The ISM is a fundamental component of the Milky Way and its complexity is a current and debated topic. There is evidence for large variations in the metallicity of the neutral gas in the Solar neighbourhood, as well as evidence for a more uniform distribution. For this work we obtained high resolution (R ~ 114 000) STIS-HST spectra towards 8 bright stars within 3 kpc of the Sun. We investigate chemical variations by studying individual gas components along these lines of sight. While it is possible to well constrain the level of dust depletion from relative metal abundances, the metallicity cannot be directly measured on a component-by-component basis due to the saturation of the H absorption line. We aim to explore the degeneracy between metallicity and H gas fraction, thereby investigating the chemical diversity of the gas in the Solar neighbourhood. Preliminary results show that dust depletion along lines of sight is not homogeneous, indicating variations in the chemical enrichment of the ISM.
|
