Pulsar birthrate set by cosmic-ray positron observations
Istituto di Fisica dell'Università di Urbino, via S. Chiara, Urbino, 06129, Italy
Corresponding author: email@example.com
Accepted: 15 January 2004
The pulsar birthrate (PB) in our galaxy is a parameter known with a large uncertainty. Different estimates indicate that 1/PB ranges between 30 and 250 years. Assuming a polar-cap model for gamma-ray production in gamma-ray pulsars, positron fraction measurements in cosmic rays above a few GeV make it possible to set a limit on PB. Recent measurements of the ) ratio indicate a PB of one pulsar born every years when the uncertainty on the secondary positron calculations is taken into account. A PB compatible with this result is found even in the case of a relevant production of positrons in the pulsar outer gaps.
Key words: stars: pulsar: general / ISM: cosmic-rays
© ESO, 2004