Chalmers University | Onsala Space Observatory | 2015 Jan 29
An international team of astronomers led from Chalmers has used the giant radio telescope Lofar to create the sharpest astronomical image ever taken at very long radio wavelengths. Made by observing simultaneously from four countries, including Sweden, the image shows the glowing centre of the galaxy Messier 82 – and many bright remnants of supernova explosions.
Astronomers have taken the sharpest image yet of the sky at very long radio wavelengths. The image shows the centre of the galaxy Messier 82 (M 82), also known as the Cigar Galaxy, 11.5 million light years from Earth. M 82 is forming stars much faster than our galaxy, the Milky Way, and is a favourite object for many astronomers who investigate the evolution of stars and galaxies.
In images taken in visible light, M 82 is a riot of stars, gas and dust. Lofar shows us a completely different scene.
In Lofar’s new extremely sharp image we’re seeing a collection of bright spots, which are most likely supernova remnants, explains Eskil Varenius (Chalmers), who led the international team of scientists behind the new image.
A supernova remnant is a shining shell of shock waves from an exploded star, ploughing into its surroundings. Supernova remnants are huge objects by everyday standards, much larger than the size of our own solar system, but look small from a distance.
This galaxy is millions of light years away, and each remnant can be as little as a few light years across. We need extremely sharp images to study them, says Eskil Varenius. ...
Subarcsecond international LOFAR radio images of the M82 nucleus at 118 MHz and 154 MHz - E. Varenius et al
- arXiv.org > astro-ph > arXiv:1411.7680 > 27 Nov 2014