| | |
| | |
Stat |
Members: 3645 Articles: 2'504'928 Articles rated: 2609
25 April 2024 |
|
| | | |
|
Article overview
| |
|
Population synthesis of old neutron stars in the Galaxy | S.B. Popov
; M. Colpi
; A. Treves
; R. Turolla
; V.M. Lipunov
; M.E. Prokhorov
; | Date: |
18 Oct 1999 | Subject: | astro-ph | Affiliation: | SAI), M. Colpi (Univ. of Milan), A. Treves (Univ. of Como), R. Turolla (Univ. of Padova), V.M. Lipunov (Moscow State Univ.) and M.E. Prokhorov (SAI | Abstract: | The paucity of old isolated accreting neutron stars in ROSAT observations is used to derive a lower limit on the mean velocity of neutron stars at birth. The secular evolution of the population is simulated following the paths of a statistical sample of stars for different values of the initial kick velocity, drawn from an isotropic Gaussian distribution with mean velocity $0leq < V>leq 550$ ${
m km s^{-1}}$. The spin-down, induced by dipole losses and the interaction with the ambient medium, is tracked together with the dynamical evolution in the Galactic potential, allowing for the determination of the fraction of stars which are, at present, in each of the four possible stages: Ejector, Propeller, Accretor, and Georotator. Taking from the ROSAT All Sky Survey an upper limit of $sim 10$ accreting neutron stars within $sim 140$ pc from the Sun, we infer a lower bound for the mean kick velocity, $ < V>ga 200-300$ ${
m km s^{-1}}$. The same conclusion is reached for both a constant ($Bsim 10^{12}$ G) and a magnetic field decaying exponentially with a timescale $sim 10^9$ yr. Present results, moreover, constrain the fraction of low velocity stars, which could have escaped pulsar statistics, to $la 1%$. | Source: | arXiv, astro-ph/9910320 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |