Statistical Confirmation of a Stellar Upper Mass Limit

We derive the expectation value for the maximum stellar mass ( m max ) in an ensemble of N stars, as a function of the initial mass function (IMF) upper mass cutoff ( m up ) and N . We statistically demonstrate that the upper IMF of the local massive star census observed thus far in the Milky Way and Magellanic Clouds clearly exhibits a universal upper mass cutoff around 120-200 M ☉ for a Salpeter IMF, although the result is more ambiguous for a steeper IMF.