Observing the PWN G21.5-0.9 with Suzaku: A source of high-energy cosmic rays?
Abstract
Pulsars convert their spin-down energy into a relativistic magnetised wind, which interacts with the surrounding supernova remnant (SNR) or interstellar medium (ISM) to create a pulsar wind nebula (PWN), as in the Crab Nebula which is viewed as the prototype for a PWN. Particle acceleration to very high energies occurs in the pulsar winds or at the shocks located where the wind interacts with the surrounding medium. Studies of PWN at high energies (>10 keV) are important in understanding the mechanism of particle acceleration. G21.5-0.9 is a composite Galactic SNR. G21.5-0.9 has recently been discovered to be a PWN surrounded by a non-thermal X-ray halo with limb-brightening at its boundary suggesting a site for cosmic ray acceleration. The halo has also been found to contain thermal knots which indicate the position of the reverse shock. The pulsar in G21.5-0.9 (J1833-1034) is the second most energetic in our Galaxy, with a spin-down luminosity below only that of the Crab pulsar. The Hard X-ray Detector (HXD) on Suzaku has the lowest background rate to date of any instrument in the energy range 10-600 keV. Young SNRs have been thought to accelerate cosmic rays up to TeV energies, making the HXD a valuable instrument in studying them. G21.5-0.9 is thought to be under 1000 years old, making it one of the youngest PWN currently known. We will present the results of a 68 ks Suzaku observation of G21.5-0.9 targeted to characterise the hard X-ray spectrum and shed light on the acceleration of cosmic rays in this SNR.
- Publication:
-
37th COSPAR Scientific Assembly
- Pub Date:
- 2008
- Bibcode:
- 2008cosp...37.1948M