Probing the Galactic s-process nucleosynthesis using barium stars

The origin and evolution of neutron-capture elements in our Galaxy is poorly understood. In this work, we have attempted to understand the Galactic s-process nucleosynthesis using barium stars as probes. We have performed high resolution spectroscopic analysis for three barium stars HD 36650, HD 207585 and HD 219116. The analysis of HD 219116 is based on HCT/HESP data at a resolution of 60,000 covering a wavelength region 3530-9970 A° . For HD 36650, we have used the FEROS spectrum at a resolution of 48,000 covering the wavelength region 3520-9200 A° . For HD 207585, the spectrum from VLT/UVES at a resolution of 48,000 covering the wavelength region 3290-6650 °A is used. Our analysis clearly shows that the surface chemical composition of these barium stars are enriched by s-process nucleosynthesis products coming from their former companion low-mass AGB stars. A discussion on the distriburtion of abundance ratios based on the existing nucleosynthesis theories is presented.