Multi-wavelength Signatures of Cosmic Rays in the Milky Way

Abstract

Cosmic rays (CRs) propagate in the Milky Way and interact with the interstellar medium and magnetic fields. These interactions produce emissions that span the electromagnetic spectrum, and are an invaluable tool for understanding the intensities and spectra of CRs in distant regions, far beyond those probed by direct CR measurements. We present updates on the study of CR properties by combining multi-frequency observations of the interstellar emission and latest CR direct measurements with propagation models. Finally, we make predictions for e-ASTROGAM and AMEGO, proposed gamma-ray missions with a special focus at the MeV energy range.

ICRC Rapporteur: Space Based Gamma-ray Astronomy

“…Gamma-rays (Space) Jeremy S. Perkins [48] and [70] presented SEDs of Cyg X-1 and Eta Carinae respectively with an obvious gap in the MeV range, and [30] detailed the importance of looking at diffuse emission in the MeV. Figure 18: AMEGO is a proposed instrument for the MeV domain and this figure shows its preliminary sensitivity as presented by [71].…”

“…To dig deeper in the gamma-ray data, we must fully understand the gamma-ray emission of our own Galaxy. To this end, the GALPROP 2 team have been working on updates to the Fermi diffuse model using the most recent data available (electrons, 408 MHz, Planck, and Fermi-LAT [30]). They have also developed new 3D models for the interstellar medium [31] and the Galactic Gas [29].…”

“…Without this knowledge we will not be able to understand what is happening. A very obvious measurement will be of gamma-ray diffuse emission and [30] presented work on predictions for an all-sky observatory. Figure 19: Several collaborations are pushing instruments to search the MeV sky; a relatively unexplored region of the electromagnetic spectrum.…”