GRB 140903A: Chandra finds evidence for violent stellar merger

July 14, 2016, Chandra X-ray Center
Credit: X-ray: NASA/CXC/Univ. of Maryland/E. Troja et al, Optical: Lowell Observatory's Discovery Channel Telescope/E.Troja et al. Illustration: NASA/CXC/M.Weiss

Gamma-ray bursts, or GRBs, are some of the most violent and energetic events in the Universe. Although these events are the most luminous explosions in the universe, a new study using NASA's Chandra X-ray Observatory, NASA's Swift satellite and other telescopes suggests that scientists may be missing a majority of these powerful cosmic detonations.

Astronomers think that some GRBs are the product of the collision and merger of two neutron stars or a neutron star and a black hole. The new research gives the best evidence to date that such collisions will generate a very narrow beam, or jet, of gamma rays. If such a narrow jet is not pointed toward Earth, the GRB produced by the collision will not be detected.

Collisions between two neutron stars or a neutron star and black hole are expected to be strong sources of gravitational waves that could be detected whether or not the jet is pointed towards the Earth. Therefore, this result has important implications for the number of events that will be detectable by the Laser Interferometry Gravitational-Wave Observatory (LIGO) and other gravitational wave observatories.

On September 3, 2014, NASA's Swift observatory picked up a GRB - dubbed GRB 140903A due to the date it was detected. Scientists used optical observations with the Gemini Observatory telescope in Hawaii to determine that GRB 140903A was located in a galaxy about 3.9 billion light years away, relatively nearby for a GRB.

The large panel in the graphic is an illustration showing the aftermath of a neutron star merger, including the generation of a GRB. In the center is a compact object - either a black hole or a massive neutron star - and in red is a disk of material left over from the merger, containing material falling towards the compact object. Energy from this infalling material drives the GRB jet shown in yellow. In orange is a wind of particles blowing away from the disk and in blue is material ejected from the compact object and expanding at very high speeds of about one tenth the speed of light.

The image on the left of the two smaller panels shows an optical view from the Discovery Channel Telescope (DCT) with GRB 140903A in the middle of the square and a close-up X-ray view from Chandra on the right. The bright star in the optical image is unrelated to the GRB.

The gamma-ray blast lasted less than two seconds. This placed it into the "short GRB" category, which astronomers think are the output from neutron star-neutron star or black hole-neutron star collisions eventually forming either a black hole or a neutron star with a strong magnetic field. (The scientific consensus is that GRBs that last longer than two seconds result from the collapse of a massive star.)

About three weeks after the Swift discovery of GRB 140903A, a team of researchers led by Eleonora Troja of the University of Maryland, College Park (UMD), observed the aftermath of the GRB in X-rays with Chandra. Chandra observations of how the X-ray emission from this GRB decreases over time provide important information about the properties of the jet.

Specifically, the researchers found that the jet is beamed into an angle of only about five degrees based on the X-ray observations, plus optical observations with the Gemini Observatory and the DCT and radio observations with the National Science Foundation's Karl G. Jansky Very Large Array. This is roughly equivalent to a circle with the diameter of your three middle fingers held at arms length. This means that astronomers are detecting only about 0.4% of this type of GRB when it goes off, since in most cases the jet will not be pointed directly at us.

Previous studies by other astronomers had suggested that these mergers could produce narrow jets. However, the evidence in those cases was not as strong because the rapid decline in light was not observed at multiple wavelengths, allowing for explanations not involving jets.

Several pieces of evidence link this event to the merger of two , or between a neutron star and black hole. These include the properties of the gamma ray emission, the old age and the low rate of stars forming in the GRB's host galaxy and the lack of a bright supernova. In some previous cases strong evidence for this connection was not found.

New studies have suggested that such mergers could be the production site of elements heavier than iron, such as gold. Therefore, the rate of these events is also important to estimate the total amount of heavy elements produced by these mergers and compare it with the amounts observed in the Milky Way galaxy.

A paper describing these results was recently accepted for publication in The Astrophysical Journal and is available online.

Explore further: Did a gamma ray burst accompany LIGO's gravity wave detection?

More information: An achromatic break in the afterglow of the short GRB 140903A: evidence for a narrow jet, arXiv:1605.03573 [astro-ph.HE] arxiv.org/abs/1605.03573

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cantdrive85
2.1 / 5 (14) Jul 15, 2016
Chandra found a GRB, the claims that it signifies merging fairy tales is pure fantasy.

"We have to learn again that science without contact with experiments is an enterprise which is likely to go completely astray into imaginary conjecture." Hannes Alfvén
Captain Stumpy
3.9 / 5 (11) Jul 15, 2016
Chandra found a GRB, the claims that it signifies merging fairy tales is pure fantasy
@cantthink
well, considering the quote you gave from your hero...

where is your evidence and experimental validation that it is a "fairy tale" or "pure fantasy"?

if you're making this claim, as you did above, then that means, per your quoting of H.Alfven, that you are making a statement you can prove with evidence, right?

because otherwise you are just making a comment that is "completely astray into imaginary conjecture", per your own criteria

of course, to be considered science at all, your claims and belief must also adhere to the scientific method
https://en.wikipe...c_method

and given you can't adhere to said scientific method, as proven in various threads as well as the failure of Mainstream to accept the eu bullsh*t, then it is, by definition, pseudoscience
https://en.wikipe...oscience

therefore, using logic, your claims are crap
wduckss
1.4 / 5 (9) Jul 15, 2016
Connecting the body generates their growth. This is a normal occurrence in the universe and do not unfolds itself at the suggested, manner regulated by Article. Also event, which is described, represents something else also represented in the processes in the universe:
"Essentially, it is the same event that takes place when an object arrives from the outside vertically to one of the stellar poles, hits the eye of a cyclone and penetrates deep into the Interiority of the old. If"
http://www.svemir...rocesses (Cyclone instead of black holes)
Captain Stumpy
4 / 5 (8) Jul 15, 2016
@ILLITERATE Bschit
try reading that again:
if you and the idiot claim that something can't be factual, then, by the idiot cantthink's reasoning and his quote, it must be supported by empirical evidence in the form of experiments that demonstrate a refute to said physics
as he stated
claims that it signifies merging fairy tales is pure fantasy
per his own statements, that means he can prove it is fantasy

IOW- because he stated it as fact it must be, per his own claims, validated with experimental evidence

so where is his/your evidence?
I can tell you... there isn't any!

just like all of your own claims, it is a personal belief based upon a delusional religious like adherence to anything against the mainstream because of the Dunnig-Kruger belief that you can answer everything with your own pseudoscience

you're not a skeptic, your a trolling idiot incapable of comprehending even the basics

the rest of your post is BS red-herring false claims
Steve 200mph Cruiz
4.6 / 5 (10) Jul 15, 2016
Cantdrive Bschot,

Telescopes are functional tools.
We also have observed back holes as well.

I know you guys think that math is gay, but it worked well enough for us to discover Neptune, it works well enough for GPS, it matches up with atomic clocks perfectly fine.

By denying black holes, you are denying the thing that makes everyday proven technologies even work.
For all intensive purposes, Einstein is right.
Black holes have an incomplete understanding, but relativity doesn't describe what a black hole is, just what the space around it is doing.

Also gravitational waves have been detected, and are now a part of modern astronomy and will be for the rest of civilization, get with it.
rkolter
5 / 5 (10) Jul 15, 2016
that you are making a statement you can prove with evidence, right?

Right, nobody has ever observed it, that is evidence that it does not exist


This is so wrong it is beyond wrong.

We have in fact directly observed neutron stars. Here's just one of plenty of examples:
http://chandra.ha...rj11014/

Lack of observation is not evidence. The tooth fairy may not exist; but you would not argue she may not exist because she has never been seen. You would argue that you stayed up late as a child and caught a human, not a fairy, replacing your tooth with money. You would argue by providing a counter observation, not with a lack of observation.

Da Schneib
4.6 / 5 (10) Jul 15, 2016
You would argue by providing a counter observation, not with a lack of observation.
A good tagline for this is, "Absence of evidence is not evidence of absence."

The thing here is, in fact there isn't an absence of evidence. Not only have we observed neutron stars, we've observed a whole bunch of them, and we even have been able to divide them into classes, like pulsars, magnetars, "cold" neutron stars, and neutron star binaries. The evidence is therefore quite strong. And we all know what it means when someone denies evidence.

Good post, @rkolter. 5 stars from me.
cantdrive85
1.8 / 5 (10) Jul 15, 2016
Telescopes are functional tools.

Yep, but the people theorizing on what they are looking at are non-functional tools.
We also have observed back holes as well.

By the very definition of the fictional black hole, it is impossible to directly observe them.
By denying black holes, you are denying the thing that makes everyday proven technologies even work.

LOL!
For all intensive purposes,

What's an intensive purpose? I think you mean "intents and purposes".
Black holes have an incomplete understanding,

BH's violate all known physics, that should be a clue for you clowns.
Also gravitational waves have been detected,

Confirmation bias, no more no less.
cantdrive85
1.7 / 5 (11) Jul 15, 2016
We have in fact directly observed neutron stars. Here's just one of plenty of examples:

We have observed what astrophysicists deem as neutron stars, regardless of the fact that they too violate well understood physics based upon laboratory research.
Lack of observation is not evidence

Tell that to those who deny the existence and primary importance of electric fields and electric currents in plasmas.
You would argue by providing a counter observation, not with a lack of observation.

Then none of you have adequately studied Plasma Cosmology, if you'd had then you'd understand that it is not necessary to invent 96% more fairy tales to account for reality.
Da Schneib
4.5 / 5 (8) Jul 15, 2016
Confirmation bias
You don't even know what confirmation bias is, and that's obvious from this usage of it.

You just toss buzz-words around like they mean something, and then shout insults when someone points it out.

No evidence = you're lying. Simple as that, @CD86.
cantdrive85
1.7 / 5 (11) Jul 15, 2016
No evidence = you're lying. Simple as that, @CD86

Doesn't matter if I show evidence, as I did over in the wobbly BH thread. You just conveniently ignore it and blather on with your pseudoscientific mumbo jumbo.
Da Schneib
4.5 / 5 (8) Jul 15, 2016
You just argued against using evidence to support your position, @CD86, which is why no one believes you. There is no excuse for it, there is no possible justification for it, and the fact that you don't have any reliable evidence or any demonstrable ability to predict anything, and the mainstream paradigm moves from one successful prediction to another, is exactly what the problem is with your religion.
cantdrive85
1.8 / 5 (10) Jul 16, 2016
The justification is that you just ignore it, I'm not interested in pissing into the wind. When you get off your knees at the alter of Einstein you might finally see passed the low wall of pseudoscience. The mainstream paradigm moves forward by inventing one ad hoc patch after another. It'seems at about 96% invented fairytales now, and growing. But that's about right considering you believe 90% adjustments qualify for proof.
Da Schneib
4.4 / 5 (7) Jul 16, 2016
The justification is that you just ignore it
No, I answered it; this is denialist tactic number 3847 which is to accuse your opposition of that which you are guilty of. It's a rhetorical tactic, and one we see all the time in conservative politics.

You chose to ignore my answer. You're welcome to your opinion, but if it denies the facts it's a lie. Simple as that. If you attempt to ignore the facts, and then try to justify it by making an unsubstantiated accusation of my doing so, everyone can see that and knows what it means. Humans have millions of years of experience at detecting treachery.
cantdrive85
1.8 / 5 (10) Jul 16, 2016
Yep, I saw how you changed the subject and acknowledged it was a different mission. It wasn't the 3/4 of a billion dollar boondoggle that you lauded. You're either a moron or a liar, and most likely both.
Da Schneib
4.2 / 5 (5) Jul 16, 2016
I saw how you changed the subject and acknowledged it was a different mission
Ummmm, where exactly do you claim I did this, @CD86?

You know, that whole evidence thing.
cantdrive85
1.8 / 5 (10) Jul 16, 2016
It's all right there in the next paragraph...

You know, that whole moronic liar thing.
Da Schneib
4.3 / 5 (6) Jul 16, 2016
It's all right there in the next paragraph...
So, no quote where I did this. Again.

Lying again, I see, @CD86.
Enthusiastic Fool
4 / 5 (8) Jul 16, 2016
@CD
I'm not interested in pissing into the wind.


When you argue without evidence that's precisely what you are doing--pissing all over your own argument.
jonesdave
3.5 / 5 (8) Jul 17, 2016
@CD
I'm not interested in pissing into the wind.


When you argue without evidence that's precisely what you are doing--pissing all over your own argument.


TBF, EF, our EU idiots have a bit of a problem with Chandra. They don't like it. After all, it was Chandra, along with SWIFT, that showed that the idiot Thornhill's claims of an electric flash at Tempel 1 was b*ll*cks. Don't expect them to suddenly grasp basic science. Not going to happen.
Links available, should the hard of thinking require them.
Maggnus
3.7 / 5 (3) Jul 19, 2016
BLAHAHAHAHA!!!!

Use of multiple exclamation marks, especially in combination with caps, is a clear sign of mental instability.

IS NOT!!!!
Maggnus
4 / 5 (4) Jul 19, 2016
For all intensive purposes, .
All intents and purposes Steve. http://grammarist...urposes/
cantdrive85
1.8 / 5 (10) Jul 19, 2016
Physicist Richard Feynman coined the term "cargo cult science" for cases in which researchers believe they are doing science because their activities have the outward appearance of science but actually lack the "kind of utter honesty" that allows their results to be rigorously evaluated

Two words; Magnetic Reconnection.
Maggnus
3.7 / 5 (3) Jul 19, 2016
Two words; Magnetic Reconnection.
In the mind of this Acolyte, something which is observed cannot be (https://www.nasa....nection) but the imaginings of a lunatic viewing cave paintings should be accepted as Truth (TM). (http://skepdic.co...ov.html)
.

That such obvious bunkum is accepted by anyone speaks to a truism attributed to PT Barnum "there is a sucker born every minute".
LifeBasedLogic
Aug 08, 2016
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