摘要
黑洞周围的高度时空弯曲是使从其附近发出的喷流趋于弥散的一种机制。然而在大多数情况下,流体自身的压强能够克服引力效应,从而导致喷流的准直。当喷流在远离黑洞的空间传播时,为了保持其准直性,外部媒质的压强随径向距离r增大必须下降得不比r^(-3)更快。
Spacetime curvature around a black hole is a mechanism decollimating a jet produced in the region near the hole. For fluid jets, in most cases pressure effects can dominate over gravitational effects, thus lead to an overall collimation of the flow. In order to keep a jet flowing in the region far away from the black hole, the external pressure Pe of the medium should not drop with increasing radial distance, r, faster than a relation of the type Pe∝r-3 would imply.
