Natal kicks of neutron stars
Abstract
Knowledge of the velocity distribution of neutron stars is essential for our understanding of the rate of the double neutron stars mergers and the supernova explosion physics. Binaries with a neutron star which receive low natal kick stay bound more frequently after a supernova explosion. We have investigated the most precise parallaxes and proper motions of isolated pulsars (only interferometric measurements) and recycled radio pulsars (timing measurements) through the maximum likelihood technique. We have found that both these groups show a very broad velocity distribution, which we describe with a sum of two Maxwellians. 42% of young neutron stars are drawn from a Maxwellian with σ=77 km/s, and the remainder from a Maxwellian with σ=320 km/s. 66% of the recycled neutron stars have σ=38 km/s and remaining part has σ=150 km/s. We argue that the low and high velocities in the natal kick distribution are caused by different supernova explosion mechanisms. Neutron stars in millisecond binaries with higher velocities tend to be more massive than those in slower binaries.
- Publication:
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American Astronomical Society Meeting Abstracts #231
- Pub Date:
- January 2018
- Bibcode:
- 2018AAS...23113203I