OH 18 cm observations of the intermediate-velocity molecular cloud G211+63.

We detected OH 18 cm main line emission from 5 of 7 positions in the intermediate-velocity molecular cloud (IVMC) G211+63. These are the first detections of hydroxyl in IVMCs. Our OH detections at AV levels ranging from 0.24 to 0.27 mag reinforce the notion that these lines can efficiently trace diffuse, low-extinction molecular gas. N (OH) is derived for a range of excitation temperatures (5–30 K) and likely falls between 1 and 16 × 10 $$^{13}\, {\rm cm}^{-2}$$. The corresponding N (H2) values are consistent both with estimates derived from E (B − V) and CO data. Estimates of the cloud mass from the OH data range from 26 to 820 M⊙ for distances from 100 to 400 pc and T ex from 5 to 10 K. These values are 3–20 times less than the virial mass of the cloud. It is likely IVMCs resemble high-latitude clouds in this respect. If so, they are transient structures breaking up on time-scales of $${\sim }10^6\, {\rm yr}$$. [ABSTRACT FROM AUTHOR]