The Connection Between Different Tracers Of The Diffuse Interstellar Medium: Kinematics

Abstract

Using visible, radio, microwave, and sub-mm data, we study several lines of sight toward stars generally closer than 1 kpc on a component-by-component basis. We derive the component structure seen in absorption at visible wavelengths from Ca II, Ca I, K I, CH, CH${}^{+},$ and CN and compare it to emission from H I, CO and its isotopologues, and C${}^{+}$ from the GOT C+ survey. The correspondence between components in emission and absorption help create a more unified picture of diffuse atomic and molecular gas in the interstellar medium. We also discuss how these tracers are related to the CO-dark H${}_2$ gas probed by C${}^{+}$ emission and discuss the kinematic connections among the species observed.

To be published in ApJ