  We derive analytical results for various quantities related to the
excited-state quantum phase transitions in a class of Dicke superradiance
models in the semiclassical limit. Based on a calculation of a partition sum
restricted to Dicke states, we discuss the singular behavior of the derivative
of the density of states and find observables like the mean (atomic) inversion
and the boson (photon) number and its fluctuations at arbitrary energies.
Criticality depends on energy and a parameter that quantifies the relative
weight of rotating versus counter-rotating terms, and we find a close analogy
to the logarithmic and jump-type non-analyticities known from the
Lipkin-Meshkov-Glick model.
