|
Throughout the history of our Galaxy, various mechanisms have contributed to its chemical enrichment, from light elements formed during the Big Bang to heavier elements produced in stars and released into the interstellar medium near the end of their lives. To understand the relative contributions of these sources to the Galactic chemical budget, we need to examine nucleosynthesis processes and star properties in detail. In this context, observations are fundamental to verify and constrain theoretical models to improve our current knowledge and better address the question, "How are the elements produced and recycled through galaxies?" This thesis focuses on the chemical abundances of two sources: (i) 12 stars from the intermediate-age globular cluster GLIMPSE-C01, and (ii) 8 Carbon Enhanced Metal-Poor (CEMP) stars. By analyzing high-resolution, high signal-to-noise ratio infrared observations using the Immersion GRating INfrared Spectrometer (IGRINS), we obtained valuable chemical abundance information. (i) Our findings reveal super-solar Fe abundances and star-to-star Na abundance variations in GLIMPSE-C01, indicating that it is the most metal-rich and youngest globular cluster hosting multiple populations in our Galaxy. (ii) The distinct chemical patterns observed in CEMP stars provide insights into stellar nucleosynthesis in the early Galaxy. We present results for fluorine abundances from carefully selected observations of 8 CEMP stars, including the detection of F at the lowest metallicity so far. Comparing these results to theoretical models, we identify inconsistencies and emphasize the significance of F measurements in constraining the properties of the chemical enrichment mechanisms in the first stars. |
|