OBSERVATIONS OF PULSARS , PSR 1509 − 58 AND PSR 1259 − 63 , BY CANGAROO 3 . 8 m TELESCOPE
نویسندگان
چکیده
The data for VHE (∼TeV) gamma rays from young gamma-ray pulsar PSR1509-58 observed in 1996 with the CANGAROO 3.8mČerenkov imaging telescope are presented, as well as the additional data from March to June of 1997. The high spin-down luminosity of the pulsar and the plerionic feature around the pulsar observed with radio and X-rays suggest that VHE gamma-ray emission is quite likely above the sensitivity of the CANGAROO telescope. The CANGAROO results on other pulsars, such as PSR1259-63, are also presented. PSR1259-63 is a highly eccentric X-ray binary system, which includes a high mass Be companion star, and a preliminary analysis on the data taken 4 months after the periastron in 1994 suggests emission of VHE gamma rays. INTRODUCTION Extensive efforts have been made for detecting VHE gamma rays from galactic objects which are considered to be VHE gamma ray emitters such as pulsars, supernova remnants and EGRET sources. The Crab, PSR B1706-44 and the Vela pulsars are found to be VHE gamma ray sources by using imagingČerenkov telescope, and, as these examples indicate, a young rotation-powered pulsar is a likely accelerator of non-thermal energetic particles. A shock mechanism may occur between the pulsar wind and circumstellar matter to form a pulsar nebula, where particle acceleration and/or randomization of the pulsar wind flow of relativistic particles takes place. Non-thermal phenomena have been seen by radio and X-ray synchrotron emission, but more direct evidence for the existence of the relativistic electrons in such nebulae can be given by the
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