05.359 -72 04 53.20     4.09     ~ 4158 0
3 UCAC4 557-006427 Pe* 03 15 22.0048677646 +21 23 24.580741208   13.565 12.794 12.698   ~ 1 0
4 TYC 3778-529-1 Pe* 06 43 01.8624542088 +59 34 30.892948644   11.91 11.40     ~ 8 0
5 TYC 2949-170-1 Pe* 06 46 55.6128153912 +41 16 20.480021436   11.82 11.14     ~ 3 0
6 TYC 2946-443-1 Pe* 06 52 52.7602795944 +41 05 06.008441136   11.99 11.36     ~ 2 0
7 UCAC4 348-061131 Pe* 10 12 25.4789623080 -20 30 06.814321956   14.651 13.476 13.271 12.196 ~ 14 0
8 TYC 3004-1231-1 Pe* 10 24 11.8280057520 +41 51 46.727151156   12.32 11.83     ~ 1 0
9 SDSS J114658.70+234357.2 err 11 46 58.700 +23 43 57.20           ~ 1 1
10 LSPM J1341+4741 Pe* 13 41 44.6114760816 +47 41 28.905615168   11.86 11.44     ~ 10 0
11 LP 227-5 Pe* 17 25 48.5547283320 +42 02 41.996919444       11.4   ~ 5 0
12 NGC 6752 GlC 19 10 52.11 -59 59 04.4           ~ 2121 0
13 LSPM J1933+4524 Pe* 19 33 44.7195067416 +45 24 10.745251488       11.1   ~ 4 0
14 TYC 3564-630-1 RG* 19 37 12.0103216392 +50 24 55.585764540   11.27 10.44     G0 29 0
15 BD+41 3530 Pe* 19 53 44.2128118584 +42 22 50.325013056   9.61 9.16     F5 9 0
16 BPS CS 22893-0010 Pe* 22 58 11.7253311672 -11 56 45.431946204   15.34 14.73 14.70   ~ 19 0
17 NAME Gaia Enceladus-Sausage St* ~ ~           ~ 860 0

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