Discovery of PSR 1259-63 in VHE Gamma-Rays with H.E.S.S.
ATel #249; M. Beilicke, Universitaet Hamburg; M. Ouchrif, Laboratoire de Physique Nucleaire de Haute Energie, Universite Paris VI and VII; G. Rowell, Max-Planck-Institut fuer Kernphysik; and S. Schlenker, Humboldt-Universitaet, Berlin; on behalf of the H. E.S. S. (High Energy Stereoscopic System) Collaboration
on 12 Mar 2004; 07:32 UT
Distributed as an Instant Email Notice Request For Observations
Credential Certification: Michael Punch (punch@in2p3.fr)
Subjects: Gamma Ray, >GeV, Request for Observations, Binary, Pulsar
We report detection of very-high-energy gamma-ray emission from the binary millisecond pulsar PSR 1259-63 (1236.72-day orbit) by the H.E.S.S. experiment above a threshold of about 200 GeV (in the observed zenith-angle range, 40o-45o) at the 5.9-sigma level, where previously upper limits were reported by the CANGAROO collaboration (Kawachi et al. 2004, Ap.J., in press). The source was observed for a total of 4.6 hr live-time between Feb. 26 and Mar. 5 with the full four-telescope Cherenkov array. Preliminary estimates yield a flux at about 10 percent of the level of the Crab nebula (0.4 photons/min gamma-ray excess detected after selection cuts). Periastron passage of the pulsar was expected on Mar. 7.43 UT.
Observations at other wavelengths are strongly encouraged, especially on Mar. 20-25, when the neutron star will cross the inclined Be disk for the second time.
Observations with H.E.S.S. are scheduled to recommence on Mar. 14, after the bright-moon period.
Particle acceleration associated with the pulsar wind is predicted to result in observable GeV/TeV emission also after periastron (Kirk et al. 1999, Astroparticle Phys. 10, 31).
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