Interstellar medium properties and high-energy processes
Dr Katia Ferrière (IRAP Toulouse)
I will review the observational properties of interstellar magnetic fields in the disk and halo of our Galaxy. These properties are inferred from a variety of observational methods, primarily based on polarization of starlight, polarization of dust infrared emission, Zeeman splitting, Faraday rotation, and synchrotron emission. I will discuss each of these methods in some detail and...
Dr Philipp Mertsch (Rudolf Peierls Centre for Theoretical Physics Oxford)
Gamma-ray data from Fermi-LAT reveal a bi-lobular structure extending up to 50 degrees above and below the galactic centre, which presumably originated in some form of energy release there less than a few million years ago. It has been argued that the gamma-rays arise from hadronic interactions of high energy cosmic rays which are advected out by a strong wind, or from inverse-Compton...
Dr Jérome Péty (IRAM & Observatoire de Paris)
Summarizing 20 years of efforts, we will quantify the CO luminosity and CO-H2 conversion factor applicable to diffuse but partially molecular ISM when H2 and CO are present but C+ is the dominant form of gas-phase carbon. To do this, we will discuss galactic lines of sight observed in HI, HCO+ and CO where CO emission is present but the intervening clouds are diffuse (locally Av ~ 1 mag) with...
Dr Patrick Hennebelle (LERMA Paris)
115. Non-thermal emission from molecular clouds in the Galactic centre: Illumination vs cosmic rays.
Dr Régis Terrier (APC Paris)
The molecular clouds at the Galactic centre (GC), Sgr B2 among others, emit strong Fe Kalpha photons as well as hard X-rays up to 100 keV. The origin of this emission has been the subject of a controversy. Irradiation by subrelativistic cosmic rays, electrons or protons, might account for the observed spectra, but it can also be the result of the illumination of the clouds by a past high...