The Central 300 pc of the Galaxy probed by infrared spectra of H${}_3^{+}$ and CO: part I. Predominance of warm and diffuse gas and high H${}_2$ ionization rate

Takeshi Oka, T. R. Geballe, Miwa Goto +4

The molecular gas in the Central Molecular Zone (CMZ) of the Galaxy has been studied using infrared absorption spectra of H${}_3^{+}$ lines at 3.5-4.0 $\mu$m and CO lines near 2.34 $\mu$m.…