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| Paper: |
Binary Pulsar B1259–63 Spectrum Evolution
and Classification of Pulsar Spectra |
| Volume: |
466, Electromagnetic Radiation from Pulsars and Magnetars |
| Page: |
75 |
| Authors: |
Dembska, M.; Kijak, J.; Lewandowski, W. |
| Abstract: |
Recently published results (Kijak et al. 2011a) indicated
the evidence for a new aspect in radio pulsars spectra. We studied the
radio spectrum of PSR B1259–63 in an unique binary with Be star LS 2883
and
showed that this pulsar undergoes
a spectrum evolution due to the orbital motion.
We proposed a qualitative model which explains this evolution. We considered
two mechanisms that might influence the observed radio emission: free-free
absorption and cyclotron resonance. According to the published results (Kijak et al. 2011b),
there were found objects with a new type of pulsar radio spectra,
called gigahertz-peaked spectra (GPS) pulsars. Most of them were found
to exist in very interesting environments. Therefore, it is suggested that the
turnover phenomenon is associated with the environment, rather than being related
intrinsically to the radio emission mechanism. Having noticed an apparent
resemblance between the B1259-63 spectrum and the GPS, we suggested that
the same mechanisms should be responsible for both cases. Thus, we believe
that this binary system can hold the clue to the understanding of the gigahertz-peaked
spectra of isolated pulsars.
Using the same database we constructed spectra for chosen
observing days and obtained different types of spectra. Comparing to current
classification of pulsar spectra, there occurs a suggestion that the appearance
of various spectra shapes, different from a simple power law which is typical for
radio pulsars, is possibly caused by environmental conditions around neutron
stars. |
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