Abstract :
Neutral atomic hydrogen (HI) represents more than half of the gas mass in the Milky Way. It is a critical tracer of interstellar medium (ISM) dynamics, sampling both the cold, pre-molecular state that precedes star formation and the warm, diffuse ISM that exists before and after star formation. However, its ubiquity and complex structure have made
it hard to integrate HI into the general picture of star formation, until now. I will present a reconstruction of the local ISM motions produced by combining HI emission observations with a state-of-the-art three-dimensional model of the dust distribution within 1.25 kpc from the Sun. Using the histogram of oriented gradients (HOG) machine vision algorithm, we exploited the morphological similarity between these tracers to assign line-of-sight velocities to the dust parcels
across distances and produce a face-on map of the local ISM's heliocentric motions. We used the resulting maps to calculate the amplitude of streaming motions, kinetic energy and momentum distributions, and the mass flow rates in the local ISM. I will report the global averages of these fundamental quantities and the fluctuations that reveal the input from stellar feedback and the imprint of large-scale gas dynamics in the Solar neighborhood. Finally, I will introduce my Orion and nearby molecular clouds Dynamics of Ionized and Neutral gas (ODIN) program, a Jansky Very Large Array survey designed to produce and scientifically exploit the highest-resolution extended HI emission maps of the most prominent
nearby star-forming regions.
