Abstract

Contributed Talk - Splinter StarFormation

Thursday, 18 September 2025, 14:54   (Benigna - Theater)

Structure and properties of molecular gas across the Milky Way

Michael Rugel
DZA/NRAO

What are the structure and properties of spiral arms across our Galaxy? How do molecular clouds form out of the atomic gas? I will discuss results on the parallax of G98.03+1.44, to date the most distant maser parallax measured in the second quadrant of the Galaxy, as well as ongoing work to constrain the locations and the morphology of the Outer and Outer-Scutum-Centaurus arms. I will present deep OH absorption observations towards strong extragalactic continuum sources in search of CO-dark molecular gas. While detecting 23 OH absorption components along three lines of sight, we only find one component without a CO detection at the same velocity. Several components show intermediate molecular gas fractions. We use these new observations to constrain the OH abundance across a variety of column densities and environments. Lastly, I will give an outlook on upcoming results from the THOR-GC survey - an expansion of The OH, HI, Recombination Line survey (THOR) towards the Galactic center and its surroundings in HI, four OH, 12 radio recombination lines as well as the L-band continuum between 1-2 GHz in full polarization, to study the interstellar medium (ISM) in the extreme conditions of the Galactic Center.