Chemodynamic Analysis of Four r-Process Enhanced Stars Observed with GTC
Abstract
Here, we delineate a comprehensive abundance analysis of four r-process enhanced metal-poor stars observed with HORuS spectrograph on a 10-m class telescope, GTC. The high signal-to-noise ratio at R≈25000 spectral resolution allowed us to detect 16 light and 20 neutron-capture elements along with Th in two stars. Four of our program stars show signatures of mixing in their atmosphere. Through detailed abundance analysis of four r-process enhanced stars together with already identified r-process-rich stars in literature, we probe the production sites of neutron-capture elements. The [Zr/Eu] ratio as a function of metallicity shows the evidence of multiple channels for the production of r-process. Thorium to first and second r-process peak elements ratios also support the similar non-universality of neutron-capture elements. An increased sample of r-process enhanced stars will enable us understand different formation channels of neutron capture elements. Using the kinematic analysis, we found the clues of accretion for two of our program stars.