  Theorems on the emission of massless scalar particles by the CGHS black hole
are presented. The convergence of the mean number of particles created
spontaneously in an arbitrary state is studied and shown to be strongly
dependent on the infrared behavior of this state. A bound for this quantity is
given and its asymptotic forms close to the horizon and far from the black hole
are investigated. The physics of a wave packet is analysed in some detail in
the black-hole background. It is also shown that for some states the mean
number of created particles is not thermal close to the horizon. These states
have a long queue extending far from the black hole, or are unlocalised in
configuration space.
