TY - JOUR
AU1 - Yoneda, Hiroki
AU2 - Aharonian, Felix
AU3 - Coppi, Paolo
AU4 - Siegert, Thomas
AU5 - Takahashi, Tadayuki
AB - Abstract: De-excitation gamma-ray lines, produced by nuclei colliding with protons, provide information about astrophysical environments where particles have kinetic energies of $10-100$ MeV per nucleon. In general, such environments can be categorized into two types: the interaction between non-thermal MeV cosmic rays and ambient gas, and the other is thermal plasma with a temperature above a few MeV. In this paper, we focus on the latter type and investigate the production of de-excitation gamma-ray lines in very hot thermal plasma, especially the dependence of the line profile on the plasma temperature. We have calculated the line profile of prompt gamma rays from $^{12}$C and $^{16}$O and found that when nuclei have a higher temperature than protons, gamma-ray line profiles can have a complex shape unique to each nucleus species. This is caused by anisotropic gamma-ray emission in the nucleus rest frame. We propose that the spectroscopy of nuclear de-excitation gamma-ray lines may enable to probe energy distribution in very hot astrophysical plasmas. This diagnostics can be a new and powerful technique to investigate the physical state of a two-temperature accretion flows onto a black hole, especially the energy distributions of the protons and nuclei, which are difficult to access for any other diagnostics.
TI - Line profile of nuclear de-excitation gamma-ray emission from very hot plasma
JF - Astrophysics
DO - 10.1093/mnras/stad2780
DA - 2023-09-11
UR - https://www.deepdyve.com/lp/arxiv-cornell-university/line-profile-of-nuclear-de-excitation-gamma-ray-emission-from-very-hot-xBSgpJWHkS
VL - 2023
IS - 2309
DP - DeepDyve
ER -