What causes barrel-shaped supernova remnants?

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

1

Scientific paper

Even from the earliest crude radio maps of 40 years ago, it was apparent that Galactic supernova remnants (SNR) are anything but well-behaved expanding spheres. In particular a significant fraction of SNRs have a bilateral, or ``barrel'', morphology, with a clear axis of reflection symmetry along which there is negligible emission, and with bright flanks on either side. There are numerous theories to explain the appearance of barrel-shaped SNRs, such as the effect of anisotropies in the distribution of supernova ejecta, the structure of the ambient magnetic field, the mass-loss history of the progenitor and the effect of opposed jets or beams from a central source. Three decades of debate have failed to settle the issue, however. Most Galactic SNRs have now been observed in the radio with high resolution and sensitivity, and one can establish a clear bilateral subset of the population. We define such a subset, and find that the symmetry axes of these SNRs are aligned with the Galactic Plane at a high level of statistical significance. This suggests that the Galactic magnetic field is responsible for the appearance of these SNRs at some level. We propose that the ambient field pre-processes the interstellar medium to produce elongated bubbles into which these SNRs expand. This then produces the barrel shape, together with the required alignment. We are in the process of studying the environment of barrel-shaped SNRs in H i\ emission, in order to see if this model is supported by observations.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

What causes barrel-shaped supernova remnants? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with What causes barrel-shaped supernova remnants?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and What causes barrel-shaped supernova remnants? will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-994798

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.