Download Department of Physics University of Vermont Physics around Pulsars: A Fast Spinning,

Physics around Pulsars: A Fast Spinning,
Highly Magnetized Conducting Sphere
Pulsars are rotating and radiating neutron stars
and are superb astrophysical laboratories of
extreme physics. A typical neutron star has
radius of ~ 10 km, magnetic field of ~ 1012
Gauss, density of ~ 1017 kg/m3, rotating at a
frequency ~1 Hz and has a surface gravity of ~
1012m/s2. We observe pulsars as a sequence of
periodic pulses mostly in the radio wavelength.
What is mind-boggling is that the radio
emission arises from a kilometer-sized emission
patch which is at a distance of ~1019 meter from
us, and yet we see it!! The equivalent
blackbody temperature of this radio emission is
in the range 1025 – 1030 K, which exceeds the
limit for any incoherent emission process. The
physical mechanism of how this emission is
generated is considered as one of the most
challenging problems in astrophysics.
In this talk, I will discuss the wide spectrum of
physical
phenomena
(like
the
QED
phenomenon of magnetic pair creation, effect
on the structure of neutron star surface,
relativistic plasma dynamics etc.) that takes
place around the fast rotating, highlymagnetized neutron star. These processes lead
to generation of a highly relativistic flow of
electron positron plasma in which we believe
the radio emission is excited by a process called
coherent curvature radiation, where charged
“bunches” are accelerated in curved magnetic
field. I will discuss how evidence from high
quality radio and X-ray observations of pulsars
is putting stringent constraints to these ideas.
Department of Physics
University of Vermont
Theoretical and
Applied Physics
Fall 2015
Dr. Dipanjan Mitra
Department of Physics
University of Vermont
Wednesday, September 30
3:30 PM
Kalkin 003
Refreshments will be
available in Cook Science at
3:00 PM.
uvm.edu/physics
@uvmphysics