  We study Hawking radiation on the quantum spacetime generated by a quantum
ingoing null shell in the 2d theory proposed by
Callan-Giddings-Harvey-Strominger (CGHS). The quantum spacetime is a
superposition of classical geometries with uncertainty in position and momentum
of the collapsing shell. The Hawking radiation spectrum is computed, revealing
a non-thermal behavior for finite time as well as a dependence on the shell's
physical degrees of freedom. Hawking radiation's dependence on the collapsing
shell becomes irrelevant in the late time approximation as we reach $i^+$ since
the radiation's temperature depends exclusively on the cosmological constant.
However, we argue that the information of the quantum state of a collapsing
shell can be read from the Hawking radiation if we perform measurements at
$\mathcal{I_R^+}$ taking into account backreaction effects.

General Relativity and Quantum Cosmology