出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：X-ray binaries that have been unambiguously detected at TeV energies show a peculiar radio morphological variability at AU scales, which can be used to gain knowledge on the particle accelerator that powers their broadband emission. We present a multi-epoch VLBI study of LS 5039, including Very Long Baseline Array (VLBA) observations at 5 GHz covering an orbital cycle. We discuss the possible relation of LS 5039 and the pulsar PSR J1825−1446 with the nearby supernova remnant SNR G016.8−01.1 by means of proper motion studies. Our preliminary results indicate either that we are facing with a very old SNR related to LS 5039 or that it is a relatively young SNR related to PSR J1825−1446, in which case the kinematical age of this pulsar would be one order of magnitude smaller than its characteristic age. In addition, we present observations of PSR B1259−63 obtained with the Australian Long Baseline Array (LBA) at 2.3 GHz during the 2007 periastron passage. We have discovered extended and variable radio structure. The peak of the radio emission is detected outside the binary system near periastron, and the emission has a total extent of 120 AU. This is the first observational evidence that non-accreting pulsars orbiting massive stars can produce variable extended radio emission at AU scales. The discovery presented here for the young non-accreting pulsar PSR B1259−63 reinforces the link with the other two known gamma-ray binaries, namely LS 5039 and LS I +61 303, and supports the presence of pulsars in these systems as well.
