| Name: | Pallavi Saraf |
| Affiliation: | Indian Institute of Astrophysics, Bangalore |
| Conference ID : | ASI2024_238 |
| Title : | Chemodynamics of newly discovered very metal-poor stars to investigate the thick disk and halo formation from HESP-GOMPA survey |
| Authors : | Pallavi Saraf and Thirupathi Sivarani |
| Authors Affiliation: | Indian Institute of Astrophysics, Bangalore |
| Mode of Presentation: | Poster |
| Abstract Category : | Stars, Interstellar Medium, and Astrochemistry in Milky Way |
| Abstract : | Asteroseismology-based time-resolved study of the Milky Way formation has shown that the MW thick disk formation started very early (0.8 Gyr after the Big Bang), which is contradictory to our earlier understanding. This timescale is even earlier than the formation of MW inner halo stars. Hence, studies of metal-poor stars need to consider the kinematic association of MW stars for more precise chemical tagging. Here, we present chemical abundance trends for about 40 newly discovered bright Metal-Poor stars (−3.1 < [Fe/H] < −2.0) using the Hanle Echelle Spectrograph installed at the 2m Himalayan Chandra Telescope. This is an interesting metallicity range where a significant change in the abundance trends of key elements indicating major milestones in the galaxy evolution or operation of new nucleosynthesis sites is expected. The results include the discovery of new r-process-enhanced stars, EMP stars, and spectroscopic binaries. These 40 sample stars are kinematically separated into Halo and thick disks to study the delay time in the production of alpha elements versus the n-capture elements among two Galactic components as they have different chemical enrichment histories. We compare them with other halo stars and their abundance trends. Some of the interesting stars we compare it with SNe yields and infer the progenitors. Many of these bright stars with detailed abundances could form benchmark stars for future metal-poor star surveys, due to the possibility of deriving abundances for a large number of elements. |
