The Mass of the Vela Pulsar Progenitor and the Age of the Vela-Puppis Complex

Abstract

The association of the Vela Pulsar with the Vela Supernova Remnant has long supported the hypothesis that core-collapse supernovae yield neutron stars, but its surrounding stellar population now offers new insights into progenitor evolution. By age-dating stars within 150 pc of the Vela Pulsar, we infer properties of its progenitor. These stars belong to the Vela-Puppis complex, revealing the region’s star formation history. While stellar population models with standard assumptions suggest a likely progenitor age and mass, these predictions are internally inconsistent with the observed population, indicating that something is missing in the standard modeling approach. With those assumptions, there is very weak support for a ≲10 Myr old population, moderate support for a 40 Myr old population, and strong support for an intermediate-age population around 65–100 Myr old. The ≲10 Myr signal hinges on two peculiar O stars, which are unlike any others in the Vela-Puppis complex and imply nearly three times more main-sequence (MS) stars than are observed. The 40 Myr old population is supported by six red supergiants and several Be stars, but this population is again marginally inconsistent with the observed distribution of MS stars. The red giant and MS distributions are consistent with a 65–100 Myr old population. We discuss several possible resolutions, emphasizing how binary evolution and/or very rapid rotation could resolve these discrepancies. Gaia parallaxes and Stellar Ages enable these results; Stellar Ages is a novel stellar population modeling algorithm that combines individual and population-level age inferences.

Keywords

• Core-collapse supernovae
• Pulsars
• Stellar associations
• Multiple star evolution