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OnderzoekVan Swinderen Institute

Physics: Prof. M. Mendez: Mass, radii, and the internal composition of neutron stars


18 October 2007 FWN-Building 5111.0080, Nijenborgh 4, 9747 AG, Groningen
Speaker: Physics: Prof. Mariano Mendez
Affiliation: Kapteyn Institute, University of Groningen
Title: Mass, radii, and the internal composition of neutron stars
Date: 18-10-2007
Start: 16.00
Location: FWN-Building 5111.0080


In the interior of neutron stars, density can reach up to 10 times the nuclear density, a regime in which no laboratory measurement exists. Besides neutrons, protons, electrons and muons, at those high densities the physics of strong nuclear interactions predicts the existence of other more exotic particles, like strangeness-bearing baryons, pions and kaon condensates, or even deconfined quarks. Neutron stars offer the only possibility, since the Big Bang, to find those particles in nature.

Measurements of the masses and radii of neutron stars constrain the internal constitution, the so-called equation of state, of the neutron star.

 The equation of state of neutron-star matter is intimately related to the physics of the strong interactions between fundamental particles, and therefore it is of great relevance in high-energy and particle physics; it determines the properties and governs the stability of neutron stars; it is central to the dynamics of supernovae explosions; it is a key ingredient in models of neutron star--neutron star mergers that may be the progenitors of certain type of gamma-ray-burst sources, and sources of strong gravitational waves; it provides the necessary framework to calculate the cooling processes that take place in the interior of neutron stars which, compared to observed neutron star temperatures, can be used to estimate the neutron star ages. Since the whole structure of a neutron star is set by the equation of state at these high densities, measurements of neutron stars masses and radii can provide information on the equation of state, and on the physical makeup of neutron stars.

 In this colloquium I will review the current status of this topic.

Last modified:12 September 2014 11.21 a.m.