Posted on 05/04/2009 1:58:51 PM PDT by LibWhacker
Data from several different space and ground based observatories imply the presence of a nearby object that is beaming cosmic rays our way. Scientists with the Fermi Space Telescope say an unknown pulsar may be close by, sending electrons and positrons towards Earth. Or another more exotic explanation is that the particles could come from the annihilation of dark matter. But whatever it is, the source is relatively close, surely in our galaxy. “If these particles were emitted far away, they’d have lost a lot of their energy by the time they reached us,” said Luca Baldini, a Fermi collaborator.
Comparing data from the Fermi space telescope with results from the PAMELA spacecraft and the High Energy Stereoscopic System (H.E.S.S.) ground-based telescope, the three observatories have found surprisingly more particles with energies greater than 100 billion electron volts (100 GeV) than expected based on previous experiments and traditional models.
Fermi is primarily a gammy ray detector, but its Large Area Telescope (LAT) is also tool for investigating the high-energy electrons in cosmic rays.
Cosmic rays are hyperfast electrons, positrons, and atomic nuclei moving at nearly the speed of light. Unlike gamma rays, which travel from their sources in straight lines, cosmic rays wend their way around the galaxy. They can ricochet off of galactic gas atoms or become whipped up and redirected by magnetic fields. These events randomize the particle paths and make it difficult to tell where they originated. But determining cosmic-ray sources is one of Fermi’s key goals.
Using the LAT, which is sensitive to electrons and their antimatter counterparts, positrons, the telescope looked at the energies of 4.5 million cosmic rays that struck the detector between Aug. 4, 2008, and Jan. 31, 2009 and found more of the high-energy variety than expected, those in with more than 1 billion electron volts (eV).
NASA spokesman Francis Reddy said the exact number of how many more is not currently available, due to the peculiarities of the data, but should be released soon.
But results from Fermi also refute other recent findings from a balloon-borne experiment. The Advanced Thin Ionization Calorimeter (ATIC) captured evidence for a dramatic spike in the number of cosmic rays at energies around 500 GeV from its high atmospheric location over Antarctica. But Fermi did not detect these energies.
“Fermi would have seen this sharp feature if it was really there, but it didn’t.” said Luca Latronico, a team member at the National Institute of Nuclear Physics (INFN) in Pisa, Italy. “With the LAT’s superior resolution and more than 100 times the number of electrons collected by balloon-borne experiments, we are seeing these cosmic rays with unprecedented accuracy.”
“Fermi’s next step is to look for changes in the cosmic-ray electron flux in different parts of the sky,” Latronico said. “If there is a nearby source, that search will help us unravel where to begin looking for it.”
Yes. Yes it is. Now we are sterile.
The Sun?
Just sayin’.
Ni Ni Na Na No No
Not sterile, just stupid. At least 52% of us have been affected.
The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
Simon Warwick-Smith
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Santa Claus versus the Martians!
Si...always a classic.
where’d ah put muh tin foil hat at?
Ping.
“If these particles were emitted far away, they’d have lost a lot of their energy by the time they reached us.”
Doesn’t that violate the law of conservation of energy? It’s like trying to explain red shift using “tired light.”
Actually...
Snip
There have been a number of studies over the past 15-20 years (1, 2, 3, 4, 5, 6 and 10), which suggest that sperm counts in man are on the decline. Since these changes are recent and appear to have occurred internationally, it has been presumed that they reflect adverse effects of environmental or lifestyle factors on the male rather than, for example, genetic changes in susceptibility. If the decrease in sperm counts were to continue at the rate that it is then in a few years we will witness widespread male infertility. To date it remains unknown why this is happening and the available preventative measures, which can be taken to avoid a continuation of this trend, are not common knowledge.
Told you.
Boltzmann's Constant is k = 8.6e-5 eV/kelvin, and when multiplied times the temperature it gives the exponential factor exp( - E/kT ) showing the probability of a state ( of motion ) being occupied at that temperature. So kT is a characteristic energy for the temperature. The surface of the sun is only a few thousand kelvin, near the ionization energy of Hydrogen.
Even at the center of the sun the temperature is "only" 10 million kelvin, giving a characteristic energy of a few thousand eV, or a few Kev.
They are talking about kinetic energies of 100 GeV. The Tevatron, as the name ( from Tera-eV ) implies, can accelerate protons to these energies but not electrons. The problem with electrons is that they are light, and when you sling them in a circle, even 2 miles around, at these energies they give it up as synchrontron radiation faster than you can put it in.
The mechanism for highly energetic cosmic rays was a big mystery through the 50's and 60's, into the 70's and 80's even, although that's when they started to get some ideas about them. Still mind boggling, though.
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