Goals: While spectroscopy, photometry, and timing are techniques applied at all wavelengths, polarimetry has been so far used mainly in the radio and in the optical domains. This will change over the next decade with new X-ray and soft gamma-ray observatories being sensitive to a polarised signal. These include NASA's IXPE, ESA's Astrogam and XIPE, proposed for the M5 and M4 calls, and the Chinese mission eXTP. The community is at a time where polarimetry will become an important diagnostic tool for a wealth of sources from neutrons stars to AGN, opening an entirely new frontier on the multiwavelength studies of these sources.

Whilst X and gamma-ray polarimetry is yet to be fully established, optical and radio polarimetry has been pivotal in studying a variety of coherent and incoherent emission mechanisms, in several types of sources: from compact objects (neutron stars, white dwarfs, black holes), interacting binaries to AGN. It also plays an important role in investigating the properties of the extreme magnetic fields around neutron stars, and mapping the magnetic fields in diffuse emission environments, such as supernova remnants or pulsar-wind nebulae. Optical polarimetry has also been crucial in experiments in fundamental physics, such as testing for the first time the effects of vacuum birefringence in extreme magnetic fields, and verifying QED predictions. The optical polarimetry community is well established worldwide and extremely productive, with about 4000 refereed publications issued since 2000, covering a wide variety of subjects. This well-established community will form the backbone of the future multi-wavelength polarimetry community, which is already building on its expertise for planning the scientific exploitation of future missions. Our goal therefore is to bring together observers, instrumentalists and theorists to discuss how best the community can develop a multi-wavelength approach to polarimetry over the next decade.

Programme

• Session 1: Optical Polarimetry: present and future optical polarimetric science
• Session 2: High Energy Polarimetry, from the sun to AGNs
• Session 3: Polarimetric Synergies from Radio to Gamma-Rays

Invited speakers

• Stefano Bagnulo Armagh Observatory, UK
• Phillipe Laurent CEA/DRF/IRFU/DAp & APC, France
• Carole Mundell Bath University, UK

Scientific organisers
Prof. Roberto Mignani (Milan, Italy), Prof. Andy Shearer (NUIG, Ireland), Dr. Agnieszka Slowikowska (NCU, Torun, Poland) Prof. Silvia Zane (MSSL/UCL, UK)

Contact
andy.shearer @ nuigalway.ie