Particles as tracers for the most massive explosions in the Milky Way
August 11, 2009
V838 Monocerotis briefly became one of the brightest stars in our galaxy. Its outburst discovered in January 2002, observations have indicated that V838 is defying the conventional understanding of erupting stars and stellar life cycles. Photo cred: NASA
Astronomers recently observed a mysterious flux of particles in the universe, and the hope was born that this may be the first observation of the remnants of "dark matter". But scientists from the University of Gothenburg, Sweden, have shown that there is another explanation of the flux.
Several independent studies recently discovered a mysterious flux of electrons and positrons in the universe. Several theories were presented that suggested that these particles arise from the decay of "dark matter" - the hypothetical material that is believed to influence the rotation of galaxies. Dark matter is one of the most challenging questions in astrophysics. An international research group with members from the University of Gothenburg has now published new results showing that the mysterious flux actually arises from exploding stars.
Supernova remnants
Julia Becker, from the Department of Physics at the University of Gothenburg, and her colleagues show in the article, which has been published in the scientific journal Physical Review Letters, that the mysterious particle flux is the remnant of a supernova, from a star that was 15 times more massive than the sun.
This star died and exploded in the Milky Way. When a star of this mass dies, most of its material is ejected and ploughs a pathway through a massive, stellar wind. This wind has been created earlier in the death process, when the star lost part of its original mass. The wind blows away from the star, and the final definitive explosion of the star then drives new material through the previously established wind.
A shock-wave in space
Electrons and positrons are accelerated during the process and create a shock-wave, similar to that formed when an aeroplane breaks the sound barrier. Julia Becker and her colleagues show that it is just such a shock-wave that has created the observed particle flux that has astounded scientists.
"This means, I'm afraid, that scientists will have to find another method of identifying dark matter", says Julia Becker.
More information: The article "Cosmic Ray Electrons and Positrons from Supernova Explosions of Massive Stars" was published in Physical Review Letters on 7 August. DOI: 10.1103/PhysRevLett.103.061101
-
First stars might have been powered by dark matter
Feb 12, 2008 |
not rated yet |
0
-
Chandra Spies Cosmic Fireworks
Jul 14, 2006 |
not rated yet |
0
-
Chandra discovers relativistic pinball machine
Nov 15, 2006 |
not rated yet |
0
-
Integral satellite disproves dark matter origin for mystery radiation
Jul 22, 2009 |
not rated yet |
0
-
Astrophysicists solve mystery in Milky Way galaxy
Jul 09, 2009 |
not rated yet |
0
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (4) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (2) |
0
-
Never ending outer space.....
21 hours ago
-
Neutron Star fragments?
23 hours ago
-
stationary or not?
Feb 11, 2012
-
Scale of the Universe
Feb 10, 2012
-
Titan's lack of impact craters
Feb 09, 2012
-
Real pictures of black hole eating a star?
Feb 08, 2012
- More from Physics Forums - General Astronomy
More news stories
Salvage workers begin pumping fuel from Italian shipwreck
Salvage workers Sunday began pumping fuel from the shipwrecked Italian cruise liner Costa Concordia, a day ahead of schedule, officials said.
6 hours ago |
5 / 5 (1) |
0
Latin America mining boom clashes with conservation
Latin America is experiencing a mining boom as prices rise fuelled by a hike in global demand, but the region is also being hit by a wave of violent protests, strikes and rallies by environmentalists.
14 hours ago |
5 / 5 (1) |
1
Political leaders play key role in how worried Americans are by climate change: study
More than extreme weather events and the work of scientists, it is national political leaders who influence how much Americans worry about the threat of climate change, new research finds.
Feb 06, 2012 |
5 / 5 (7) |
73
NASA budget will axe Mars deal with Europe: scientists
US President Barack Obama's budget proposal to be submitted next week for 2013 will cut NASA's budget by 20 percent and eliminate a major partnership with Europe on Mars exploration, scientists said Thursday.
Space & Earth / Space Exploration
Feb 10, 2012 |
5 / 5 (3) |
58
Humans may have helped the decline of African rainforests 3000 years ago
(PhysOrg.com) -- Large areas of rainforests in Central Africa mysteriously disappeared over three thousand years ago, to be replaced by savannas. The prevailing theory has been that the cause was a change ...
Feb 10, 2012 |
4.1 / 5 (14) |
21
|
Scientists discover molecular secrets of 2,000-year-old Chinese herbal remedy
For roughly two thousand years, Chinese herbalists have treated Malaria using a root extract, commonly known as Chang Shan, from a type of hydrangea that grows in Tibet and Nepal. More recent studies suggest that halofuginone, ...
New method to examine batteries -- MRI from the inside
There is an ever-increasing need for advanced batteries for portable electronics, such as phones, cameras, and music players, but also to power electric vehicles and to facilitate the distribution and storage of energy derived ...
Overeating may double risk of memory loss
New research suggests that consuming between 2,100 and 6,000 calories per day may double the risk of memory loss, or mild cognitive impairment (MCI), among people age 70 and older. The study was released today and will be ...
A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...
Lab study raises questions over nano-particle impact
Tests involving chickens have raised questions about the impact on health from engineered nano-particles, the ultra-fine grains commonly used in drugs and processed foods, scientists said on Sunday.
Google might launch Drive for cloud storage soon
(PhysOrg.com) -- Google's next big move, according to the Wall Street Journal, is a cloud storage service called Drive. Hardly first to the plate, Google is simply catching up to introducing its cloud reposi ...
Aug 11, 2009
Rank: 2.5 / 5 (8)
It is reassuring to see that ordinary matter explains yet another observation that had been attributed to imaginary "dark matter".
When the physics community starts to study seriously the properties of real matter shown here:
http://tinyurl.com/2otxps
They will probably be persuaded that "dark matter" is only an illusion.
That's my opinion,
Oliver K. Manuel
http://www.omatumr.com
Aug 11, 2009
Rank: 3.3 / 5 (7)
Oliver,
exactly what kind of 'professor' are you, did you get your degree in the mail?
Aug 11, 2009
Rank: 3 / 5 (4)
Aug 12, 2009
Rank: 4.8 / 5 (4)
Ok, I understand some people may have an issue with dark matter and dark energy but did you actually read some of the stuff that Oliver has posted on his website. He basically claims that our solar system is a supernova remnant and the current sun is the core of that old star that exploded. Never mind that supernova remnants turn into black holes or neutron stars about 10-20 kilometers wide.
Aug 12, 2009
Rank: 3.8 / 5 (5)
PhD in nuclear chemistry, postdoc fellowship in physics.
My academic research profile is below my signature.
With kind regards,
Oliver K. Manuel
http://myprofile....anuelo09
Aug 12, 2009
Rank: 2 / 5 (4)
Why not study seriously the properties of real matter shown here:
http://tinyurl.com/2otxps
Instead of those of imaginary "dark matter" ?
That's my question,
Oliver K. Manuel
http://www.omatumr.com
Aug 12, 2009
Rank: 5 / 5 (2)
Alright sorry for my rudeness but I just don't get it, are you saying there is a neutron star at the core of the sun?
You are talking about 'repulsive interactions' that partly powers the sun. Those repulsive interactions found in neutron stars are a result of fermi statistics that says two fermions cannot occupy the same point in space at the same time.
These forces come into play at extremely high densities. There is even some speculation that quark stars may exist, so condensed that even the hadrons are breaking down.
The problem with your theory is that these objects have extreme properties that would rip the sun apart in a matter of minutes or hours if there was one in the core. Some solar material would accumulate on the neutron star while the rest would be blasted out of our solar system, possibly in two jets along the polar spin axis.
Aug 12, 2009
Rank: 4.8 / 5 (4)
Oliver was an actual professor. You can look it up.
Try Oliver K. Manuel in Google or in the Missouri University site.
Neutron or iron. He switches on this. I can't get him to choose on or the other.
He won't deal with that either. Refuses to admit that the minimum size of a neutron star is 1.4 solar masses. Might be why he switches between an iron and a neutron core.
Other things Oliver is silent on.
Why he thinks that the standard models don't adequately explain the lack of helium and hydrogen in the inner solar system.
Where the evidence is that non-free neutrons can fission.
Why no one has detected this alleged behavior in neutrons.
And then there is the matter of why he refuses to discuss this except by reposting the papers that are the ones that are in doubt.
So far no one has got him to discuss this. On at least two separate forums.
Most likely he will now demand your credentials. That is standard when confronted. However in this case you set the precedent.
Ethelred
Aug 13, 2009
Rank: 1 / 5 (2)
is a shuddering shameful futile waste
The 21st century Dark-Realm Rush of science in search of Dark Energy-Matter is a shuddering and shameful waste of menpower and of many other resources on a commonsensical futile chase of a grand 100 year old virtual hallucination.
Again and again : dark energy-matter scientists keep chasing their selfmade gibbering tail.
And again and again : On The Origin Of Origins
http://www.the-sc...age#2753
http://www.physfo...ic=14988&st=525&#entry420991
Enough is enough!
Exercise critical thinking beyond Einstein-Hubble and beyond Darwin.
Dark Matter-Energy And Higgs Particle ???
Ponder energy-mass superposition and the Fractal Oneness of the universe.
Ponder the implication of the commonsensical universe scheme on the origin and nature of life.
Suggesting,
Dov Henis
(Comments from 22nd century)
http://profiles.y...MFQSDYEU