Star Formation, Stellar Feedback, and the Ecology of Galaxies

Star Formation, Stellar Feedback, and the Ecology of Galaxies

Kinetic tomography of the Galactic disk: the local ISM motions revealed by 3D dust, atomic and molecular line emission, and machine vision

We present a reconstruction of the motions in the interstellar medium (ISM) based on the combination of a state-of-the-art three-dimensional model of the dust distribution within 1.25 kpc from the Sun and the line emission observations from neutral atomic hydrogen (HI) and carbon monoxide (CO) within the Galactic latitude |b| < 5 deg. We combined the data using the histogram of oriented gradient (HOG) method, a computer vision technique for evaluating the morphological correlation between images. Using the HOG method, we assigned line-of-sight (LOS) velocities to the dust parcels across distances and produced a face-on map of the local ISM's heliocentric motions. We employed the resulting distance-LOS velocity maps to calculate the amplitude of streaming motions, kinetic energy and momentum distributions, and the mass flow rates in the local ISM. We report the global averages of these fundamental quantities and the fluctuations that reveal the input from stellar feedback and its imprint in the large-scale gas dynamics in the Solar neighborhood.