Oberto Citterio

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The Swift mission, scheduled for launch in 2004, is a multiwavelength observatory for gamma-ray burst (GRB) astronomy. It is a first-of-its-kind autonomous rapid-slewing satellite for transient astronomy and pioneers the way for future rapid-reaction and multiwavelength missions. It will be far more powerful than any previous GRB mission, observing more(More)
High groove density reflection gratings placed at grazing incidence in the extreme off-plane mount offer increased performance over conventional in-plane mounts in the x-ray. We present initial off-plane efficiency test results from the grating evaluation facility at the University of Colorado. The test gratings are holographically ruled, ion-etched(More)
While the energy density of the Cosmic X-ray Background (CXB) provides a statistical estimate of the super massive black hole (SMBH) growth and mass density in the Universe, the lack, so far, of focusing instrument in the 20-60 keV (where the CXB energy density peaks), frustrates our effort to obtain a comprehensive picture of the SMBH evolutionary(More)
X-Ray Polarimetry can be now performed by using a Micro Pattern Gas Chamber in the focus of a telescope. It requires large area optics for most important scientific targets. But since the technique is additive a dedicated mission with a cluster of small telescopes can perform many important measurements and bridge the 40 year gap between OSO-8 data and(More)
Development of multi-layer optics makes feasible the use of X-ray telescope at energy up to 60-80 keV: in this paper we discuss the extension of photoelectric polarimeter based on Micro Pattern Gas Chamber to high energy X-rays. We calculated the sensitivity with Neon and Argon based mixtures at high pressure with thick absorption gap: placing the MPGC at(More)
To date, the diagnosis of acute appendicitis (AA) has been made primarily on clinical grounds and imaging techniques have been considered less useful. This paper is aimed at evaluating US utility in the diagnosis of AA. US scans of the appendix, after Puylaert, were obtained in 30 healthy subjects (group A), in 49 patients with recurrent pain in the iliac(More)
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 in response to the 2004 call for ideas of CNES for a scientific mission to be flown on a formation flying demonstrator. Relying on two spacecrafts in a formation flying configuration, SIMBOL–X uses for the first time a ~ 30 m(More)
The Nuclear Spectroscopic Telescope Array (NuSTAR) is a small explorer (SMEX) mission currently under an extended Phase A study by NASA. NuSTAR will be the first satellite mission to employ focusing optics in the hard X-ray band (880 keV). Its design eliminates high detector backgrounds, allows true imaging, and permits the use of compact high performance(More)
The next generation wide-field X-ray telescope (WFXT), to be implemented beyond eRosita and proposed within the NASA RFI call 2011, requires an angular resolution of less than 10 arcsec (with goal of 5”) constant across a wide field of view (1 deg). To achieve this requirement the design is based on nested modified grazing incidence Wolter-I mirrors with(More)
The scientific instrumentation onboard the Italian satellite for x-ray astronomy (SAX) foresees x-ray imaging concentrators operating in the 0.1-10-keV energy range with a spatial resolution of 1 min of arc. The optics is composed of thirty confocal-nested very thin double-cone mirrors. To achieve good optical quality and to allow the construction of(More)