Journal
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Volume 494, Issue 3, Pages 3663-3674Publisher
OXFORD UNIV PRESS
DOI: 10.1093/mnras/staa958
Keywords
methods: data analysis; methods: statistical; stars: neutron; pulsars: general
Categories
Funding
- Science and Technology Facilities Council [ST/S000275/1]
- STFC [ST/S000275/1] Funding Source: UKRI
Ask authors/readers for more resources
Understanding the natal kicks, or birth velocities, of neutron stars is essential for understanding the evolution of massive binaries and double neutron star formation. We use maximum likelihood methods as published in Verbunt et al. to analyse a new large data set of parallaxes and proper motions measured by Deller et al. This sample is roughly three times larger than number of measurements available before. For both the complete sample and its younger part (spin-down ages tau < 3 Myr), we find that a bimodal Maxwellian distribution describes the measured parallaxes and proper motions better than a single Maxwellian with probability of 99.3 and 95.0 per cent, respectively. The bimodal Maxwellian distribution has three parameters: fraction of low-velocity pulsars and distribution parameters sigma(1) and sigma(2) for low- and high-velocity modes. For a complete sample, these parameters are as follows: 42(-15)(+17) per cent, sigma(1) = 128(-18)(+22) km s(-1), and sigma(2) = 298 +/- 28 km s(-1). For younger pulsars, which are assumed to represent the natal kick, these parameters are as follows: 20(-10)(+11) per cent, sigma(1) = 56(-15)(+25) km s(-1), and sigma(2)= 336 +/- 45 km s(-1). In the young population, 5 +/- 3 per cent of pulsars have velocities less than 60 km s(-1). We perform multiple Monte Carlo tests for the method taking into account realistic observational selection. We find that the method reliably estimates all parameters of the natal kick distribution. Results of the velocity analysis are weakly sensitive to the exact values of scale lengths of the Galactic pulsar distribution.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available