Extremely Fast Acceleration of Cosmic Rays in a Supernova Remnant

Journal Article · Tue Oct 23 00:00:00 EDT 2007 · Nature 449:576-578,2007

DOI:https://doi.org/10.1038/nature06210· OSTI ID:918532

Uchiyama, Y; Aharonian, F A; Tanaka, T; Takahashi, T; Maeda, Y

Galactic cosmic rays (CRs) are widely believed to be accelerated by shock waves associated with the expansion of supernova ejecta into the interstellar medium. A key issue in this long-standing conjecture is a theoretical prediction that the interstellar magnetic field can be substantially amplified at the shock of a young supernova remnant (SNR) through magnetohydrodynamic waves generated by cosmic rays. Here we report a discovery of the brightening and decay of X-ray hot spots in the shell of theSNRRXJ1713.723946 on a one-year timescale. This rapid variability shows that the X-rays are produced by ultrarelativistic electrons through a synchrotron process and that electron acceleration does indeed take place in a strongly magnetized environment, indicating amplification of the magnetic field by a factor of more than 100. The X-ray variability also implies that we have witnessed the ongoing shock-acceleration of electrons in real time. Independently, broadband X-ray spectrometric measurements of RXJ1713.723946 indicate that electron acceleration proceeds in the most effective ('Bohm-diffusion') regime. Taken together, these two results provide a strong argument for acceleration of protons and nuclei to energies of 1 PeV (10{sup 15} eV) and beyond in young supernova remnants.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 918532
• Report Number(s): SLAC-PUB-12913
• Journal Information: Nature 449:576-578,2007, Journal Name: Nature 449:576-578,2007 Vol. 449
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCELERATION
AMPLIFICATION
Astrophysics
ASTRO
COSMIC RADIATION
DECAY
ELECTRONS
HOT SPOTS
HYDROMAGNETIC WAVES
INTERSTELLAR MAGNETIC FIELDS
MAGNETIC FIELDS
NUCLEI
PROTONS
SHOCK WAVES
SUPERNOVA REMNANTS
SYNCHROTRONS