 |
"A New Paradigm for X-ray Binaries" |
Prof. Philipp Podsiadlowski
University of Oxford |
| Even though low-mass X-ray binaries (LMXBs), binaries consisting of a
neutron star accreting from a low-mass companion star, have been studied
for almost 40 years, their evolution is still relatively poorly
understood. In particular, it has now been established for more
than a decade that the standard model, where their evolution is
considered similar to the evolution of cataclysmic variables (systems
similar in nature but where the compact object is a white dwarf),
cannot explain some of the main observed characteristics of LMXBs. One
important recent development has been the realization that many
(most?) "LMXBs" may in fact be intermediate-mass X-ray binaries
(IMXBs) or their descendants.
In this talk, I will first review the problems with the standard model
and study the implications of IMXBs for our understanding of X-ray
binaries and millisecond pulsars using a combination of realistic
binary evolution calculations with a binary population synthesis
approach. While the inclusion of IMXBs improves the agreement with
the observed properties of "LMXBs", several significant discrepancies
remain, which suggests that additional physical processes need to be
included in the model. One possible solution I will discuss are
irradiation-driven mass-transfer cycles. I will also present new
hydrodynamical calculations of irradiation-induced circulation in the
secondaries of X-ray binaries.
Tuesday, January 21st at 4:00 p.m.
Seminar is scheduled to be held in F235 of
the Tech Building, due to current renovations at Dearborn Observatory.
Refreshments will be served at 3:30
|
|
 |
