Related papers: Active X-ray Optics for Generation-X, the Next Hig…
The latest all-sky survey in hard X-ray band was performed by the HEAO-1 satellite (13-80 keV) with an angular resolution of 24x48 arcmin. A diffuse hard X-Ray background (HXB) was detected between 3 and 50 keV. The main scientific goal of…
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…
In the ROSAT era of the mid-1990's, the problems facing deep X-ray surveys could be largely solved with 10 m class telescopes. In the first decade of this new millennium, with X-ray telescopes such as the Chandra X-ray Observatory and…
Grazing-incidence X-ray optics have revolutionized X-ray astrophysics. The ability to concentrate flux to a tiny detection region provides a dramatic reduction in background and a consequent very large improvement in sensitivity. The X-ray…
The energy range of hard X-rays is a key waveband to the study of high energy processes in celestial objects, but still remains poorly explored. In contrast to direct imaging methods used in the low energy X-ray and high energy gamma-ray…
Star-forming regions have been the targets of X-ray observations since the dawn of satellite X-ray astronomy. The increase in sensitivity and/or spatial resolution offered by XMM-Newton and Chandra allows a dramatic improvement, both…
X-ray astronomy needs to set bold, science driven goals for the next decade. Only with defined science goals can we know what to work on, and a funding agency appreciate the need for significant technology developments. To be a forefront…
Much of the baryonic matter in the Universe, including the most active and luminous sources, are best studied in the X-ray band. Key advances in X-ray optics and detectors have paved the way for the Advanced X-ray Imaging Satellite (AXIS),…
We briefly review X-ray studies of ionized AGN outflows and high-redshift AGN. We discuss recent progress with Chandra and XMM-Newton as well as prospects and requirements for future X-ray missions.
This paper discusses the broad science case for obtaining milliarcsecond to microarcsecond astronomical imaging resolution in the soft to medium-energy X-ray band (~0.5 to ~8 keV). Astronomy across much of the electromagnetic spectrum has…
Current X-ray observations and simulations show that gravitational lensing can be used to infer the structure near the event horizons of black holes, constrain the dynamics and evolution of black-hole accretion and outflows, test general…
Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event…
SIMBOL-X is a hard X-ray mission, operating in the 0.5-70 keV range, which is proposed by a consortium of European laboratories for a launch around 2010. Relying on two spacecraft in a formation flying configuration, SIMBOL-X uses a 30 m…
The R~300-1000 grating spectra from XMM-Newton and Chandra are a radical advance, allowing spectroscopic physics techniques to be applied to X-ray astronomy, revolutionizing a wide range of research. Ten years on these spectra will be…
AXTAR is an X-ray observatory mission concept, currently under study in the U.S., that combines very large collecting area, broadband spectral coverage, high time resolution, highly flexible scheduling, and an ability to respond promptly to…
X-ray diffraction gratings play an essential role in high-resolution spectroscopy of astrophysical phenomena. We present some scientific highlights from the X-ray grating spectrometers (XGS) on board of the Chandra and XMM/Newton missions,…
AXIS is a probe-class concept under study for submission to the 2020 Decadal Survey. AXIS will extend and enhance the science of high angular resolution X-ray imaging and spectroscopy in the next decade with $\sim 0.4''$ resolution over a…
Astronomical imaging with micro-arcsecond ($\mu$as) angular resolution could enable breakthrough scientific discoveries. Previously-proposed $\mu$as X-ray imager designs have been interferometers with limited effective collecting area. Here…
The discovery of X-ray emission from cosmic sources in the 1960s has opened a new powerful observing window on the Universe. In fact, the exploration of the X-ray sky during the 70s-90s has established X-ray astronomy as a fundamental field…
The X-ray observatories XMM-Newton and Chandra provided a wealth of exciting new results. Chandra delivered X-ray images of outstanding detail, reaching subarcsecond spatial resolution for the first time in X-ray astronomy. XMM-Newton…