Speaker
Norbert S. Schulz
(Massachusetts Institute of Technology)
Description
4U 1626-67 is an ultra-compact binary pulsar with a pulse period
of 7.7 sec and an orbital period of 40 min. Its X-ray spectrum
varies distinctively before and after torque
reversal episodes. 4U 1626-67 is a peculiar ultra-compact binary
in that it not only truncates its accretion disk at the magnetospheric
radius, but also emits Ne and O Doppler X-ray lines, The nature of
these lines have remained quite mysterious but we can now show that
these lines originate from a coronal type plasma with temperatures
up to 10 Million degrees located at the magnetospheric radius.
We also observe consistent variations in the disk lines before and
after torque reversal. The observed disk lines constrain the angle
of inclination to 38 degrees, which is is significally larger
than previously assumed. We discuss these findings in the context
of accreting X-ray binaries and binary pulsar properties.
Primary author
Norbert S. Schulz
(Massachusetts Institute of Technology)
Co-authors
Deepto Chakrabarty
(MIT)
Herman Marshall
(MIT)
