Supernova Remnants in the Multi-Messenger Era

This is an exciting time for the discovery of supernova remnants (SNRs) in our and other nearby galaxies. SNRs reflect a major process in the elemental enrichment of the ISM. The study of this interaction in different domains including gamma-ray, radio, optical, IR and X-ray, allow a better understanding of these objects and their environments. Nearby galaxies offer an ideal laboratory, since they are near enough to be resolved, yet located at relatively known distances. The emission from non-thermal MeV to GeV electrons makes SNRs bright radio sources, while non-thermal X-rays have been confirmed for a number of young Galactic SNRs indicating the existence of TeV electrons. Similarly, highly relativistic particles have been detected in superbubbles (e.g., 30 Dor C), which are interstellar structures created by the combination of stellar winds of massive stars and their supernovae. However, the underlying physics such as particle injection, magnetic field configuration and amplification, and the escape of particles from the shock regions requires further investigation. Magnetic fields in SNRs and superbubbles are most likely a complex mixture of interstellar magnetic fields, relic fields of the progenitor, fields modified and enhanced by turbulence in the shock regions, and fields excited by relativistic particles. Therefore, various high spatial resolution, high sensitivity, and high spectral resolution observations are necessary to address these %issues. SKA pathfinders' observations in radio at low frequencies with %high sensitivity will detect new SNRs in our Galaxy and the MCs, which %are either old and too faint, young and too small, or located in a too %confusing environment and have thus not been detected yet. In addition, %the SKA pathfinders' observations will also allow high-resolution %polarimetry and are key to the study of the energetics of accelerated %particles as well as the magnetic field strength and %configurations. Gamma-ray studies provide answers to the long-standing %question in high energy astrophysics: Where do cosmic rays come from? %The gamma ray emission seen from some middle-aged SNRs is now known to be from distant populations of cosmic-rays (probably accelerated locally) interacting with gas, but there is still much work to be done in accounting for the Galactic cosmic-ray flux. Young PeV gamma-ray supernova remnants require different techniques to address the question of cosmic-ray acceleration. The CTA will allow us to do this. I will present an overview of our ongoing multi-wavelength studies of the young (and some not-so-young) SNRs: LMCSNR0509-69, N103B, RX J1713.7-3946, HESSJ1731-347, Vela Jr, HESS J1534-571, G23.1+0.2 and others. Finally, I will present our strategies for the next 10 years on how to observe SNRs with the next generation of instruments - from ASKAP/MWA2 via eROSITA to CTA.