An x-ray tour of massive-star-forming regions with Chandra

Summary

The Chandra X-ray Observatory is providing fascinating new views of massive-star–forming regions, revealing all stages in the life cycles of massive stars and their effects on their surroundings. I present a Chandra tour of some of the most famous of these regions: M17, NGC 3576, W3, Tr14 in Carina, and 30 Doradus. Chandra highlights the physical processes that characterize the lives of these clusters, from the ionizing sources of ultracompact H II regions (W3) to superbubbles so large that they shape our views of galaxies (30 Dor). X-ray observations usually reveal hundreds of pre-main sequence (lower-mass) stars accompanying the OB stars that power these great H II region complexes, although in one case (W3 North) this population is mysteriously absent. The most massive stars themselves are often anomalously hard x-ray emitters; this may be a new indicator of close binarity. These complexes are sometimes suffused by soft diffuse x-rays (M17, NGC 3576), signatures of multi-million-degree plasmas created by fast O-star winds. In older regions we see the x-ray remains of the deaths of massive stars that stayed close to their birthplaces (Tr14, 30 Dor), exploding as cavity supernovae within the superbubbles that these clusters created.

Revealing the life cycle of a massive stellar cluster

High-resolution x-ray images from the Chandra X-ray Observatory and XMM-Newton elucidate all stages in the life cycles of massive stars—from ultracompact H II (UCHII) regions to supernova remnants—and the effects that those massive stars have on their surroundings.