SPECIAL RELATIVISTIC JET COLLIMATION BY INERTIAL CONFINEMENT

We present an explicit numerical method to handle problems in special, relativistic hydrodynamics. This method is a special relativistic exte nsion of a Roe solver method for nonrelativistic flow. The method is u sed to simulate the collimation of an initially spherical outflow by a thickened disk (i.e. collimation by inertial confinement). Previous n onrelativistic results indicated that this is a mechanism to form jets . Here we show that this mechanism can also generate relativistic jets . The highest Lorentz factor achieved in these simulations is 15. We d iscuss the differences between the relativistic and nonrelativistic fl ow.