Fourier Modeling of the Radio Torus Surrounding Supernova 1987A

Details Fourier Modeling of the Radio Torus Surrounding Supernova 1987A Fourier Modeling of the Radio Torus Surrounding Supernova 1987A

2008-05-27

arxiv.org/abs/0805.4195v1

Astronomy and Astrophysics

Astrophysics

accepted by ApJ, 11 figures, some have been scaled down in resolution

Scientific paper

10.1086/590330

We present detailed Fourier modeling of the radio remnant of Supernova 1987A, using high-resolution 9 GHz and 18 GHz data taken with the Australia Telescope Compact Array over the period 1992 to 2008. We develop a parameterized three-dimensional torus model for the expanding radio shell, in which the emission is confined to an inclined equatorial belt; our model also incorporates both a correction for light travel-time effects and an overall east-west gradient in the radio emissivity. By deriving an analytic expression for the two-dimensional Fourier transform of the projected three-dimensional brightness distribution, we can fit our spatial model directly to the interferometric visibility data. This provides robust estimates to the radio morphology at each epoch. The best-fit results suggest a constant remnant expansion at 4000 +/- 400 km/s over the 16-year period covered by the observations. The model fits also indicate substantial mid-latitude emission, extending to 40 degree on either side of the equatorial plane. This likely corresponds to the extra-planar structure seen in H$\alpha$ and Ly$\alpha$ emission from the supernova reverse shock, and broadly supports hydrodynamic models in which the complex circumstellar environment was produced by a progression of interacting winds from the progenitor. Our model quantifies the clear asymmetry seen in the radio images: we find that the eastern half of the radio remnant is consistently ~40 brighter than the western half at all epochs, which may result from an asymmetry in the ejecta distribution between these two hemispheres.

Affiliated with

Also associated with

No associations

Rating

Fourier Modeling of the Radio Torus Surrounding Supernova 1987A 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 Fourier Modeling of the Radio Torus Surrounding Supernova 1987A, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fourier Modeling of the Radio Torus Surrounding Supernova 1987A will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-274217