Related papers: X-ray variability with WFXT: AGNs, transients and …
We present the Microchannel X-ray Telescope, a new light and compact focussing telescope that will be flying on the Sino-French SVOM mission dedicated to Gamma-Ray Burst science. The MXT design is based on the coupling of square pore…
High-redshift blazars are among the most powerful objects in the Universe. The spectral and temporal properties of thirty-three distant blazars ($z>2.5$) detected in the high energy $\gamma$-ray band are investigated by analyzing the {\it…
The NeXT (New exploration X-ray Telescope), the new Japanese X-ray Astronomy Satellite following Suzaku, is an international X-ray mission which is currently planed for launch in 2013. NeXT is a combination of wide band X-ray spectroscopy…
LOFT (Large Observatory For x-ray Timing) is one of the four missions selected in 2011 for assessment study for the ESA M3 mission in the Cosmic Vision program, expected to be launched in 2024. The LOFT mission will carry two instruments…
The study of astronomical transients at high energies provides insights into some of the most extreme physical events in the universe; however, carrying out their detection and fast follow-up studies are limited by instrumental constraints.…
We report here on the recent results of a monitoring campaign we have been carrying out with Swift/XRT on a sample of four Supergiant Fast X-ray Transients. The main goal of this large programme (with a net Swift/XRT exposure of 540 ks,…
We present our sixth work in a series dedicated to variability studies of active galactic nuclei (AGN) based on the survey of the COSMOS field by the VLT Survey Telescope (VST). Its 54 r-band visits over 3.3 yr and single-visit depth of…
The observation of Very High Energy gamma rays (VHE, E > 100 GeV) led us to the identification of extremely energetic processes and particle acceleration sites both within our Galaxy and beyond. We expect that VHE facilities, like CTA, will…
The Microchannel X-ray Telescope (MXT) is an innovative compact X-ray instrument on board the SVOM astronomical mission dedicated to the study of transient phenomena such as gamma-ray bursts. During 3 weeks, we have tested the MXT flight…
The super-massive black-holes in the centers of Active Galactic Nuclei (AGNs) are surrounded by obscuring matter that can block the nuclear radiation. Depending on the amount of blocked radiation, the flux from the AGN can be too faint to…
SVOM is a Sino-French space mission targeting high-energy transient astrophysical objects such as gamma-ray bursts. The soft X-ray part of the spectrum is covered by the Micro-channel X-ray Telescope (MXT) which is a narrow field telescope…
The survey of the COSMOS field by the VLT Survey Telescope is an appealing testing ground for variability studies of active galactic nuclei (AGN). With 54 r-band visits over 3.3 yr and a single-visit depth of 24.6 r-band mag, the dataset is…
We present a method that enables wide field ground-based telescopes to scan the sky for sub-second stellar variability. The method has operational and image processing components. The operational component is to take star trail images. Each…
Past and current X-ray mission allow us to observe only a fraction of the volume occupied by the ICM. After reviewing the state of the art of cluster outskirts observations we discuss some important constraints that should be met when…
My Ph.D. Thesis is devoted to the study of groups and clusters of galaxies in the X-ray band. This field has been very active in the last ten years, thanks to the data gathered from the Chandra and XMM satellites. Clusters of galaxies are…
The wide fields of view, high sensitivity, and broad energy coverage of current X-ray and gamma-ray satellites, coupled with the high cadence observational strategy of some of them (recently Swift and Fermi) have been ideal for carrying out…
Gamma-ray bursts (GRBs) are a promising probe of the high-redshift Universe, but their detection remains observationally challenging. In this work, we explore the detectability of high-$z$ GRBs by the Wide-field X-ray Telescope (WXT) aboard…
Supergiant fast X-ray transient (SFXT) is a new class of the high mass X-ray binary that shows short X-ray flares. The physical mechanism of SFXT short flares is still open for discussion. The accretion process of dense clumps in stellar…
We report on the Swift/X-ray Telescope (XRT) monitoring of the field of view around the candidate supergiant fast X-ray transient (SFXT) IGR J17354-3255, which is positionally associated with the AGILE/GRID gamma-ray transient AGL…
The SXI telescope is one of the three instruments on board EXIST, a multiwavelength observatory in charge of performing a global survey of the sky in hard X-rays searching for Supermassive Black Holes. One of the primary objectives of EXIST…