Search results for "X-ray astrophysics"
showing 3 items of 3 documents
Evidence for a resonant cyclotron line in IGR J16493-4348 from the Swift-BAT hard X-ray survey
2012
Resonant absorption cyclotron features are a key diagnostic tool to directly measure the strength of the magnetic field of accreting neutron stars. However, typical values for cyclotron features lie in the high-energy part of the spectrum between 20 keV and 50 keV, where detection is often damped by the low statistics from single pointed observations. We show that long-term monitoring campaign performed with Swift-BAT of persistently, but faint, accreting high-mass X-ray binaries is able to reveal in their spectra the presence of cyclotron features. We extracted the average Swift-BAT 15-150 keV spectrum from the 54 months long Swift-BAT survey of the high-mass X-ray source IGR J16493-4348. …
The Swift-BAT survey reveals the orbital period of three high-mass X-ray binaries
2011
A growing number of previously hidden Galactic X-ray sources are now detected with recent surveys performed by the Integral and Swift satellites. Most of these new sources eluded past surveys due to their large local X-ray extinction and consequent low soft X-ray flux. The Swift-BAT performs daily monitoring of the sky in an energy band (15-150 keV) which is only marginally affected by X-ray extinction, thus allowing for the search of long periodicities in the light curve and identification of the nature of the X-ray sources. We performed a period search using the folding technique in the Swift-BAT light curves of three Integral sources: IGR J05007-7047, IGR J13186-6257 and IGR J17354-3255.…
Development of the UV/ion shields for the Advanced X-ray Astrophysics Facility high-resolution camera (AXAF HRC)
1994
The Advanced X-ray Astrophysics Facility (AXAF) is a major NASA space observatory (launch 1998). One of its two focal plane detectors is the High Resolution Camera (HRC) assembly consisting of two microchannel plate (MCP) based detectors. Key components of the two HRC detectors are UV/Ion shields consisting of metalized sub-micron plastic membranes, designed to prevent UV light and low energy charged particles from reaching the detectors' sensitive surfaces. We discuss the design issues and present results of recent measurements and tests. Soft X-ray/UV transmission measurements have been conducted at the Space Science Laboratory (SSL), University of California at Berkeley, and at the Osser…