Supernova remnant in the Small Magellanic Cloud

This colour composite image represents the very first infrared observation of a supernova remnant (called B0104-72.3) in the Small Magellanic Cloud, a small galaxy neighbouring the Milky Way. It is visible from the southern hemisphere and it is located at a distance of 200 000 light years from the Earth. The object was observed by AKARI’s Near- and Mid-Infrared Camera (IRC) at wavelengths of 3, 4, 7 and 11 micrometres. The pair of arc-like structures forming the spatial extent of the supernova remnant cover approximately 60x100 light years and the white bar in the bottom-left corner indicates a length of 30 light years.

In the final stage in the life of stars much heavier than our own Sun, a supernova explosion ejects matter into interstellar space, creating a supernova remnant. The matter ejected consists of newly synthesized elements created inside the star’s core. The catastrophic explosion disturbs interstellar material creating shock waves over great distances, thus making supernovae essential contributors in the internal evolution of galaxies.

B0104-72.3 is a well-known supernova remnant that has been observed with radio and X-rays, (although not particularly bright at these wavelengths). Infrared observations help trace the interaction between the supernova remnant and the interstellar medium, but this understanding has until recently been limited due to the lack of data.

B0104-72.3 was observed by AKARI at four different infrared wavelengths, the intensity ratios of which reveal the presence of a shock at the interaction between the expanding remnant and the surrounding molecular clouds. This implies that the precursor was a high-mass star. In this manner, observations with AKARI are expected to play a key role in understanding the evolution of interstellar material through studies of interaction processes with the supernova remnant.