论文标题
弯曲时空中紧凑物体的热辐射
Thermal Radiation from Compact Objects in Curved Space-Time
论文作者
论文摘要
我们在这里强调了一个事实，即球形对称的紧凑型星形辐射热辐射的光度较高，而$（1+z {\ rm b}）^2 $与相应的平面时空情况相比，在$ z_ {$ z_ {\ rm b} $中是表面上的graverational gravitational gravitation gravity redshipt comctact and comptict ock comctact and comptict sartift and comptict sartift and comctact。特别是，我们强调的是，如果确实在每个点沿着各个正常方向发射热辐射，那么即使紧凑的对象位于其{\ em photon sphere}之内，$（1+z _ {\ rm b}）^2 $的增量因素也保持不变。由于规范的中子星的$ z {\ rm b} \大约0.1 $，因此中子星表面的实际X射线光度可能是$ \ sim 20 \％$，比忽略此处描述的一般相对论效应所解释的内容。对于仅受各向同性压力支持的静态紧凑对象，紧凑性受到buchdahl限制$ z _ {\ rm b} <2.0 $的限制。但是，对于由各向异性压力支持的紧凑对象，$ z {\ rm b} $甚至更高（$ z _ {\ rm b} <5.211 $）。此外，原则上，可能存在具有$ z {\ rm b} \ gg 1 $的超压缩对象。因此，此处描述的一般相对论效应对于来自某些超压缩物体的热辐射的研究可能非常重要。
We highlight here the fact that the distantly observed luminosity of a spherically symmetric compact star radiating thermal radiation isotropically is higher by a factor of $(1+z_{\rm b})^2$ compared to the corresponding flat space-time case, where $z_{\rm b}$ is the surface gravitational redshift of the compact star. In particular, we emphasize that if the thermal radiation is indeed emitted isotropically along the respective normal directions at each point, this factor of increment $(1+z_{\rm b})^2$ remains unchanged even if the compact object would lie within its {\em photon sphere}. Since a canonical neutron star has $z_{\rm b} \approx 0.1$, the actual X-ray luminosity from the neutron star surface could be $\sim 20 \%$ higher than what would be interpreted by ignoring the general relativistic effects described here. For a static compact object, supported by only isotropic pressure, compactness is limited by the Buchdahl limit $z_{\rm b} < 2.0$. However, for compact objects supported by anisotropic pressure, $z_{\rm b}$ could be even higher ($z_{\rm b} < 5.211$). In addition, in principle, there could be ultra-compact objects having $z_{\rm b} \gg 1$. Accordingly, the general relativistic effects described here might be quite important for studies of thermal radiation from some ultra-compact objects.
