Related papers: The Challenge to Large Optical Telescopes from X-r…
One of the few remaining astronomical bands (factor of $\sim$10 in energy range) still without an all-sky imaging survey is the hard x-ray band (10-600 keV). This is in spite of sensitive imaging all-sky surveys already conducted at soft…
In this paper we investigate the properties of low X-ray-to-optical flux ratio sources detected in a wide area (2.5deg^2) shallow (f(0.5-8keV)~10e-14cgs) XMM-Newton survey. We find a total of 26 sources (5% of the total X-ray selected…
Since the launch of Chandra and XMM-Newton, high-resolution X-ray spectra of cosmic sources of all kinds have become available. These spectra have resulted in major scientific breakthroughs. However, due to the techniques used, in general…
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…
Hard X-ray, large area surveys are a fundamental complement of ultra-deep, pencil beam surveys in obtaining a more complete coverage of the L-z plane, allowing to find luminous QSO in wide z ranges. Furthermore, results from these surveys…
Recent weak lensing observations have pushed the use of 4 meter-class telescopes to the limits of their capabilities with exposure times exceeding several hours. The leading idea is that the surface density of faint galaxies up to very…
The Chandra and XMM-Newton X-ray telescopes have led to numerous advances in the study and understanding of astrophysical X-ray sources. Particularly important has been the much increased spectral resolution of modern X-ray instrumentation.…
Hard X-ray observations are the most efficient way to discriminate accretion-powered sources from star-light. Furthermore, hard X-rays are less affected than other bands by obscuration. For these reasons the advent of imaging instruments…
Study of energetic cosmic explosions as a part of time domain astronomy is one of the key areas that could be pursued with upcoming Giant segmented optical-IR telescopes with a very large photon collecting area applying cutting edge…
(Abridged) This paper presents the data recently released for the XMM-Newton/WFI survey carried out as part of the ESO Imaging Survey (EIS) project. The aim of this survey is to provide optical imaging follow-up data in BVRI for…
We present extensive optical, radio and infrared follow-up observations of a sample of 35 hard X-ray (2-10 keV) selected sources discovered serendipitously in the PV XMM-Newton observation of the radio-loud quasar PKS 0312-77 field, for…
We report on a medium deep XMM-Newton survey of the Marano Field and optical follow-up observations. The mosaicked XMM-Newton pointings in this optical quasar survey field cover 0.6 square degree with a total of 120 ksec good observation…
The Wide Field X-Ray Telescope (WFXT) is a medium-class mission designed to be 2-orders-of-magnitude more sensitive than any previous or planned X-ray mission for large area surveys and to match in sensitivity the next generation of…
X-ray polarimetry promises to give qualitatively new information about high-energy sources. Examples of interesting source classes are binary black hole systems, rotation and accretion powered neutron stars, Microquasars, Active Galactic…
Recent X-ray observations have had a major impact on topics ranging from protostars to cosmology. They have also drawn attention to important and general physical processes that currently limit our understanding of thermal and nonthermal…
The ~1 Ms Chandra Deep Field North observation is used to study the extended X-ray sources in the region surrounding the Hubble Deep Field North (HDF-N), yielding the most sensitive probe of extended X-ray emission at cosmological distances…
We describe a possible new class of X-ray sources that have robust detections in ultra-deep Chandra data, yet have no detections at all in our deep multi-band GOODS Hubble Space Telescope (HST) ACS images, which represent the highest…
We present followup observations of five hard X-ray sources from the ASCA 5-10 keV SHEEP survey, which has a limiting flux of $\sim 10^{-13}$ erg cm$^{-2}$ s$^{-1}$. Chandra data have been obtained to improve the X-ray positions from a few…
A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if…
The history of X-ray astronomy has shown that any advancement in our knowledge of the X-ray sky is strictly related to an increase in instrument sensitivity. At energies above 60 keV, there are interesting prospects for greatly improving…