Title: Physics of compact stars - recent developments

Speaker:  Prof. David Blaschke

University of Wroclaw, Poland and JINR Dubna, Russia

Date: 2 September 2011

Time: 14:30

Location: Conference Hall, Physics Department, Yerevan State University

Abstract:
Compact stars provide insights into the nature of nuclear matter at
densities exceeding that of atomic nuclei (~2.4 10^14 g/cm^3).
In particular any extreme value of observables such as radius, mass,
and temperature, is likely to improve our understanding of the
properties of cold and dense matter substantially.
In this seminar, two spectacular observations of this kind made in
2010 will be explained together with their possible implications:
1) The measurement of the Shapiro delay of pulses from
PSR J1614-2230, which allowed the determination of its mass to
1.97+/-0.04 M_sun and makes him the heaviest neutron star ever
observed with sufficient accuracy and confidence [1];
2) The determination of the extreme cooling rate (4% drop
of surface temperature within 10 years) for the youngest neutron star
in our galaxy, situated in the supernova remnant Cassiopeia A [2,3].

[1] P. Demorest et al., Nature 467, 1081 (2010)
[2] C.O. Heinke and W.C.G. Ho, Astrophys. J. 719, L45 (2010)
[3] W.C.G. Ho and C.O. Heinke, Nature 462, 71 (2009)