Magnetic fields are an elusive but essential agent of galactic ecosystems. They are dynamically important and a binding actor of physical processes on scales associated with the filamentary structure of interstellar matter, star formation, cosmic rays acceleration and propagation, stellar feedback and the disk-halo connection. The magnetized interstellar medium (ISM) is also a hindrance to investigate cosmic signals: it muddles our view of sources of ultra-high energy cosmic rays (UHECR) and of extragalactic magnetic fields, it causes small-scale polarized synchrotron radiation that can mimic the signature of the 21cm line of neutral hydrogen in the dark ages of the universe, and produces dust polarization that hampers cosmic microwave background polarization measurements.

Much research has been done in the past decades trying to construct parametric models of Galactic magnetic fields (GMFs), their ordered and turbulent components, fitting observational data. However, these studies are very heterogeneous and incomplete in their use of theoretical knowledge and observational constraints. A broad range of science topics in astrophysics call for innovative steps in the modeling of GMFs, and a rapidly increasing wealth of observational data makes a renewed effort timely. We (the SOC members) are leading the IMAGINE project that aims to take the next step in Galactic magnetic field modeling. IMAGINE gathers a diverse and open group of researchers who are joined by an interest in GMFs. Our immediate goal is to coordinate and facilitate the development and improvement of models for the magnetic field in the Milky Way, contributing thereby to the wide variety of science questions that are influenced by GMFs.

The EWASS meeting offers us an opportunity to organize this special session to gather astrophysicists from a wide array of disciplines who share an interest in Galactic magnetic fields.

Programme

The programme will comprise three sessions. Each will be introduced by a review talk.

• Observational tracers of magnetic fields
• Galactic magnetic field modelling
• Cosmic ray propagation

Invited speakers

Review talks will be presented by

• Marijke Haverkorn (Radboud University Nijmegen, The Netherlands)
• Anvar Shukurov (Newcastle University, Newcastle, United Kingdom)
• Elena Orlando (Kavli Institute for Particle Astrophysics and Cosmology, Stanford, USA)

Scientific organisers

Francois Boulanger (ENS), Torsten Ensslin (MPIA), Marijke Haverkorn (Radboud University), Jörg Hörandel (Radboud University), Tess Jaffe (University of Maryland and NASA Goddard Space Flight Center), Jens Jasche (Stockholm University), Jörg Rachen (Radboud University), Anvar Shukurov (Newcastle University)

Contact

francois.boulanger @ ens.fr