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The great success of the Rossi X-Ray Timing Explorer (RXTE) has shown that X-ray timing is an excellent tool for the study of strong gravitational fields and the measurement of fundamental physical properties of black holes and neutron stars. Here, we describe a next-generation X-ray timing mission, the Relativistic Astrophysics Explorer (RAE), designed to fit within the envelope of a medium-sized mission. The instruments will be a narrow-field X-ray detector array with an area of 6 m2 equal to 10 times that of RXTE and a wide-field X-ray monitor. We describe the science made possible with this mission, the design of the instruments, and results on prototype large-area X-ray detectors. [Copyright &y& Elsevier]

The performance of the Time Projection Chamber (TPC) polarimeter for the Polarimeter for Relativistic Astrophysical X-ray Sources (PRAXyS) Small Explorer was evaluated using polarized and unpolarized X-ray sources. The PRAXyS mission will enable exploration of the universe through X-ray polarimetry in the 2–10 keV energy band. We carried out performance tests of the polarimeter at the Brookhaven National Laboratory, National Synchrotron Light Source (BNL-NSLS) and at NASA's Goddard Space Flight Center. The polarimeter was tested with linearly polarized, monochromatic X-rays at 11 different energies between 2.5 and 8.0 keV. At maximum sensitivity, the measured modulation factors at 2.7, 4.5 and 8.0 keV are 27%, 43% and 59%, respectively and the measured angle of polarization is consistent with the expected value at all energies. Measurements with a broadband, unpolarized X-ray source placed a limit of less than 1% on false polarization in the PRAXyS polarimeter. [ABSTRACT FROM AUTHOR]

Abstract: The VERITAS observatory is an imaging atmospheric Cherenkov telescope array located in southern Arizona and covers an energy range between 100GeV and 30TeV. The VERITAS collaboration pursues a rigorous observing program that targets a range of key science objectives in astrophysics and particle physics; the understanding of the origin of cosmic rays, the search for supersymmetric dark matter self-annihilation, illuminating the connection between black holes and relativistic jets and constraints to the cosmological diffuse infrared background. We provide a summary of results from the first two years of observations with the full 4-telecope array reported at RICAP09. [Copyright &y& Elsevier]

We have discovered large-scale moving X-ray and radio jets from the microquasar XTE J1550−564. Using X-ray and radio observations performed between 2000 and 2002, we showed that plasma ejected from XTE J1550−564 has been able to travel at relativistic velocities during many years, with evidence for gradual deceleration. The broadband spectrum of the jets is consistent with synchrotron emission from high energy particles accelerated in shocks. Full details can be found in Corbel et al. [Science 298 (2002a) 196], Karret et al. [ApJ 582 (2003) 933] and Tomsick et al. [ApJ (2003) 945]. [Copyright &y& Elsevier]

With 8 h of observations, VERITAS confirms the detection of two very high energy gamma-ray sources. The gamma-ray binary LS 5039 is detected with a statistical significance of 8.8 σ. The measured flux above 1 TeV is (2.5 ± 0.4) × 10 − 12 cm − 2 s − 1 near inferior conjunction and (7.8 ± 2.8) × 10 − 13 cm − 2 s − 1 near superior conjunction. The pulsar wind nebula HESS J1825-137 is detected with a statistical significance of 6.7 σ and a measured flux above 1 TeV of (3.9 ± 0.8) × 10 − 12 cm − 2 s − 1 . [ABSTRACT FROM AUTHOR]