Friday, April 16, 2010
RADIO SIGNALS, A MICROQUASAR, OR WHAT?
Here at Doc40 we’re big fans of anything weird coming from out of the cosmos. This should more than qualify.
“There is something strange in the cosmic neighbourhood. An unknown object in the nearby galaxy M82 has started sending out radio waves, and the emission does not look like anything seen anywhere in the universe before. "We don't know what it is," says co-discoverer Tom Muxlow of Jodrell Bank Centre for Astrophysics near Macclesfield, UK. The thing appeared in May last year, while Muxlow and his colleagues were monitoring an unrelated stellar explosion in M82 using the MERLIN network of radio telescopes in the UK. A bright spot of radio emission emerged over only a few days, quite rapidly in astronomical terms. Since then it has done very little except baffle astrophysicists. It certainly does not fit the pattern of radio emissions from supernovae: they usually get brighter over a few weeks and then fade away over months, with the spectrum of the radiation changing all the while. The new source has hardly changed in brightness over the course of a year, and its spectrum is steady. Yet it does seem to be moving – and fast: its apparent sideways velocity is four times the speed of light. Such apparent "superluminal" motion has been seen before in high-speed jets of material squirted out by some black holes. The stuff in these jets is moving towards us at a slight angle and travelling at a fair fraction of the speed of light, and the effects of relativity produce a kind of optical illusion that makes the motion appear superluminal. Could the object be a black hole? It is not quite in the middle of M82, where astronomers would expect to find the kind of supermassive central black hole that most other galaxies have. Which leaves the possibility that it could be a smaller-scale "microquasar".” (Click here for more)
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The secret words are Warp and Speed
Posted by Mick at 4/16/2010 04:49:00 PM