The group, funded through the Opus Grant UMO-2014/13/B/ST9/00945, is part of the department of Gamma-Ray Astrophysics (NZ12) at the Henryk Niewodniczański Institute of Nuclear Physics Polish Academy of Sciences in Krakow (IFJ PAN).

The P.I. of the Opus Project is Sabrina Casanova.

The project in a nutshell

The Earth is constantly bombarded by a flux of ultra relativistic particles, known as cosmic rays (CRs). Supernova remnants (SNRs) are the most promising candidates as sources of the Galactic CRs but a conclusive proof that SNRs are CR Pevatrons - sources capable of accelerating CRs up to PeV (=1015 eV) energies - is still missing. We still do not know, e.g., if hadron and lepton accelerators are of the same nature, what the proton and electron acceleration rates and spectra are, whether CR properties measured close to the Sun are representative of the CR background in the ISM, and what the characteristics of the CR transport through the Galactic Disk are.

Our project proposes a novel approach to studies of CR origin and propagation that, in contrast to current trends, is not focused on investigating directly the sources in which particle acceleration may take place but on the studies of the accelerated CRs that diffuse in the Galactic Disk and are being transported there in the magnetic fields of poorly known structure. We will use a phenomenological approach that utilizes Monte Carlo simulations of CR diffusion through the Galactic Disk to study in detail the spectrum of the radiation produced by CR particles over a large range in energy in the whole volume of the Galaxy. Within this phenomenological approach we will then compare these predictions with gamma-ray maps and spectra obtained from GeV to TeV energies with the current and future instruments of gamma-ray astronomy: Fermi, the High Energy Stereoscopic System (H.E.S.S.), the High Altitude Water Cherenkov (HAWC), and the upcoming Cherenkov Telescope Array (CTA). A particular emphasis will be placed on understanding the particle confinement and escape from the acceleration sites and on the processes occurring in molecular clouds (MCs), massive star forming regions, or in the Centre of our Galaxy.

We expect that such a systematic and non-standard approach will allow us to find new constraints on particle acceleration processesin the Galactic Disk and CR diffusion parameters and to determine which CR accelerators are able to provide enough power to sustain the Galactic CR luminosity. Our approach will also help to find an unambiguous proof of the SNR paradigm for Galactic Pevatrons and to investigate the relative importance of SNs of type Ia and II in contributing to the Galactic CR population.