Λεπτομέρειες βιβλιογραφικής εγγραφής
| Τίτλος: |
The spectral shape of shock-accelerated particles. |
| Συγγραφείς: |
Xu, Y. D.1,2 (AUTHOR), Li, G.1 (AUTHOR) gli@must.edu.mo |
| Πηγή: |
Astronomy & Astrophysics / Astronomie et Astrophysique. 2026, Vol. 713, p1-6. 6p. |
| Θεματικοί όροι: |
*Exponential decay law, *Scale invariance (Statistical physics), *Gamma rays, *Mechanical shock, *Transport equation |
| People: |
Parker, William Anthony, 1982- |
| Περίληψη: |
Context. Particle acceleration at collisionless shocks, governed by Parker's transport equation, is frequently characterized by a power-law energy spectrum with an exponential cutoff, typically taking the form ∼E−γexp(−E/E0). In high-energy astrophysics, the exponential decay is often generalized to ∼exp(−(E/E0)β) to model both Galactic cosmic rays and gamma-ray spectra. Aims. We aim to propose a new spectral fitting formalism governed entirely by physically interpretable parameters, providing a comprehensive framework for interpreting observed energy spectra across space plasmas and high-energy astrophysics. Methods. Operating within the test-particle regime of diffusive shock acceleration, we derive a novel approximant for the energy spectrum of accelerated particles in the context of nonrelativistic piecewise shocks. Results. Our formulation reveals a previously uncharacterized transitional phase in the energy spectrum, situated between the canonical low-energy power-law distribution and the high-energy exponential decay asymptote. Furthermore, this approach demonstrates the emergence of robust spectral self-similarity across different ion species and temporal stages of the acceleration process. [ABSTRACT FROM AUTHOR] |
| Βάση Δεδομένων: |
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