Astronomy & Astrophysics Seminar
Speaker: Craig Heinke, University of Alberta
Title: Neutron star radius measurements using quiescent LMXBs in globular clusters: progress and problems
Date: Wed, 25 Jan 2017, 11:00 am - 12:00 pm
Location: 1400 BPS Bldg.
Quiescent low-mass X-ray binaries (qLMXBs) in globular clusters offer a promising method to constrain the physics of the neutron star (NS) interior, as their atmospheres are relatively easy to model and the distances are well-measured. High-quality X-ray spectra of several cluster qLMXBs have been obtained with Chandra and/or XMM/Newton. Spectral fitting of these qLMXBs constrains the possible ranges of mass and radius of these NSs. I will show the merits and limitations of this technique, including questions about atmospheric composition, continuing accretion, the interstellar medium, hot spots, and independent constraints on the NS masses. I will discuss several different methods of combining measurements of different quiescent LMXBs; the assumptions used have significant effects on the final output. Finally, I will show results from new XMM observations of a quiescent LMXB in M13.