Name: Avrajit Bandyopadhyay
Affiliation: ARIES
Conference ID : ASI2022_412
Title : Li distribution and detailed abundance analysis among very metal-poor stars in the Galactic halo
Authors : Avrajit Bandyopadhyay, Thirupathi Sivarani, Timothy C. Beers, A. Susmitha, Prasanta Kumar Nayak, and Jeewan C Pandey
Abstract Type: Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : 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 towards 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 1 sigma of this relationship. We also report the non-existence of the slope of the Li plateau when studied as a function of distances from the Galactic plane, indicating mixed stellar populations. Along with Li, we have derived detailed abundances for C, odd-Z, alpha, 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 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.