CO Observations of the lambda-Orionis Ring

Abstract

We present results from a new 12CO (J = 1 -> 0) survey of the lambda-Orionis region. The observations cover 110 square degrees uniformly on a Nyquist-sampled grid. We discover CO-emission at levels far lower than possible in previous surveys, revealing a structure similar to that seen in IRAS 100 mu maps. We derive a total molecular mass of 1.1 x 10^4 M_sun. A possible explanation for the isolated and localised outbreak of star-formation in the region is discussed.