On the First Generation of Stars

Abstract

We argue that the first stars may have spanned the conventional mass range rather than be identified with the Very Massive Objects (100-1000 solar masses) favoured by numerical simulations. Specifically, we find that magnetic field generation processes acting in the first protostellar systems suffice to produce fields that exceed the threshold for MRI instability to operate and thereby allow the MRI dynamo to generate equipartition-amplitude magnetic fields on protostellar mass scales below 50 solar masses. Such fields allow primordial star formation to occur at essentially any metallicity by regulating angular momentum transfer, fragmentation, accretion and feedback in much the same way as occurs in conventional molecular clouds.