"The Universe is in fact observed not only through the different windows of the electromagnetic spectrum, but also through other cosmic messengers, i.e. through cosmic rays (CRs), neutrinos and gravitational waves (GWs). In general, gamma rays are the perfect companions for multi-messenger astronomy ... gamma-ray production is intimately related to the production of CRs. The latter are charged particles, mainly protons, whose energy spectrum covers a very wide range in energy and flux. Many questions regarding CRs are still open, especially looking at the most energetic ones above 1015 eV (1 PeV). The CR spectrum is approximately described by a power law: dN/dE ∼ E−Γ , where Γ is the spectral index. Γ is not constant, indicating a change in the properties of CRs, like their acceleration sites and chemical composition. For energies around ∼ 4 × 1015 eV, the flux starts to decrease more steeply: Γ changes from about 2.7 to about 3. This feature, marked with the term knee, is thought to indicate the maximum acceleration energy of Galactic sources ..."
Quote Details
Added by wikiquote-import-bot
Unverified quote
0 likes
Original Language: English
Available Languages (1)
Sources
A. De Angelis and M. Mallamaci: arXiv preprint (quote from p. 2)
https://en.wikiquote.org/wiki/Cosmic_ray
Revision History
No revisions have been submitted for this quote.
Categories
Cosmic ray
3 quotes on TrueQuotesView all quotes by Cosmic ray →
Related Quotes
"When I began life as a particle physicist fifty years ago, most of the major discoveries were made in Europe by peopl…"
"Why does the atmosphere have conductivity? Here and there among the air molecules there is an ion—a molecule of oxyge…"
"It is worth quoting Anthony Grafton’s summation of Scaliger’s assault on the prisca theologia presumptions of his con…"
"The first Graeco-Egyptian astrologists did not invent the discipline they claimed to teach the Hellenic world. They u…"
"In making his own calculation, however, Christopher Columbus preferred the values given by the medieval Persian geogr…"
"You climb a mountain situated close to the sea or a level plain, and then observe the setting of the sun and find out…"
"The gods living in the north at the Meru mountain (i.e., at the north pole) see the Sun, after it has risen, for half…"
"On any day calculate the longitude of the Sun and the Moon for sunrise or sunset without applying the longitude corre…"
"Having fixed a pole, on a level piece of ground, and having described a circle by a cord attached to the pole, one sh…"
"A hundred to you, ten thousand years, two Yugas, three Yugas, four we make."