Abstract
We present a statistical analysis of the X-ray luminosity of rotation-powered pulsars and their surrounding nebulae
using the sample of Kargaltsev & Pavlov, and we complement this with an analysis of the γ -ray emission of
Fermi-detected pulsars. We report a strong trend in the efficiency with which spin-down power is converted to
X-ray and γ -ray emission with characteristic age: young pulsars and their surrounding nebulae are efficient X-ray
emitters, whereas in contrast old pulsars are efficient γ -ray emitters. We divided the X-ray sample in a young
(τc <1.7 × 104 yr) and old sample and used linear regression to search for correlations between the logarithm
of the X-ray and γ -ray luminosities and the logarithms of the periods and period derivatives. The X-ray emission
from young pulsars and their nebulae are both consistent with LX ∝ ˙ P3/P 6. For old pulsars and their nebulae the
X-ray luminosity is consistent with a more or less constant efficiency η ≡ LX/ ˙Erot ≈ 8 × 10−5. For the γ -ray
luminosity we confirm that Lγ ∝
√
˙E
rot. We discuss these findings in the context of pair production inside pulsar
magnetospheres and the striped wind model. We suggest that the striped wind model may explain the similarity
between the X-ray properties of the pulsar wind nebulae and the pulsars themselves, which according to the striped
wind model may both find their origin outside the light cylinder, in the pulsar wind zone.
Original language | English |
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Pages (from-to) | 131/1-131/5 |
Number of pages | 5 |
Journal | Astrophysical Journal |
Volume | 727 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2011 |