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Interstellar heliospheric probe/heliospheric boundary explorer mission—a mission to the outermost boundaries of the solar system
Wimmer-Schweingruber, Robert F.; Valtonen, Eino; Wurz, Peter +4 more
The Sun, driving a supersonic solar wind, cuts out of the local interstellar medium a giant plasma bubble, the heliosphere. ESA, jointly with NASA, has had an important role in the development of our current understanding of the Suns immediate neighborhood. Ulysses is the only spacecraft exploring the third, out-of-ecliptic dimension, while SOHO h…
History of gamma-ray telescopes and astronomy
Pinkau, Klaus
Gamma-ray astronomy is devoted to study nuclear and elementary particle astrophysics and astronomical objects under extreme conditions of gravitational and electromagnetic forces, and temperature. Because signals from gamma rays below 1 TeV cannot be recorded on ground, observations from space are required. The photoelectric effect is dominant <…
AKARI: space infrared cooled telescope
Onaka, Takashi; Salama, Alberto
AKARI, formerly known as ASTRO-F, is the second Japanese space mission to perform infrared astronomical observations. AKARI was launched on 21 February 2006 (UT) and brought into a sun-synchronous polar orbit at an altitude of 700 km by a JAXA M-V rocket. AKARI has a telescope with a primary-mirror aperture size of 685 mm together with two focal-p…
Gamma-ray telescopes. 400 Years of astronomical telescopes
Gehrels, Neil; Cannizzo, John K.
The last half-century has seen dramatic developments in γ-ray telescopes, from their initial conception and development through to their blossoming into full maturity as a potent research tool in astronomy. Gamma-ray telescopes are leading research in diverse areas such as γ-ray bursts, blazars, Galactic transients, and the Galactic distribution o…
Fresnel zone plate telescopes for X-ray imaging II: numerical simulations with parallel and diverging beams
Rao, A. R.; Girish, V.; Nandi, Anuj +4 more
We present the results of simulations of shadows cast by a zone plate telescope which may have one to four pairs of zone plates. From the shadows we reconstruct the images under various circumstances. We discuss physical basis of the resolution of the telescope and demonstrate this by our simulations. We allow the source to be at a finite distance…
Prospects in space-based gamma-ray astronomy
Knödlseder, J.
Observations of the gamma-ray sky reveal the most powerful sources and the most violent events in the Universe. While at lower wavebands the observed emission is generally dominated by thermal processes, the gamma-ray sky provides us with a view on the non-thermal Universe. Here particles are accelerated to extreme relativistic energies by mechani…
The INTEGRAL HESS/MAGIC connection: A new class of cosmic high energy accelerators from keV to TeV
Ubertini, P.
The recent completion and operation of the High Energy Stereoscopic System [1], an array of ground based imaging Cherenkov telescopes, has provided a survey with unprecedented sensitivity of the inner part of the Galaxy and revealed a new population of very high energy gamma-rays sources emitting at E > 100 GeV. Most of them were reported to ha…
Annihilation of positrons in the Galaxy
Sunyaev, R.; Revnivtsev, M.; Sazonov, S. +1 more
Observations of electron-positron annihilation radiation from the Galactic Center region with the SPI instrument aboard INTEGRAL are summarized. The measured width of the 511 keV line and inferred fraction of positrons annihilating through positronium formation are consistent with the annihilation taking place in the warm ISM phase, although combi…
Cipher, A Polarimeter Telescope Concept for Hard X-Ray Astronomy
Stephen, J. B.; Caroli, E.; Curado da Silva, R. M. +1 more
The polarisation of astrophysical source emission in the energy range from a few tens of keV up to the MeV region is an almost unexplored field of high-energy astrophysics. Till date, polarimetry in astrophysics in the energy domain from hard X-rays up to soft γ-rays has not been pursued due to the difficulties involved in obtaining sufficient sen…
In-Orbit Vignetting Calibrations of XMM-Newton Telescopes
Finoguenov, A.; Gondoin, P.; Aschenbach, B. +4 more
We describe measurements of the mirror vignetting in the XMM-Newton Observatory made in-orbit, using observations of SNR G21.5-09 and SNR 3C58 with the EPIC imaging cameras. The instrument features that complicate these measurements are briefly described. We show the spatial and energy dependences of measured vignetting, outlining assumptions made…