Scientific Rationale
The year 2012 is significant for neutron-star and pulsar science, marking the 80th anniversary of both Chadwick's discovery of the neutron and Landau's idea of stars formed of matter at nuclear density. Just two years later, in 1934, Baade and Zwicky suggested that formation of neutron stars resulted in supernova explosions. With the discovery of pulsars by Hewish and Bell 33 years later, these ideas were finally given a firm observational basis. Since that time, the topics of neutron-star and pulsar science have grown enormously, diversifying into many areas of astronomy and astrophysics. From the original radio pulsars with periods of order one second, we now have X-ray and gamma-ray pulsars, magnetars, millisecond pulsars and long-period transient pulsars. With their high density, rapid rotation, very strong magnetic fields, ultra-relativistic plasmas and high-energy emission, pulsars are a wonderful laboratory for study of high-energy astrophysics and particle physics. But they are more than that. As the products of supernova explosions, they give us a window into the evolution of massive stars, especially into the final moments of this evolution when the core of the star collapses to form a neutron star. Their ultra-stable pulse periodicities and common occurrence as members of binary systems makes them outstanding probes of gravitational theories. They offer the exciting prospects of the direct detection of gravitational waves and the establishment of a long-term standard of time more stable than the best atomic clocks. Furthermore, their compact size, pulsed emission and high polarisation makes them wonderful probes of the interstellar medium and of the circumstellar medium in close binary systems.
The topics chosen for this symposium reflect the great diversity of neutron-star and pulsar research and the many manifestations of neutron stars which have become apparent since these initial discoveries and ideas 80 years ago. Current radio, X-ray and gamma- ray observations are uncovering new types of object which blur the distinctions between magnetars, high-magnetic-field radio pulsars and X-ray-detected neutron stars. The planned program also reflects the huge advances made in the last year or so with new discoveries from radio telescopes and especially with the Fermi Gamma-ray Space Telescope as well as new algorithmic developments in pulsar timing and other areas that have revolutionized pulsar astrophysics. It also looks forward to developments in the next few years with the completion of large new instruments such as LOFAR, the European low-frequency radio telescope array, and the 500-m Arecibo-like FAST radio telescope, currently under construction in Guizhou province of China.
With all of these new developments, pulsar astrophysics has become a very exciting field. An IAU Symposium in 2012 is an ideal opportunity to bring these results and ideas together and to reflect on future developments. The Symposium Proceedings will form an excellent summary of the current state of pulsar astrophysics which will be valuable to established pulsar researchers, to young scientists beginning a research career in related areas and to scientists generally who need a current overview of the topic.
Key Topics
- Pulsar genesis and neutron-star structure
- X-ray and gamma-ray emission from pulsars, especially recent results from Fermi
- Pulsar diversity – relationship of magnetars, INS, CCOs, RRATs to radio pulsars
- Pulsar astronomy with large radio telescopes – looking forward to FAST and the SKA
- Toward a census of Galactic neutron stars – Galactic distribution and evolution
- Magnetospheric structure – pair creation and currents, magnetic decay, pulsar braking
- Non-thermal emission physics – giant radio pulses, mode changing, high-energy emission
- Binary pulsars – eclipsing systems, post-Newtonian physics, stellar masses
- Pulsar Timing Arrays – detection of gravitational waves and a pulsar time standard
- Pulsars as probes of the interstellar medium