MIRAX: a Brazilian X-ray astronomy satellite mission Original Research Article

We describe the “Monitor e Imageador de Raios-X” (MIRAX), an X-ray astronomy satellite mission proposed by the high-energy astrophysics group at the National Institute for Space Research (INPE) in Brazil to the Brazilian Space Agency. MIRAX is an international collaboration that includes, besides INPE, the University of California San Diego, the University of Tübingen in Germany, the Massachusetts Institute of Technology and the Space Research Organization Netherlands. The payload of MIRAX will consist of two identical hard X-ray cameras (10–200 keV) and one soft X-ray camera (2–28 keV), both with angular resolution of ∼5–7′. The basic objective of MIRAX is to carry out continuous broadband imaging spectroscopy observations of a large source sample (∼9 months/yr) in the central Galactic plane region. This will allow the detection, localization, possible identification, and spectral/temporal study of the entire history of transient phenomena to be carried out in one single mission. MIRAX will have sensitivities of ∼ 5 mCrab/day in the 2–10 keV band (∼2 times better than the All Sky Monitor on Rossi X-ray Timing Explorer) and 2.6 mCrab/day in the 10–100 keV band (∼40 times better than the Earth Occultation technique of the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory). The MIRAX spacecraft will weigh about 200 kg and is expected to be launched in a low-altitude (∼600 km) circular equatorial orbit around 2007/2008.