The effect of different magnetospheric structures on predictions of gamma-ray pulsar light curves
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Date
2014Author
Breed, M.
Venter, C.
Harding, A.K.
Johnson, T.J.
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Show full item recordAbstract
The second pulsar catalogue of the Fermi Large Area Telescope (LAT) will contain
in excess of 100 gamma-ray pulsars. The light curves (LCs) of these pulsars exhibit a variety
of shapes, and also different relative phase lags with respect to their radio pulses, hinting at
distinct underlying emission properties (e.g., inclination and observer angles) for the individual
pulsars. Detailed geometric modelling of the radio and gamma-ray LCs may provide constraints
on the B-field structure and emission geometry. We used different B-field solutions, including
the static vacuum dipole and the retarded vacuum dipole, in conjunction with an existing
geometric modelling code, and constructed radiation sky maps and LCs for several different
pulsar parameters. Standard emission geometries were assumed, namely the two-pole caustic
(TPC) and outer gap (OG) models. The sky maps and LCs of the various B-field and radiation
model combinations were compared to study their effect on the resulting LCs. As an application,
we compared our model LCs with Fermi LAT data for the Vela pulsar, and inferred the most
probable configuration in this case, thereby constraining Vela’s high-altitude magnetic structure
and system geometry
URI
http://hdl.handle.net/10394/32125http://events.saip.org.za/getFile.py/access?resId=0&materialId=5&confId=14