Talk abstract

The lambda Orionis Star Forming Region (1-6 Myr, 400 pc) is a complex of star forming clouds surrounded by a molecular ring with ~5 deg radius which was probably formed by a supernova explosion. For a complete picture of star formation, believed to be determined by the supernova blast, the large-scale distribution of the pre-main sequence population in lambda Ori needs to be examined. We have embarked on a multi-wavelength study (XMM-Newton/X-ray, CFHT/optical, Spitzer/IR) of selected areas within this intriguing star forming complex that enable us to identify young stars and brown dwarfs. Our study comprises various areas within the cloud complex, including the central star cluster Collinder 69, the dark clouds B30, B35, LDN1603 and LDN 1588 within the cavity, and a concentration of B stars near the north-east of the molecular ring. This data set is among the most extended X-ray surveys carried out with XMM-Newton in a coherent star forming environment. Here, I discuss the results of our multi-wavelength study for the central cluster Collinder 69 with an updated census of the low-mass stellar population. I present initial results from a comparison
of the properties of the young stars among the lambda Ori subgroups (X-ray luminosity function, spatial distribution, age, disk fraction, IMF).