Bogoliubov coefficients of 2D charged black holes

We exactly calculate the thermal distribution and temperature of Hawking ra diation for a two-dimensional charged dilatonic black hole after it has set tled down to an "equilibrium" state. The calculation is carried out using t he Bogoliubov coefficients. The background of the process is furnished by a preexisting black hole and not by collapsing matter as considered by Giddi ngs and Nelson for the case of a Schwarzschild black hole. Furthermore, the vanishing of the temperature and/or the Hawking radiation in the extremal case is obtained as a regular limit of the general case. (C) 2001 Elsevier Science B.V. All rights reserved.