What is CHEAR?
What is High Energy Astrophysics?
Is CHEAR a pan-Canadian initiative?
How many sources of x-rays and gamma rays have been discovered beyond our own solar system?
What types of astronomical objects emit x-rays?
CHEAR is an acronym for Canadian High Energy Astrophysics Research and it comprises a group of researchers, primarily located at Canadian institutions, that seeks to champion high-energy astrophysics research in Canada. This group is responsible for promoting interactions amongst researchers in Canada and internationally, and to devise strategic plans with respect to Canadian involvement in future space missions that directly impact the science associated with high-energy astrophysics.
What is High Energy Astrophysics?
High Energy Astrophysics is a branch of astronomy associated with the study of celestial objects emitting high-energy photons. It centers primarily on X-ray and gamma-ray astronomy but also includes studies of astrophysical neutrinos, cosmic rays, and other electromagnetic wavebands such as the extreme ultraviolet.
Specific astronomical objects that are often studied in this field include neutron stars, pulsars, black holes, white dwarfs, supernova remnants, gamma rate bursts, and active galactic nuclei.
Is CHEAR a pan-Canadian initiative?
Yes. CHEAR is comprised of researchers from various universities and research institutes from across Canada. This includes:
St. Mary's University
Bishop's University
McGill University
Universite de Montreal
University of Toronto
University of Waterloo
University of Western Ontario
University of Manitoba
University of Alberta
University of Calgary
University of British Columbia
University of Victoria
National Research Council (HIA)
CHEAR is also supported by funds from the Canadian Space Agency in the form of a Disciplinary Working Group (DWG) grant.
How many sources of x-rays and gamma rays have been discovered beyond our own solar system?
As of the year 2000, approximately 250,000 known x-ray sources had been identified. Nearly one-half of these discoveries were made by the ROSAT x-ray satellite observatory alone. More recently, observations by XMM-Newton and the Chandra observatory should more than double this number. As for the gamma-ray sources, approximately 1000 have been discovered to date. This number will greatly increase in the near future thanks to observations that will be carried out by the GLAST All-Sky Survey.
What types of astronomical objects emit x-rays?
A very large number of objects in the universe emit such a large flux of x-rays that their x-ray brightness is easily measured. This includes our own Sun and many of the planets. Outside of our Solar System the brightest x-ray sources include x-ray binaries (interacting binary systems in which a neutron star or black hole is cannibalizing its companion star) and supernova remnants (the remains of an exploded star). However, almost every type of star (especially very massive stars), is known to emit x-rays. Outside of our own Milky Way galaxy, the brightest x-ray sources are rich clusters of galaxies and active galactic nuclei. Ordinary galaxies also emit x-rays but their x-ray luminosities are smaller.