Group Chair: Victoria Kaspi, McGill University
High Energy Astrophysics (HEA), broadly meaning X-ray and gamma-ray astronomy, encompasses an extremely broad range of astrophysical science, with sources that include stars, black holes, neutron stars, white dwarfs, supernova remnants, the interstellar medium, galaxies, active galactic nuclei, galaxy clusters, gamma-ray bursters, all emitting via fundamental but extreme physical processes, including extremes of gravity, density, temperature and magnetic field. Many HEA phenomena are inaccessible at any other waveband.
In this report, we consider Canadian priorities for HEA, specifically focussing on astrophysics accessible primarily through X-ray and gamma-ray observations. Importantly, most observations in the X-ray regime and in most of gamme-ray regime can be done only from space; it is this space-based arena on which we focus here. We also briefly discuss some relevant particle-astrophysics (see §7).
This report is timely given that HEA is currently the fastest growing subfield of astronomy in Canada. Over one dozen astrophysics faculty hirings have been made in the past 10 years in HEA and related fields, including five Canada Research Chairs. Considering the cadre of postdoctoral, graduate and undergraduate student researchers these faculty employ, the HEA community in Canada now includes nearly 90 people. Thus the community is young, active and growing. While the last Long-Range Plan (LRP; 2000) for astrophysics in Canada made no mention of X-rays or gamma-rays, the Mid-term Review of the LRP (2005) specifically noted the growth of Canadian HEA, identifying its potential "to lead the way to a new area of exciting space astronomy in Canada."
We believe that significant Canadian involvement in one or more forefront HEA missions is essential for nurturing and retaining the vibrant expertise and talent of the Canadian HEA community. We therefore recommend that the CSA pursue involvement, both technical and scientific, in one or more of the following planned or envisioned international HEA missions (which are described in more detail in Appendix A):
Table 1: Document Terminology for X-ray Mission Attributes
* The effective area of XMM's PN instrument at 1 keV is ∼2600 cm2.