High-mass X-ray binaries in nearby galaxies

Jun Yang

University of Utah

The overall objective of my research is to improve understanding of the properties and structures of high-mass X-ray binary (XRB) pulsars, by bringing together a large set of observations spanning the observable parameter space in spin period, luminosity, and environment. To reach this goal we analyze and compare all available and relevant (~17 years) observations of the Small Magellanic Cloud (SMC), Large Magellanic Cloud (LMC), and Irregular Galaxy IC 10, from 3 space astronomy satellites: X-ray Multi-Mirror Mission-Newton (XMM-Newton), the Chandra X-ray Observatory and Rossi X-ray Timing Explorer (RXTE), to explore the time evolution of the X-ray pulsars. This time-domain library includes high time-resolution light curves, periodograms, spectra, event lists, and complete histories of spin period derivatives, pulse fraction, etc., for each pulsar. Furthermore, IC 10 and M33 are explored as a comparison sample to study the star formation. Especially IC 10 is the closest known starburst galaxy and its well-constrained starburst age of 10 Myrs makes it a unique resource for studying the origin and evolution of compact objects. A NuSTAR survey of M33 was conducted to study the distribution of XRB accretion states in an actively star-forming environment.  I will discuss the details about their compact object types and accretion states using NuSTAR color-intensity and color-color diagrams.