Massive star formation in the galaxy

The relevant characteristics of the galactic disk are summarized. OB star formation rates can be estimated from Lyman continuum photon production rates and warm dust luminosities, respectively, and total SFRs can be inferred if an Initial Mass Function is adopted. We apply this procedure to the galactic disk. Resulting star formation rates and lockup rates. Bimodal star formation in the galactic disk means that two different mechanisms of star formation are at work. In the galactic disk about ∼ 2/3 of all OB stars are formed via induced star formation. The bimodal initial mass function, together with star formation in a closed system, and spontaneous and induced SFRs being both proportional to the amount of molecular hydrogen, connects the observed present-day OB SFR correctly with the total mass distribution. The total bimodal star formation rate in the galactic disk is given. The average star formation efficiency in molecular clouds is ε ∼ 10-9 Τcl ∼ (1-10)%, with estimated lifetimes of molecular clouds ranging from Τcl ∼ 107-108yr