NEW NEWS today Tails of Geminga

Comet-Like Trail on a Pulsar Dec 27, A team of Italian astronomers have discovered that a pulsar racing through the Milky Way has a comet-like trail blazing behind it. The object is called Geminga, and it was previously found to have twin jets of material blasting from its poles. This new, longer tail, was uncovered by studying data archived by NASA's Chandra X-Ray Observatory. Geminga is only 500 light-years away from Earth, and moving quickly across our field of view giving astronomers a unique opportunity to study such an exotic object. Composite Image of Geminga. Image credit: XMM-Newton

Discovery of the Binary Pulsar PSR B in Very-High-Energy Gamma Rays around Periastron with H.E.S.S Aharonian, F. et al., Oct 2005, A&A 徐佩君 Hsu Pei-Chun Institute of Astronomy, NTHU

Observation H.E.S.S. February to June 2004 binary system PSR B /SS 2883 r ~ 10^13 cm (periastron) P ~ 3.4 years d ~ 1.5 kpc

Spectrum

Light curve

The orbit of PSR B

discussion B ~1G Acceleration happens very near the pulsar ?

reference Astronomy and Astrophysics, Volume 442, Issue 1, October IV 2005, pp.1-10

The H.E.S.S. project an Array of Imaging Atmospheric Cherenkov Telescopes High Energy Stereoscopic System for the investigation of cosmic gamma rays in the 100 GeV energy range located in Namibia (23o16'18'' S, 16o30'00'' E, at 1800 m asl. )