Hubble finds telltale fireball after gamma ray burst

Aug 03, 2013
These images taken by NASA's Hubble Space Telescope reveal a new type of stellar explosion produced from the merger of two compact objects. Hubble spotted the outburst while looking at the aftermath of a short- duration gamma-ray burst, a mysterious flash of intense high-energy radiation that appears from random directions in space. Short-duration blasts last at most a few seconds. They sometimes, however, produce faint afterglows in visible and near-infrared light that continue for several hours or days and help astronomers pinpoint the exact location of the burst. In the image at left, the galaxy in the center produced the gamma-ray burst, designated GRB 130603B. The galaxy, cataloged as SDS J112848.22+170418.5, resides almost 4 billion light-years away. A probe of the galaxy with Hubble's Wide Field Camera 3 on June 13, 2013, revealed a glow in near-infrared light at the source of the gamma-ray burst, shown in the image at top, right. When Hubble observed the same location on July 3, the source had faded, shown in the image at below, right. The fading glow provided key evidence that it was the decaying fireball of a new type of stellar blast called a kilonova. Kilonovas are about 1,000 times brighter than a nova, which is caused by the eruption of a white dwarf. But they are 1/10th to 1/100th the brightness of a typical supernova, the self-detonation of a massive star. Credit: NASA, ESA, N. Tanvir (University of Leicester), A. Fruchter (STScI), and A. Levan (University of Warwick)

(Phys.org) —NASA's Hubble Space Telescope has provided the strongest evidence yet that short-duration gamma-ray bursts are triggered by the merger of two small, super-dense stellar objects, such as a pair of neutron stars or a neutron star and a black hole.

The definitive evidence came from Hubble observations in near-infrared light of the fading fireball produced in the aftermath of a short gamma-ray burst (GRB). The afterglow reveals for the first time a new kind of stellar blast called a kilonova, an explosion predicted to accompany a short-duration GRB.

A kilonova is about 1,000 times brighter than a nova, which is caused by the eruption of a white dwarf. Such a stellar blast, however, is only 1/10th to 1/100th the brightness of a typical supernova, the self-detonation of a massive star.

Gamma-ray bursts are mysterious flashes of intense high- that appear from in space. Short-duration blasts last at most a few seconds, but they sometimes generate faint afterglows in visible and near-infrared light that continue for several hours or days.

The afterglows have helped astronomers determine that GRBs lie in distant galaxies. The cause of short-duration GRBs, however, remains a mystery. The most popular theory is that astronomers are witnessing the energy released as two compact objects crash together. But, until now, astronomers have not gathered enough strong evidence to prove it, say researchers.

A team of researchers led by Nial Tanvir of the University of Leicester in the United Kingdom has used Hubble to study a recent short-duration burst in near-infrared light. The observations revealed the fading afterglow of a kilonova explosion, providing the "smoking gun" evidence for the merger hypothesis.

"This observation finally solves the mystery of the origin of short gamma-ray bursts," Tanvir said. "Many astronomers, including our group, have already provided a great deal of evidence that long-duration gamma-ray bursts (those lasting more than two seconds) are produced by the collapse of extremely . But we only had weak circumstantial evidence that short bursts were produced by the merger of compact objects. This result now appears to provide definitive proof supporting that scenario."

Astrophysicists have predicted that short-duration GRBs are created when a pair of super-dense in a binary system spiral together. This event happens as the system emits gravitational radiation, tiny ripples in the fabric of space-time. The energy dissipated by the waves causes the two objects to sweep closer together. In the final milliseconds, as the two objects merge, the death spiral kicks out highly radioactive material. This material heats up and expands, emitting a burst of light. This powerful kilonova blast emits as much visible and near-infrared light every second as the Sun does every few years. A kilonova lasts for about a week.

In a recent science paper Jennifer Barnes and Daniel Kasen of the University of California, Berkeley, and the Lawrence Berkeley National Laboratory presented new calculations predicting how kilonovas should look. They predicted that the same hot plasma producing the radiation will also act to block the visible light, causing the gusher of energy from the kilonova to flood out in near-infrared light over several days.

An unexpected opportunity to test this model came on June 3 when NASA's Swift Space Telescope picked up the extremely bright gamma-ray burst, cataloged as GRB 130603B, in a galaxy located almost 4 billion light-years away. Although the initial blast of gamma rays lasted just one-tenth of a second, it was roughly 100 billion times brighter than the subsequent kilonova flash.

The visible-light afterglow was detected at the William Herschel Telescope and its distance was determined with the Gran Telescopio Canarias, both located in the Canary Islands.

"We quickly realized this was a chance to test Barnes' and Kasen's new theory by using Hubble to hunt for a kilonova in near-," Tanvir said. The calculations suggested that the light would most likely be brightest in near-infrared wavelengths about 3 to 11 days after the initial blast. The researchers needed to act quickly before the light faded, so they requested Director's Discretionary Observing Time with Hubble's Wide Field Camera 3.

On June 12-13 Hubble searched the location of the initial burst, spotting a faint red object. An independent analysis of the data from another research team confirmed the detection. Subsequent Hubble observations three weeks later, on July 3, revealed that the source had faded away, therefore providing the key evidence it was the fireball from an explosive event.

"Previously, astronomers had been looking at the aftermath of short-period bursts largely in optical light, and were not really finding anything besides the light of the gamma-ray burst itself," explained Andrew Fruchter of the Space Telescope Science Institute in Baltimore, Md., a member of Tanvir's research team. "But this new theory predicts that when you compare near-infrared and optical images of a short gamma-ray burst about a week after the blast, the kilonova should pop out in the infrared, and that's exactly what we're seeing."

In addition to confirming the nature of short GRBs, the discovery has two important implications. First, the origin of many heavy chemical elements in the universe, including gold and platinum, has long been a puzzle. Kilonovas are predicted to form such elements in abundance, spraying them out into space where they could become part of future generations of stars and planets.

Second, the mergers of compact objects are also expected to emit intense gravitational waves, first predicted by Albert Einstein. Gravity waves have not yet been discovered, but new instruments under development may make the first detections within a few years. "Now it seems that by hunting for kilonovas, astronomers may be able to tie together the events giving rise to both phenomena," Tanvir said.

The team's results will appear online on Aug. 3 in the journal Nature.

Explore further: Transiting exoplanet with longest known year

More information: Nature paper (PDF)

Related Stories

Earth's gold came from colliding dead stars

Jul 17, 2013

We value gold for many reasons: its beauty, its usefulness as jewelry, and its rarity. Gold is rare on Earth in part because it's also rare in the universe. Unlike elements like carbon or iron, it cannot ...

Fermi and Swift see 'shockingly bright' burst

May 03, 2013

A record-setting blast of gamma rays from a dying star in a distant galaxy has wowed astronomers around the world. The eruption, which is classified as a gamma-ray burst, or GRB, and designated GRB 130427A, ...

Recommended for you

Transiting exoplanet with longest known year

16 hours ago

Astronomers have discovered a transiting exoplanet with the longest known year. Kepler-421b circles its star once every 704 days. In comparison, Mars orbits our Sun once every 780 days. Most of the 1,800-plus ...

Mysterious dance of dwarfs may force a cosmic rethink

22 hours ago

(Phys.org) —The discovery that many small galaxies throughout the universe do not 'swarm' around larger ones like bees do but 'dance' in orderly disc-shaped orbits is a challenge to our understanding of ...

Is our solar system weird?

Jul 18, 2014

Is our Solar System normal? Or is it weird? How does the Solar System fit within the strange star systems we've discovered in the Milky Way so far?

Upgraded telescope opens window to universe

Jul 18, 2014

An international team of astrophysicists including University of Adelaide researchers have announced the successful detection of pulsed gamma rays from the neutron star, the Vela pulsar, using their newly upgraded telescope ...

User comments : 24

Adjust slider to filter visible comments by rank

Display comments: newest first

Egleton
1 / 5 (9) Aug 03, 2013
A good bit of prediction. Well done.
However, here we go again making the assumption that all heavy elements are synthesised in stellar events.
If it can be shown that one non-stellar transmutation happens then surely that assumption must be discarded.
Muon catalysed fusion springs to mind.
Fleetfoot
5 / 5 (5) Aug 04, 2013
However, here we go again making the assumption that all heavy elements are synthesised in stellar events. If it can be shown that one non-stellar transmutation happens then surely that assumption must be discarded.


Only if you are being stupidly pedantic about "all", one atom in a universe isn't significant. If a scientist creates one atom by fusion in the lab, that doesn't invalidate our astronomical knowledge.

Muon catalysed fusion springs to mind.


The lifetime of a muon is around 2 microseconds so they don't exist other than as transient particles, not long enough to produce any significant quantity of material.
Reg Mundy
1.4 / 5 (11) Aug 04, 2013
Astrophysicists have predicted that short-duration GRBs are created when a pair of super-dense neutron stars in a binary system spiral together. This event happens as the system emits gravitational radiation, tiny ripples in the fabric of space-time. The energy dissipated by the waves causes the two objects to sweep closer together.

So "the system emits gravitational radiation, tiny ripples in the fabric of space-time" does it?
This is conjecture of the worst sort presented as fact. No such "radiation" has ever been detected despite numerous and expensive searches, and Einstein himself only suggested it would be as a theory. The constant presentation of the "reality" of the force of gravity by the scientific establishment prevents real scientists from actually thinking about the possibility that gravity does not really exist as a force at all.
encoded
1 / 5 (1) Aug 05, 2013
neutron repulsion strikes again hahahahaha
Fleetfoot
5 / 5 (3) Aug 05, 2013
The constant presentation of the "reality" of the force of gravity by the scientific establishment prevents real scientists from actually thinking about the possibility that gravity does not really exist as a force at all.


The fact that the "scientific establishment" has known since 1917 that "gravity does not really exist as a force" but is a geometrical curvature makes it obvious that you are a troll.
Urgelt
5 / 5 (4) Aug 05, 2013
At the risk of sounding like a troll... ugh... I will point out that the full nature of gravity isn't actually understood. We do not know, for example, if there is a particle associated with gravity (it doesn't seem likely at this juncture, but it's not ruled out). So to say "...has known since 1917 that 'gravity does not really exist as a force'..." is not particularly accurate.

Einstein conceptualized 'gravitational radiation' as ripples in the fabric of space-time, not as a force, but he was very open about admitting that the full story of gravity hadn't yet been told.

So rather than sitting firmly on one side of that fence or the other, perhaps we ought to admit that there's still a lot to learn about gravity, and think of ways to test its nature. Gravity wave detectors are one way to conduct tests, but even if gravity waves are detected, we'll still have unanswered questions - such as, is gravity quantized?
Fleetfoot
5 / 5 (4) Aug 06, 2013
So to say "...has known since 1917 that 'gravity does not really exist as a force'..." is not particularly accurate.


True, I was oversimplifying a bit. The point is that in GR forces only cause objects to move away from a geodesic path while "gravity" is an effect of the intrinsic curvature of the Reimann geometry which defines those geodesics.

Einstein conceptualized 'gravitational radiation' as ripples in the fabric of space-time, not as a force..


That is as inaccurate as my statement ;-) Minkowski conceptualised SR as Reimann geometry and Einstein then used that to formulate GR. GR itself predicts the existence of gravitational waves regardless of any conceptualisation.

even if gravity waves are detected, we'll still have unanswered questions - such as, is gravity quantized?


Of course, but where we are at the moment is GR and it's pointless to speculate on what any future replacement for GR might tell us until we have some workable versions.
GSwift7
2.3 / 5 (3) Aug 07, 2013
Now it seems that by hunting for kilonovas, astronomers may be able to tie together the events giving rise to both phenomena," Tanvir said


That's a really profound fundamental advance, if they are able to follow through with that. If that works out, it will fill in a bunch of other missing pieces as well.

As for whether gravity is a force or not:

I saw some comments regarding the opinion of mainstream science. That depends on whether you are a cosmologist or a quantum physicist. GR treats gravity as a consequence of variations of space and time, and not a true force. QT treats gravity as a true force with force-carrying quasi-particles.

As for gravity waves, in my limited understanding, I'm not very confident they exist. It seems to me that they would cause a information paradox in relation to the event horizon of a black hole. I've discussed that with a few others here before and they don't agree, but oh well. Their speculation is just as good as mine. :)
Fleetfoot
5 / 5 (1) Aug 07, 2013
GR treats gravity as a consequence of variations of space and time, and not a true force. QT treats gravity as a true force with force-carrying quasi-particles.


QM can define the properties of the graviton but that has to act in a background geometry. You can't apply the Minkowski Metric over the whole universe so there's an open question there that needs to be addressed to construct a full QM description.

As for gravity waves, in my limited understanding, I'm not very confident they exist. It seems to me that they would cause a information paradox in relation to the event horizon of a black hole. I've discussed that with a few others here before and they don't agree, but oh well.


I don't see why you think that.

Their speculation is just as good as mine. :)


It's hardly speculation, they are an inevitable consequence of the equations of GR which are extremely well tested, and of course there is Hulse and Taylor's indirect observational evidence.
GSwift7
2.3 / 5 (3) Aug 08, 2013
I don't see why you think that.


Gravity is the one thing that propagates freely out of the event horizon. If gravity waves exist, then it should be possible to get 'information' out of a black hole by way of gravity waves. It would be something 'detectable' from inside the event horizon, which would be a paradox.

IIRC, you (or was it Qstar?) tried to view the event horizon as the source, but that's a fallacy, IMO. So, your speculation on that is no better or worse than mine, until such waves are actually detected.

However, the simple fact that the gravity of a black hole is able to escape the event horizon seems to speak volumes. If gravity has a propagation speed, then that shouldn't be possible. If it doesn't have a propagation speed, then gravity waves won't happen. That's all based on a huge stack of assumptions, no matter which view you favor. There's not really any reason to believe either one more than the other.
Q-Star
3.3 / 5 (14) Aug 08, 2013
IIRC, you (or was it Qstar?) tried to view the event horizon as the source, but that's a fallacy, IMO. So, your speculation on that is no better or worse than mine, until such waves are actually detected.


No I never tried to view the horizon as the source.

The causal mechanism is the mass contained within the volume of the event horizon. Gravitational waves are NOT "emitted". (Not like a beam of photons being emitted by a light source.) They are fluctuations in the spacetime curvature near an object or between two objects. No information is being transferred, Nothing is being transferred, the spacetime is fluctuating. They are perturbations of the spacetime, not something being "emitted" by that object.

Forget trying to view this by thinking of the way electromagnetism works, the phenomena are completely different and can't be set on equal terms when describing them. No information is passing out of the even horizon, nothing is passing out of the event horizon.
GSwift7
1 / 5 (1) Aug 09, 2013
No information is being transferred, Nothing is being transferred, the spacetime is fluctuating. They are perturbations of the spacetime, not something being "emitted" by that object


yes, that's how it should be

If a massive object falls into a black hole, (like another black hole, for example) then there should be gravity waves at the exact instant they merge (if the gravity wave theory is correct). Would those waves be detectable outside the event horizon?
Q-Star
2.8 / 5 (11) Aug 09, 2013
If a massive object falls into a black hole, (like another black hole, for example) then there should be gravity waves at the exact instant they merge (if the gravity wave theory is correct). Would those waves be detectable outside the event horizon?


Only those which were generated PRIOR to the in-falling object passing the event horizon. Once it crosses the event horizon, whatever it is doing after it's in there is lost to us.
Q-Star
3.2 / 5 (11) Aug 09, 2013
@ Zephyr,,

I don't have a lot of time to entertain ya, but ya are conflating particles and fields. If gravitational waves are emitted, then ya are positing the graviton. If that is so, being a particle it can not exceed "c".

If gravitational waves are a field, then then a particle is NOT required, and the field is only fluctuations of spacetime, and nothing is being emitted, only spacetime is jiggling around.

Both views are tenable with current physics.

Either way, NOTHING is moving from inside the event horizon to the outside universe.
Q-Star
3.5 / 5 (13) Aug 09, 2013
You're essentially spreading your own crackpot theories about it here. I would have no problem with it, but you should always separate the mainstream physics from your private ideas for not to confuse the readers. .


Zeph, ya've made me day. (Oh, what I would give to see your expression as ya typed that.)
GSwift7
2 / 5 (4) Aug 09, 2013
That answer to that question actually depends on whether gravity has a limited speed or if it is an instantaneous effect. Either way presents difficulties in relation to relativistic situations.

I had trouble understanding the difference at first, but I found an analogy that helps.

Imagine the strength of gravity as the level of water in a glass. At neutral state, the glass is half full (or empty). Gravity waves (if they exist) are waves in the water. So, if you drop an object into the glass there's two ways the water can act. If you are able to lower the object into the glass without making waves, then the surface level of the water will uniformly increase accross the entire area of the glass simultaneously. This is a universe without gravity waves, where the speed of gravity is instant. If the water is able to have waves, then as you lower the object into the glass, the increase in water level will propogate outwards from your object as a wave.

cont.
GSwift7
3.7 / 5 (3) Aug 09, 2013
So, if you drop an object in suddenly, you'll get repeating waves, not just a single increase of gravity, but a fluctuation up and down. This would be the gravity waves they are looking for in the merger of two very massive objects.

So, here's the quandry: If there are waves, then gravity must have a limited speed of propogation. The most popular interpretation says this is the case. However, a black hole is a special case, and it's not clear how it affects this. So, that leaves a couple questions we need to answer. 1)Are there gravity waves? 2)If there are, then can we detect them from inside an event horizon?

Nothing with a limited speed should be detectable outside an event horizon, but there shouldn't be anything with unlimited speed. So, I don't think we should be able to detect a gravity wave from a black hole. It'll make them, but they won't escape. IMO.

Those are very important test questions, with profound impact on the nature of Everything.
GSwift7
2.3 / 5 (3) Aug 09, 2013
Only those which were generated PRIOR to the in-falling object passing the event horizon. Once it crosses the event horizon, whatever it is doing after it's in there is lost to us


Yes, I agree, but there isn't a clear concensus on that.
GSwift7
4 / 5 (4) Aug 09, 2013
The waves existing in extradimensions


Yeah, I just watched The Avengers again last night on Netflix. I think that extradimensional stuff is cool. You should go ahead and make a portal and bring Thor to Earth. Did you know his hammer is made from neutron star material? I wonder how he can carry it in an airplane without overloading the plane, since the Hulk couldn't even lift it? That must have something to do with extra dimensions too. Or it might float on the aether. Ooooo, Thor's powers include giant space lightning bolts, so he probably made the grand canyon for Candrive too. I didn't realize how much PC and AWT both look so much like the Marvell Universe until just now. Is that where you guys get this stuff? Come on, really, tell me.
cantdrive85
1 / 5 (10) Aug 09, 2013
"It is the Thunderbolt that steers the universe." Heraclitus, ca. 500BC

Comparative mythology is foundational for Electric Universe theory, not PC. PC also doesn't adhere to the EU's POV in re to the dramatic geologic processes suggested by EU, i.e. EDM. Although Peratt did produce a paper on EDM about Io, his POV on the actions is secondary to the tidal model. EU is multi-interdisciplinary, PC less so. But I'm not surprised by the confusion being I can tell your entire knowledge of both theories is superficial at best. Almost every opinion directed toward both theories is based upon utter ignorance of the processes proposed.

Mjölnir, described as lightning with similar effects as the Varja, was capable of leveling mountains (or creating canyons one would suppose) and was created from a dying star(the first sun, similar to myths in Egypt, Sumeria, Greece, Aztecs, Chinese, Hindu, and many others). Comparative mythology may have more to tells us than you're willing to accept.
aroc91
5 / 5 (5) Aug 09, 2013
Ancient fables as evidence of your pet theory? That's just sad.
cantdrive85
1 / 5 (10) Aug 10, 2013
Ancient fables as evidence of your pet theory? That's just sad.

Yep, based on peer reviewed material and archetypal comparative mythology, not comic book legends.
http://www.plasma...rth.html
http://mythopedia...lio.html

And it's only one of the multi-disciplinary aspects that is mutually supportive of this complete cosmology.
barakn
5 / 5 (2) Aug 10, 2013
Almost every opinion directed toward both theories is based upon utter ignorance of the processes proposed. -cantdrivel85
And that's from its supporters.
GSwift7
3.7 / 5 (3) Aug 12, 2013
Almost every postulate of both theories is based upon utter ignorance of the processes proposed


I saw your mistake and fixed it for you.

Your welcome.