We consider the distributed-order space-time fractional heat type equation \begin{document}$ \mathbb{D}^{(\nu)}u(t, x) = -(-\Delta)^{\alpha/2}u(t, x), \ t>0, x\in D, $\end{document} where$ \mathbb{D}^{(\nu)} $ is derivative based on Caputo time-fractional derivative, -(-\Delta)^{\alpha/2} generator of an isotropic stable process for \alpha\in(0, 2] $, D a bounded domain in \mathbb{R}^d and \...