Volume 396, Number 3, December IV 2002
|Page(s)||917 - 921|
|Section||Interstellar and circumstellar matter|
|Published online||05 December 2002|
Moments of inertia for neutron and strange stars: Limits derived for the Crab pulsar
N. Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, 00-716 Warszawa, Poland e-mail: email@example.com
Corresponding author: M. Bejger, firstname.lastname@example.org
Accepted: 1 October 2002
Recent estimates of the properties of the Crab nebula are used to derive constraints on the moment of inertia, mass and radius of the pulsar. To this purpose, we employ an approximate formula combining these three parameters. Our “empirical formula” , where , is based on numerical results obtained for thirty theoretical equations of state of dense matter. The functions for neutron stars and strange stars are qualitatively different. For neutron stars for (valid for ) and for . For strange stars (not valid for strange stars with crust and ). We obtain also an approximate expression for the maximum moment of inertia , where , valid for both neutron stars and strange stars. Applying our formulae to the evaluated values of ICrab, we derive constraints on the mass and radius of the pulsar. A very conservative evaluation of the expanding nebula mass, , yields and 10–14 . Setting the most recent evaluation (“central value”) rules out most of the existing equations of state, leaving only the stiffest ones: , 14–15 .
Key words: dense matter / equation of state / stars: neutron
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.