Retrieving Internal Kinematics of Galaxies with Deep Learning using Single-Band Optical Images

Abstract

Using deep machine learning we show that the internal velocities of galaxies can be retrieved from optical images trained using 4596 systems observed with the SDSS-MaNGA survey. Using only i-band images we show that the velocity dispersions and the rotational velocities of galaxies can be measured to an accuracy of 29 km s −1 and 69 km s −1 respectively, close to the resolution limit of the spectroscopic data. This shows that galaxy structures in the optical holds important information concerning the internal properties of galaxies, and that the internal kinematics of galaxies are quantitatively reflected in their stellar light distributions beyond a simple rotational vs. dispersion distinction.