Signatures of a Two Million Year Old Supernova in the Spectra of Cosmic Ray Protons, Antiprotons, and Positrons.
نویسندگان
چکیده
The locally observed cosmic ray spectrum has several puzzling features, such as the excess of positrons and antiprotons above ~20 GeV and the discrepancy in the slopes of the spectra of cosmic ray protons and heavier nuclei in the TeV-PeV energy range. We show that these features are consistently explained by a nearby source which was active approximately two million years ago and has injected (2-3)×10^{50} erg in cosmic rays. The transient nature of the source and its overall energy budget point to the supernova origin of this local cosmic ray source. The age of the supernova suggests that the local cosmic ray injection was produced by the same supernova that has deposited ^{60}Fe isotopes in the deep ocean crust.
منابع مشابه
Detailed analysis of observed antiprotons in cosmic rays
In the present work, the origin of antiprotons observed in cosmic rays (above the atmosphere) is analyzed in details. We have considered the origin of the primaries, (which their interactions with the interstellar medium is one of the most important sources of antiprotons) is a supernova type II then used a diffusion model for their propagation. We have used the latest parameterization for anti...
متن کاملMeasurements of Cosmic-ray Proton and Helium Spectra from the Bess-polar Long-duration Balloon Flights over Antarctica
The BESS-Polar Collaboration measured the energy spectra of cosmic-ray protons and helium during two longduration balloon flights over Antarctica in 2004 December and 2007 December at substantially different levels of solar modulation. Proton and helium spectra probe the origin and propagation history of cosmic rays in the galaxy, and are essential to calculations of the expected spectra of cos...
متن کاملConstraining Galactic pγ Interactions with Cosmic Ray Electron and Positron Spectra
High energy protons produced by various sources of cosmic rays, e.g., supernova remnants, pulsar wind nebulae, active galactic nuclei and gamma-ray bursts, participate in pγ and pp interactions. Although pp interactions may be the dominant mechanism in our Galaxy, it is unclear how important pγ process is. We show that the upper bound on the fraction of total number of protons participating in ...
متن کاملPositive charge prevalence in cosmic rays: Room for dark matter in the positron spectrum
The unexpected energy spectrum of the positron/electron ratio is interpreted astrophysically, with a possible exception of the 100–300 GeV range. The data indicate that this ratio, after a decline between 0.5 and 8 GeV, rises steadily with a trend towards saturation at 200–400 GeV. These observations (except for the trend) appear to be in conflict with the diffusive shock acceleration (DSA) mec...
متن کاملCosmic Ray Antiprotons
Interstellar (IS) cosmic rays consist mainly of protons with a smaller admixture of heavier nuclei. Antiprotons (p’s) occur at an abundance of 10 of p’s. These energetic particles, kinetic energy K > 10 MeV, are Galactic in origin, not to be confused with the much denser solar wind plasma, with much lower K. The relative element abundances in cosmic rays (CRs) indicate that CR primaries are ion...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 115 18 شماره
صفحات -
تاریخ انتشار 2015