scholarly journals Diffractive X-Ray Telescopes

2010 ◽  
Vol 2010 ◽  
pp. 1-17 ◽  
Author(s):  
Gerald K. Skinner

Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of microarcseconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the supermassive black holes in the center of active galaxies What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

Author(s):  
P. Laurent ◽  
F. Acero ◽  
V. Beckmann ◽  
S. Brandt ◽  
F. Cangemi ◽  
...  

AbstractBased upon dual focusing techniques, the Polarimetric High-Energy Modular Telescope Observatory (PHEMTO) is designed to have performance several orders of magnitude better than the present hard X-ray instruments, in the 1–600 keV energy range. This, together with its angular resolution of around one arcsecond, and its sensitive polarimetry measurement capability, will give PHEMTO the improvements in scientific performance needed for a mission in the 2050 era in order to study AGN, galactic black holes, neutrons stars, and supernovae. In addition, its high performance will enable the study of the non-thermal processes in galaxy clusters with an unprecedented accuracy.


2003 ◽  
Vol 214 ◽  
pp. 243-245
Author(s):  
Stefanie Komossa ◽  
Weimin Yuan ◽  
Da Wei Xu

In the last few years, several giant-amplitude, non-recurrent X-ray flares have been observed from optically non-active galaxies. The observations were interpreted in terms of the long-predicted tidal disruption flares of stars captured by supermassive black holes. In this contribution, we review the observations and interpretation of the X-ray flares and add some new thoughts. Future X-ray observations of the flare events are expected to open up a new window to detect and investigate SMBHs and their immediate environment in galaxies. Here, we concentrate on the possibility to detect new X-ray flares in deep fields with the planned European X-ray mission XEUS.


2002 ◽  
Vol 17 (12n13) ◽  
pp. 1799-1808 ◽  
Author(s):  
MARCO TAVANI

Gamma-ray astrophysics in the energy range between 30 MeV and 30 GeV is in desperate need of arcminute angular resolution and source monitoring capability. The AGILE Mission planned to be operational in 2004-2006 will be the only space mission entirely dedicated to gamma-ray astrophysics above 30 MeV. The main characteristics of AGILE are the simultaneous X-ray and gamma-ray imaging capability (reaching arcminute resolution) and excellent gamma-ray timing (10-100 microseconds). AGILE scientific program will emphasize a quick response to gamma-ray transients and multiwavelength studies of gamma-ray sources.


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