  The nuclear modification factor $R_{AA}$ for $\pi_0$ production in Au+Au
collisions at $\sqrt{s}=200$ AGeV is calculated, and studied at high transverse
momenta $p_T$. The soft thermalized nuclear medium is described within the
framework of relativistic ideal three-dimensional hydrodynamics. The energy
loss of partonic jets is evaluated in the context of gluon bremsstrahlung in
the thermalized partonic matter. We provide a systematic analysis of the
azimuthal asymmetry of $\pi_0$ suppression at high $p_T$ in central and
non-central collisions, at mid and forward rapidity. The determination of
$R_{AA}$ as a function of $p_T$, at different azimuthal angles, and different
rapidities makes for a stringent test of our theoretical understanding of jet
energy loss over a variety of in-medium path lengths, temperatures and initial
partonic jet energies. This lays the groundwork for a precise tomography of the
nuclear medium.
