Moscadelli, Luca., Cesaroni, Riccardo., Beltrán, María., Rivilla, Victor. 2021. The ionized heart of a molecular disk. ALMA observations of the hyper-compact HII region G24.78+0.08 A1. Astrophysics of Galaxies (astro-ph.GA), Solar and Stellar Astrophysics, 10
The study of hyper-compact (HC) or ultra-compact (UC) HII regions is fundamental to understanding the process of massive (> 8 M_sun) star formation. We employed Atacama Large Millimeter/submillimeter Array (ALMA) 1.4 mm Cycle 6 observations to investigate at high angular resolution (~0.050″, corresponding to 330 au) the HC HII region inside molecular core A1 of the high-mass star-forming cluster G24.78+0.08. We used the H30alpha emission and different molecular lines of CH3CN and 13CH3CN to study the kinematics of the ionized and molecular gas, respectively. At the center of the HC HII region, at radii ~500 au), and an inner ionized disk (
