by kovil » Fri Mar 03, 2006 6:00 pm
Found this on a site somewhere and saved it. Best description yet of events thus far.
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"This is a very unusual burst, perhaps the oddest yet seen!
Gamma-rays were detected from this burst for *2000 seconds*, an extremely long time. The burst was faint, with a flat emission (that is, constant brightness) of low-energy or "softer" gamma rays for 280 seconds. Around 200 seconds in it started getting brighter linearly, and at about 290 seconds it emitted higher-energy, "harder" gamma rays for 10 seconds. Eventually, it started to slowly fade away, with gamma rays still being detected 2000 seconds (over 30 minutes) after the initial detection.
Interestingly, Swift detected gamma rays from this same location over a month earlier, on January 17. Spectra taken of this event also show features similar to those seen in a supernova, when a massive star explodes. It seems likely that we are seeing a supernova-GRB connection, a rare event and one that is highly anticipated.
The spectra reveal that this object has a redshift of z=0.0331, corresponding to a very close-by (well, relatively) distance of 450 million light years, practically in our back yard. This is also indicative of a supernova, since a GRB this faint would be expected to be much farther away. In fact, some of the spectral features look like those from SN1998bw, another supernova-GRB event (see
http://www.cosmos.swin.edu.au/entries/s ... ction.html) for more information).
In X-rays, this burst had a long, slow rise in brightness, and faded slowly-- it lasted for at least 3000 seconds. The optical light took 10 hours to reach a maximum as well; most GRBs are seen to be fading in optical light within seconds of the initial burst. Some astronomers thought it might be an unusual object in our own Milky Way Galaxy, but it is located far from where one would expect something like that to be, and the redshift confirms it is extragalactic. There is also a faint galaxy seen near the GRB position.
The supernova/burst has been seen in optical telescopes as small as 0.25 meters (10 inches), making this obtainable by amateur astronomers. It was also detected in radio waves, so this burst has now been studied across the entire electromagnetic spectrum.
All in all, this is another very exciting burst, and more observations will be coming. "
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i too eagerly await more info.
Found this on a site somewhere and saved it. Best description yet of events thus far.
======
"This is a very unusual burst, perhaps the oddest yet seen!
Gamma-rays were detected from this burst for *2000 seconds*, an extremely long time. The burst was faint, with a flat emission (that is, constant brightness) of low-energy or "softer" gamma rays for 280 seconds. Around 200 seconds in it started getting brighter linearly, and at about 290 seconds it emitted higher-energy, "harder" gamma rays for 10 seconds. Eventually, it started to slowly fade away, with gamma rays still being detected 2000 seconds (over 30 minutes) after the initial detection.
Interestingly, Swift detected gamma rays from this same location over a month earlier, on January 17. Spectra taken of this event also show features similar to those seen in a supernova, when a massive star explodes. It seems likely that we are seeing a supernova-GRB connection, a rare event and one that is highly anticipated.
The spectra reveal that this object has a redshift of z=0.0331, corresponding to a very close-by (well, relatively) distance of 450 million light years, practically in our back yard. This is also indicative of a supernova, since a GRB this faint would be expected to be much farther away. In fact, some of the spectral features look like those from SN1998bw, another supernova-GRB event (see http://www.cosmos.swin.edu.au/entries/supernova-gammarayburstconnection/supernova-gammarayburstconnection.html) for more information).
In X-rays, this burst had a long, slow rise in brightness, and faded slowly-- it lasted for at least 3000 seconds. The optical light took 10 hours to reach a maximum as well; most GRBs are seen to be fading in optical light within seconds of the initial burst. Some astronomers thought it might be an unusual object in our own Milky Way Galaxy, but it is located far from where one would expect something like that to be, and the redshift confirms it is extragalactic. There is also a faint galaxy seen near the GRB position.
The supernova/burst has been seen in optical telescopes as small as 0.25 meters (10 inches), making this obtainable by amateur astronomers. It was also detected in radio waves, so this burst has now been studied across the entire electromagnetic spectrum.
All in all, this is another very exciting burst, and more observations will be coming. "
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i too eagerly await more info.