Letter to the Editor
Observational constraints on kicks in supernovæ
Simon F. Portegies Zwart 1, 2,
Marco L. A. Kouwenhoven 2 and
Alastair P. Reynolds 2, 3
Received 15 August 1997 / Accepted 2 September 1997
The absence or presence of extremely wide binaries with a radio pulsar and an optical counterpart imposes a strong constraint on the existence and magnitude of kicks in supernova explosions. We search for such systems by comparing the positions of radio pulsars which are not known to be in binaries with the positions of visible stars, and find that the number of associations is negligible. According to the performed population synthesis, this implies that kicks must occur, with a lower limit of at least 10 to 20 km s-1.
The single 13-th magnitude star at a distance of 4.9 seconds of arc from the pulsar PSR B1929+10 is a good candidate to be the member of such a wide pair. If it turns out that this pulsar is indeed the member of a wide binary or if another wide pair will be found in the future, the kick-velocity distribution must have a significant contribution from low-velocity kicks.
Key words: methods: statistical catalogs binaries: general pulsars: general pulsars: individual: PSR B1929+10
Send offprint requests to: Simon Portegies Zwart: firstname.lastname@example.org
© European Southern Observatory (ESO) 1997
Online publication: March 26, 1998