Physical Society Colloquium
Interview for Faculty Position
Nuclear Burning and Internal Heating on Accreting
Neutron Stars
Ed Brown
Enrico Fermi Institute
University of Chicago
The past few years have witnessed considerable progress on our understanding
of the internal structure of neutron stars; this has been driven in large
part by advances in X-ray astronomy and the promise of future gravitational
wave detectors. Many neutron stars accrete hydrogen- and helium-rich gas from
a companion star. The accretion of material modifies the mechanical and
thermal structure of the outermost layers of the neutron star and gives rise
to a host of phenomena, including type I X-ray bursts and super bursts.
Compression of the underlying crust induces reactions that heat the deep
crust and core; this heating is balanced by neutrino emission from the core.
In this talk, I shall describe the nuclear and thermal evolution of accreted
matter: burning to heavy elements, unstable carbon fusion, and pycnonuclear
reactions at densities a trillion times that of water. I shall review what
the recently discovered super bursts can teach us about the crust of the
neutron star, and how observations of transiently accreting neutron stars are
useful for constraining the equation of state and neutrino emissivity of the
netron star's core.
Thursday, January 23rd 2003, 13:30
Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103)
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