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NUCLEAR ENHANCEMENT OF THE PHOTON YIELD IN COSMIC RAY INTERACTIONS.
Michael Kachelriess1, Igor V Moskalenko2, Sergey S Ostapchenko2,3
1Institutt for fysikk, NTNU, NO-7491 Trondheim, Norway.
The Astrophysical Journal
|October 14, 2021
Summary
This study revises the nuclear enhancement factor in gamma-ray astronomy. It introduces a new calculation accounting for energy loss fractions, improving cosmic ray and interstellar medium interaction models for Fermi-LAT data analysis.
Area of Science:
- * Gamma-ray astronomy and astrophysics.
- * Cosmic ray physics and propagation.
- * High-energy particle interactions.
Background:
- * The nuclear enhancement factor is crucial for modeling diffuse gamma-ray emission from cosmic rays (CRs) interacting with the interstellar medium (ISM).
- * Accurate modeling of hadronic interactions is essential for studying CR acceleration, propagation, and for background estimation in new physics searches.
- * The Fermi Large Area Telescope provides high-quality data crucial for refining these models.
Purpose of the Study:
- * To address inaccuracies in current nuclear enhancement factor calculations.
- * To present a revised method for calculating the spectrally averaged energy loss fraction.
- * To provide an improved nuclear enhancement factor for gamma-ray astronomy.
Main Methods:
- * Re-evaluation of the spectrally averaged energy loss fraction in hadronic interactions.
- * Application of the QGSJET-II-04 and EPOS-LHC hadronic interaction models.
- * Calculation of a new nuclear enhancement factor based on revised energy loss fractions.
Main Results:
- * Identified deficiencies in commonly used nuclear enhancement factor calculations regarding energy loss fractions.
- * Developed a new calculation for the spectrally averaged energy loss fraction.
- * Derived a revised nuclear enhancement factor using advanced interaction models.
Conclusions:
- * The revised nuclear enhancement factor offers a more accurate representation of gamma-ray production from CR-ISM interactions.
- * This improved factor enhances the reliability of diffuse gamma-ray emission models.
- * The findings are critical for maximizing the scientific return from Fermi-LAT observations and future gamma-ray astronomy endeavors.
Keywords:
ISM: general Online-only material: color figurecosmic raysgamma rays: diffuse backgroundgamma rays: generalMore Related Videos
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