An RGB image above of the G11.2–0.3 supernova remnant comparing the 6cm ATCA radio map (green), 2.7-9.0 keV Chandra X-ray map (red), and 0.5-2.0 keV Chandra X-ray map (blue). The magenta circle, cyan box, and white elliptical annulus indicate the central pulsar, radio jet and torus, respectively. From Zhang et al. 2025

After a massive star undergoes a supernova (SN) explosion, it may leave behind a compact neutron star inside a supernova remnant (SNR), which may also be observed as a pulsar, emitting periodic signals towards the Earth due to its rotation. The slowing of the pulsar’s rotation powers this pulsed emission as well as an outflow of particles in a pulsar wind (PW). This wind inflates a magnetic nebula full of accelerated high-energy particles inside, forming a pulsar wind nebula (PWN). While pulsar wind nebulae (PWNe) are important sources for understanding galactic high-energy processes, it is unclear how high-energy particles in PWNe are accelerated and transported. A lack of radio counterparts for X-ray PWNe (the proposed acceleration sites) has made interpretation problematic.

Zhang et al. present 3, 6, and 16 cm high-resolution observations of G11.2−0.3 PWN with the ATCA which uniquely show morphological similarity with its X-ray PWN — a torus/jet feature. The spectral indices of the radio torus and jet are around -0.1, while the spectral break between radio and X-ray spectra in the jet region implies particle acceleration mechanisms other than a diffusive shock acceleration. Polarization results suggest an equipartition magnetic field strength in the jet of below 100 micro-gauss. The RGB image above of G 11.2–0.3 SNR compares the 6cm ATCA radio map (green), 2.7-9.0 keV Chandra X-ray map (red), and 0.5-2.0 keV Chandra X-ray map (blue) with smoothed FWHMs of around 5 arcseconds. The magenta circle, cyan box, and white elliptical annulus indicate the central pulsar, radio jet and torus, respectively. The white dashed circle is used as a background region for flux measurements of PWN structures.