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View Full Version : Swift discoveres the brightest ever cosmological X-ray source



Don Alexander
2010-Jul-15, 01:13 AM
Penn State Press Release (http://www.science.psu.edu/news-and-events/2010-news/Burrows7-2010)
Geeked On Goddard (http://geeked.gsfc.nasa.gov/?p=1417)

The second link contains:

"And he saw something very puzzling: For one event, GRB 100621A, the record of its earliest X-ray emission was missing. He’d also received an email from another astronomer who had also noticed the gap."

That, then, would have been me. ;)

Interestingly, the automatic analysis (http://www.swift.ac.uk/xrt_curves/00425151/) "only" registers the highest count rate as ~38,000 ct/s and not 143,000 ct/s. I guess human-in-the-loop is still needed in such cases.

Also, according to the PR, 143,000 > 140 * 10,000...:shifty: Methinks the correct number for the brightest contest X-ray source is 1,000 ct/s (wonder what it is... Crab? Geminga?)

I'll also point out that the PR statement "Surprisingly, although the energy from this burst was the brightest ever in X-rays, it was merely ordinary in optical and ultraviolet wavelengths." is flat out wrong. The afterglow is actually extraordinary, because it is extremely dust-enshrouded, and therefore bright in the NIR while hardly visible in the optical. It's one of the best examples ever of such a reddenend afterglow, and it finds no mention here...

Also, for those in the know, I point out the GRB lies at z = 0.542, which is, in terms of GRBs, quite nearby, which, combined with the fact Swift started observing extremely early, is the reason for the whopping brightness.

Swift
2010-Jul-15, 01:25 AM
I did no such thing!

Oh, you mean the observatory... never mind. ;)

Pretty cool discovery actually.

RussT
2010-Jul-23, 05:09 AM
Penn State Press Release (http://www.science.psu.edu/news-and-events/2010-news/Burrows7-2010)
Geeked On Goddard (http://geeked.gsfc.nasa.gov/?p=1417)

The second link contains:

"And he saw something very puzzling: For one event, GRB 100621A, the record of its earliest X-ray emission was missing. He’d also received an email from another astronomer who had also noticed the gap."

That, then, would have been me. ;)

Interestingly, the automatic analysis (http://www.swift.ac.uk/xrt_curves/00425151/) "only" registers the highest count rate as ~38,000 ct/s and not 143,000 ct/s. I guess human-in-the-loop is still needed in such cases.

Also, according to the PR, 143,000 > 140 * 10,000...:shifty: Methinks the correct number for the brightest contest X-ray source is 1,000 ct/s (wonder what it is... Crab? Geminga?)

I'll also point out that the PR statement "Surprisingly, although the energy from this burst was the brightest ever in X-rays, it was merely ordinary in optical and ultraviolet wavelengths." is flat out wrong. The afterglow is actually extraordinary, because it is extremely dust-enshrouded, and therefore bright in the NIR while hardly visible in the optical. It's one of the best examples ever of such a reddenend afterglow, and it finds no mention here...

Also, for those in the know, I point out the GRB lies at z = 0.542, which is, in terms of GRBs, quite nearby, which, combined with the fact Swift started observing extremely early, is the reason for the whopping brightness.

How long was this burst in seconds...as they are normally listed OR even the T90 is fine?

The GRB blog link I used to use to look these up is no longer working...do you know where I can get the old one...or even the SWIFT one?

Never mind this last part.....geeeezz....I just tried to reload the Swift one and I need to upgrade my IE brouser to 7 or 8 edition and I can't because I still run Windows 98....and I am very hesitant to try firefox because then I will loose ALL my saved links :-(((((((

Thanks

slang
2010-Jul-23, 12:42 PM
....and I am very hesitant to try firefox because then I will loose ALL my saved links :-(((((((

So you'll lose them too if your computer crashes. A windows 98 box? Fear for your harddrive! Be smart, find out now how to backup your bookmarks and other personal stuff. Don't delay to tomorrow. Once you have a proper backup, what's stopping you from trying another browser? Firefox will import favorites from IE, that shouldn't be a problem. But, backup first, backup now. IMHO. :)

RussT
2010-Jul-24, 12:58 AM
So you'll lose them too if your computer crashes. A windows 98 box? Fear for your harddrive! Be smart, find out now how to backup your bookmarks and other personal stuff. Don't delay to tomorrow. Once you have a proper backup, what's stopping you from trying another browser? Firefox will import favorites from IE, that shouldn't be a problem. But, backup first, backup now. IMHO. :)

It is a clean reinstall of windows 98 AE with a whole bunch of other data....but it won't let me copy/paste it.

It is Windows 98 4.10.2222 A

And I have IE 6

Jeff Root said that he is using Windows 98 AE as well,and is using Firefox, but I think when I went to Firefox it said I needed Windows 2000 or better???

Oh, also I have gone to puter stores and tried to get memory 'flash drives' to back up or save much of my 'stuff' on, to clear some harddrive memory, but again they did not have any that were compatible with Windows 98 :-((

I just really need a new system!!!

EricFD
2010-Jul-24, 04:22 PM
......."temporarily blinded the X-ray eye on NASA's Swift space observatory earlier this summer, astronomers now report?" Wow! That's must have been some GRB!

"The correction factor for the X-rays from GRB 100621A was 168 times larger than for a typical gamma-ray burst and 5 times larger than for the brightest burst we previously had seen." That's absolutely incredible! The progenitor of that GRB must have really been something to behold while it still existed.

swampyankee
2010-Jul-24, 04:25 PM
I did no such thing!

Oh, you mean the observatory... never mind. ;)

Pretty cool discovery actually.

Aren't you the main funder for that observatory, hence its name?

slang
2010-Jul-24, 11:11 PM
Aren't you the main funder for that observatory, hence its name?

No, he actually is the observatory. It developed intelligence... . Like V'Ger!

RussT, internal cd/dvd-burners are really cheap. But finding out how to backup shouldn't be in this thread. -> OTB for more questions!

Don Alexander
2010-Jul-25, 12:06 PM
GRBlog GCN collection (http://grblog.org/grblog.php?view=burst&GRB=100621A)
Jochen Greiner's Page (http://www.mpe.mpg.de/~jcg/grb100621A.html)

Rumor has it that mayyybe this is in part due to some analysis problem... I had a look at the detailed X-ray light curve, and it changes count rate by a factor of 15 in just 0.6 seconds... At the same time, the BAT soft gamma-ray emission is doing no such thing. So either we have some really interesting physics going on, or... someone did something wrong in the analysis. Which would be highly embarassing after this press release.

RussT
2010-Jul-25, 10:48 PM
Duration
T90: 63.5839999914169 +/- 1.68360084354133

This is a >2 second to 100 second Burst

That coupled with its nearness...


Also, for those in the know, I point out the GRB lies at z = 0.542, which is, in terms of GRBs, quite nearby, which, combined with the fact Swift started observing extremely early, is the reason for the whopping brightness.

Probably means that this is "Face On" to the Intermediate Black Hole "Collimation/Beam" ;)