Physics
Scientific paper
Aug 1972
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1972natur.238..452w&link_type=abstract
Nature, Volume 238, Issue 5365, pp. 452 (1972).
Physics
8
Scientific paper
IF a type I supernova is the result of the explosion of a star with a degenerate nucleus (see, for example, Baglin1) it is likely that a large magnetic field will be present in the radiating region for a short period following the outburst. Depending on the emission process a sufficiently large field could produce a measurable optical circular polarization. For example, for bremsstrahlung in an optically thick but very dilute plasma in an ordered magnetic field of H gauss, the fractional circular polarization in the optical continuum is q ~ 10-9 H (see refs. 2 and 3). If the degenerate progenitor of the supernova is entirely destroyed in the explosion, conservation of magnetic flux dictates that q would reach the limit of detectability (qLIM~3 × 10-6 : HLIM~3,000 G) in only 20 s for either a white dwarf (initial radius r0~109 cm, initial field H0~106 G) or a neutron star (r0~106 cm, H0~1012 G) assuming an expansion velocity of 104 km s-1. If a sizable fragment survives, however, a measurable polarization might be seen for a much longer period. For synchrotron emission smaller fields can produce a detectable polarization. According to Legg and Westfold4 a hypothetical field H~106 G in the Crab nebula would produce q~10% in the visible: since q ~ H½ a polarization qLIM~3 × 10-6 corresponds to HLIM ~ 10-3 G. However, the precise conditions strongly influence5,6 the relations between q and H; the interpretation would therefore be uncertain even if this mechanism were shown to be dominant. The influence of radiative transfer in the dense layers near the star and of a possible fluorescence emission in the outer layers of the shell7 would make the interpretation for the synchrotron process even more difficult.
Kemp James C.
Wolstencroft Ramon D.
No associations
LandOfFree
Optical Polarization of the Supernova in NGC 5253 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 Optical Polarization of the Supernova in NGC 5253, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical Polarization of the Supernova in NGC 5253 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-872865