Mapping of C+ far‐infrared emission in the inner galaxy

We have mapped the [CII] 158 μm emission over a region of about 8’ diameter towards Sgr A. The strongest C+ emission comes from a ring of gas centered on SgrA*. The ring has an inner radius of about 1.7 pc and can be traced in C+ emission out to a least 8 pc from Sgr A*. The ring is inclined about 70° to the line of sight and tilted about −20° with respect to the galactic plane. The velocity field of the C+ is that expected for a tilted, inclined thin ring which is predominantly rotating about the center. There is also substantial ‘‘turbulent’’ velocity dispersion within the ring. The C+ rotation velocity decreases with distance from the center. If the velocity field is dominated by gravitational forces, the mass distribution in the center of the Galaxy is more concentrated than that of an isothermal stellar cluster.