Title: The soft gamma-ray timing- and spectral characteristics of millisecond pulsar PSR J0218+4232
Proposal ID: 0120062
Subject category: Compact Object
Principal investigator: Kuiper
Institute: SRON-Utrecht
Abstract
We propose to observe the remarkable millisecond pulsar (MSP) PSR J0218+4232 for 1000
ks with INTEGRAL to
perform a detailed study of its soft gamma-ray characteristics.
Our recent Chandra observations (0.08-10
keV) confirmed the alignment in absolute
phase of the two established X-ray peaks with the peaks in the
double peaked 100-1000
MeV gamma-ray profile. The hard spectrum at X-ray energies (photon index -0.6;
1.6-10
keV) combined with the soft spectrum at high-energy gamma-rays (index -2.6; 100-1000 MeV) indicates
that the maximum luminosity is likely reached at MeV energies.
INTEGRAL can uniquely establish the timing
and spectral characteristics in detail in the
soft gamma-ray range for this intriguing pulsar. Observations
with INTEGRAL of PSR J0218+4232 provide the best way to investigate the production sites and processes in
the magnetospheres of MSPs. Furthermore, a detailed understanding of the spectrum of PSR J0218+4232 can shed
light on the origin of relatively strong (unidentified) high-energy gamma-ray sources without obvious X-ray
counterparts.