Radio Detection of the Supernova Remnant RX J0852.0−4622

The X-ray source RX J0852.0-4622 has been recently proposed as a candidate for a young nearby supernova remnant on the basis of its X-ray (≥1.3 keV) morphology, inferred internal shock velocities, and the clear detection of 44 Ti emission lines. In this Letter, we report its detection at radio wavelengths (2.4 and 1.42 GHz). The radio images match the X-ray morphology very well and show a limb-brightened source with some elongated features protruding from the outer shell. These features could be explosion fragments similar to those detected in the Vela supernova remnant. At radio frequencies the source appears to be nonthermal, with an index ⟨α⟩ ~ -0.3. This synchrotron emission seems to extend up to X-ray energies, implying the existence of very high energy electrons locally accelerated in the remnant.