Constraints on the equation of state for neutron stars implied by PSR1957 + 20

摘要: The primary uncertainty in understanding the structure of neutron stars is our lack knowledge equation state condensed matter above nuclear density (3 x 1014 g cm−3). most rapidly rotating stars, millisecond pulsars, may offer a way to probe this region. periods two fastest known PSR1937 + 214 and recently discovered1 PSR1957 20, are within 3% each other, shorter than period any other pulsars by about factor two. This observation substantially strengthens argument that should rotate at limiting frequency for stable stars2,3 We show here if or near their frequencies, masses least 1.4 M⊙, then star must be quite stiff.