A large high velocity cloud at l^II = 41°, b^II = −15°

Extract

In a study made by Miss Gail Smith at Leiden a cloud was found with a rather exceptional velocity and a large velocity spread. The cloud is elongated, with a ratio of length to breadth of about 3 : 1. Its length is about 10°. The average velocity relative to the local standard of rest is +90 km/sec; the width of the profiles is considerable, corresponding to a halfwidth of about 30 km/sec. The mass can be estimated only if we know the distance. Taking 200 pc as a reasonable estimate of the minimum distance of the cloud the minimum mass is about 200 solar masses. The computed mass varies as the square of the distance.