Revision of Star-Formation Measures

TL;DR

This paper discusses the impact of stellar rotation on massive star evolution, showing that rotation leads to hotter, more luminous stars and significantly alters the spectral energy distributions and star-formation rate indicators.

Contribution

It introduces a revised grid of stellar evolutionary tracks including rotation, integrated into the Starburst99 code, providing updated models for star-formation measures.

Findings

Rotating massive stars are hotter and more luminous.

Hydrogen ionizing continuum increases up to 3 times with rotation.

Effects of rotation are more pronounced at shorter wavelengths and lower metallicity.

Abstract

Rotation plays a major role in the evolution of massive stars. A revised grid of stellar evolutionary tracks accounting for rotation has recently been released by the Geneva group and implemented into the Starburst99 evolutionary synthesis code. Massive stars are predicted to be hotter and more luminous than previously thought, and the spectral energy distributions of young populations mirror this trend. The hydrogen ionizing continuum in particular increases by a factor of up to 3 in the presence of rotating massive stars. The effects of rotation generally increase towards shorter wavelengths and with decreasing metallicity. Revised relations between star-formation rates and monochromatic luminosities for the new stellar models are presented.