Swift X-Ray Telescope

Abstract

The Swift Gamma Ray Burst Explorer will be launched in 2003 to observe hundreds of gamma-ray bursts per year and study their X-ray and optical afterglows, using a multiwavelength complement of three instruments: a wide-field Burst Alert Telescope (BAT), an X-Ray Telescope (XRT), and a UV/Optical Telescope (UVOT).The XRT is designed to study X-ray counterparts of the gamma-ray bursts and their afterglows, beginning 20-70 s from the time of the burst, and continuing for days or weeks. The XRT utilizes a superb mirror set built for JET-X 1 and a state-of-theart XMM/EPIC CCD detector 2,3 to provide a sensitive broad-band (0.2-10 keV) X-ray imager with effective area of 110 cm 2 at 1.5 keV, field of view of 23.6 x 23.6 arcminutes, and angular resolution of 15 arcseconds (HEW). The sensitivity is 2x10 -14 erg/cm 2 /s in 10 4 seconds. The telescope electronics are designed to provide automated source detection and position reporting, with a position good to 2.5 arcseconds transmitted to the ground within 100 seconds of the burst detection. The XRT will operate in an auto-exposure mode, adjusting the CCD readout mode automatically to optimize the science return for each frame as the source fades. The XRT will measure spectra and lightcurves of the GRB afterglow beginning within about a minute after the burst and will follow each burst until it fades from view, typically monitoring 2-3 "old" bursts at a time while waiting for a new burst to be detected.

The Arcminute Microkelvin Imager catalogue of gamma-ray burst afterglows at 15.7 GHz

“…With the launch of Swift in 2004, the improved ability to localise GRBs to within 4 (Krimm et al 2013) using the Burst Alert Telescope (BAT; Barthelmy et al 2005), with more precise localisation being provided by the Swift X-ray Telescope (XRT; Burrows et al 2000) and the Swift Ultraviolet/Optical Telescope (UVOT; Roming et al 2005), has allowed back into the relativistic ejecta causing a much faster flash of emission . The transient radio emission associated with the reverse-shock occurs within a few hours to a few days post-burst (Kulkarni et al 1999), and therefore requires a rapid observing response in order to be detected.…”

The effect of proton damage on the X-ray spectral response of MOS CCDs for the Swift X-ray telescope

“…The XRT is a sensitive, flexible, autonomous X-ray CCD imaging spectrometer designed to measure the position, spectrum, and brightness of gamma-ray bursts (GRBs) and afterglows over a wide dynamic range covering more than seven orders of magnitude in flux [4,5]. An x-ray spectroscopy capability enables the determination of the redshift of the GRB if any spectral lines are visible in the x-ray afterglow [4,5].…”

“…The Swift X-ray Telescope (XRT) is part of the Swift Gamma Ray Burst Explorer, which is a three-telescope space observatory for studying the position, brightness, and physical properties of gamma ray bursts [4,5].…”

“…The Swift X-ray Telescope (XRT) is part of the Swift Gamma Ray Burst Explorer, which is a three-telescope space observatory for studying the position, brightness, and physical properties of gamma ray bursts [4,5] The XRT is a sensitive, flexible, autonomous X-ray CCD imaging spectrometer designed to measure the position, spectrum, and brightness of gamma-ray bursts (GRBs) and afterglows over a wide dynamic range covering more than seven orders of magnitude in flux [4,5]. An x-ray spectroscopy capability enables the determination of the redshift of the GRB if any spectral lines are visible in the x-ray afterglow [4,5].…”

“…An x-ray spectroscopy capability enables the determination of the redshift of the GRB if any spectral lines are visible in the x-ray afterglow [4,5]. The required spectral resolution is 300 eV at 6.4 keV for the three year mission lifetime [4,5].In order to accomplish this, the x-ray response of the CCD as a function of non-ionising damage must be …”