Neutron Stars and their Radii

中子星是宇宙中已知的最致密的天体。它们的质量约为太阳的质量，大小约为15-30公里，这是我们从对物质在如此高的密度下--即在原子核密度以上--如何表现的理论计算中得知的。 然而，这些计算中的粒子物理和计算本身都是不确定的，这导致了它们大小的2倍范围。如果我们能够准确地测量中子星的大小，我们就可以倒着解决这个问题：推导出在核密度以上运行的粒子物理学。 这项提议的重点是观测工作：(1)发现适合测量其半径的中子星--即具有弱磁场，其发射由热的neturon星本身主导的中子星；(2)获得测量以准确确定这些中子星的大小。 此外，这项提议还包括与一个扩展的国际小组合作，发现和表征最高红移伽马射线暴的工作。最后，这项提议还支持领先的短通知天体物理学出版物《天文学家电报》。

Neutron stars are the most compact objects known to exist in the universe. They have about the mass of the sun within a size of perhaps 15-30 km, which we know from theoretical calculations of how matter behaves at such high densities -- that is, at and above the density of an atomic nucleus. However, both the particle physics which goes into these calculations, and the calculations themselves are uncertain, giving rise to that factor of 2 range for their size. If we could accurately measure the sizes of neutron stars, we could work the problem backwards: to derive the particle physics which operates at and above nuclear density. This proposal is focussed around observational work to: (1) discover neutron stars suitable for measuring their radii -- that is, which have weak magnetic fields, and whose emission is dominated by the hot neturon star itself; (2) obtain measurements to accurately determine the sizes of these neutron stars. In addition, this proposal includes work associated with discovering and characterizing the highest redshift gamma-ray bursts, in collaboration with an extended, international group. Finally, this proposal also supports the leading short-notice astrophysical publication, The Astronomer's Telegram.