propagating into the interstellar medium (ISM) or the circumstellar medium is thought to accelerate particles (electrons and protons), which gain energy through first order Fermi acceleration [@Bell:1978] also known as the Diffusive Shock Acceleration mechanism (DSA). In core-collapse SNRs, a very fast rotating and highly magnetized pulsar can give rise to a PWN, in which electrons and positrons from the pulsar wind are re-accelerated to relativistic energies at a termination shock. These Galactic accelerators have mostly been studied independently while in case of core-collapse SNRs, the SNR, the PWN and the pulsar are part of the same object. However, for systems with angular sizes smaller or comparable to the instrument point-spread function (PSF), it can be difficult to assess the origin of the emission, in particular at $\gamma$-ray energies where the angular resolution is comparatively much larger than in the radio and X-ray ranges. Although it can be challenging to understand their origin, these $\gamma$ rays allow probing the population of high-energy particles, such as accelerated electrons interacting with the Cosmic Microwave Background (CMB) or other target photons by Inverse Compton (IC) scattering, and also accelerated protons interacting with gas that produce neutral pions which decay into $\gamma$ rays. Morphological 