Swift 1 Swift Spacecraft and Instruments

Swift 2 Spacecraft Design 1 of 6 Reaction wheels Gyros Star Trackers

Swift 3 Swift Overview Catching Gamma Ray Bursts on the Fly Capabilities ¥~ 1000 GRBs studied over a three-year period ¥0.3–2.5 arc-second positions for each GRB ¥Multiwavelength observatory (gamma, X-ray, UV, and Optical) to monitor afterglows ¥20–70 s reaction time ¥Five times more sensitive than BATSE ¥Spectroscopy from 0.2 to 150 keV ¥Six colors covering 170–650 nm ¥UV and optical spectroscopy with R ~ 300–600 for M b < 17 ¥Capability to directly measure redshift ¥Results publicly distributed within seconds

Swift 4 Swift Mission Features ¥Multi-wavelength observatory ÑBurst Alert Telescope (BAT): keV ¥detect ~ 300 gamma ray bursts per year ¥onboard computation of positions ¥arc-minute positional accuracy ÑDedicated telescopes for X-rays, UV, and optical afterglow follow up: ¥ keV X-ray Telescope (XRT) ¥ nm UV/Optical Telescope (UVOT) ¥ arc-second locations ¥existing hardware from JET-X and XMM  determine redshifts from X-ray absorption, lines, and Lyman-  cutoff ¥Rapid response satellite Ñ sec to slew within FOV of BAT ¥autonomous operations ¥factor of > 100 improved response time ¥continue monitoring of fading afterglow for days to weeks after the event

Swift 5 Swift Instrumentation ¥Real time gamma ray burst positions Ñhalf coded 2 steradian FOV Ñ5200 cm 2 CdZnTe pixel array Ñ10–150 keV band Ñbased on INTEGRAL Imager design Ñ5 times more sensitive than BATSE Ñ~ 1 burst per day detected (depends of logN-logS extrapolation) Ñangular resolution of 22 arc-minute giving positions of 1–4 arc-minute Ñonboard processing to provide prompt arc-minute position to satellite ACS and to the ground I. Burst Alert Telescope (BAT) BAT CdZnTe 8 x 16 element detector module 4 mm

Swift 6 Swift Instrumentation II. X-ray Telescope (XRT) ¥Flight spare JET-X module ¥15 arc-second half energy width Ñsharp core will yield arc-second locations ¥3.5 m focal length ¥Total effective area Ñ110 cm 2 at 1.5 keV Ñ65 cm 2 at 6 keV ¥CCD array covers keV band Ñuse spare XMM chip Ñ24 x 24 arc-minute field of view ÑCooled to -80 degrees C XRT Mirror Module

Swift 7 Swift Instrumentation ¥Based on XMM OM to minimize cost and risk ÑCovers 170 nm to 650 nm Ñ30 cm Ritchey-Chretien telescope Ñ24 mag in 1000 s with 17 arc-minute FOV ÑDetector is image intensified CCD array ÑUnique coverage s after burst trigger ÑPositions to 0.3 arc-seconds using onboard image registration ¥UVOT will be simple reproduction of XMM OM III. UV-Optical Telescope (UVOT) Filter Wheel XMM OM

Swift 8 UVOT Performance Wavelength Percent Transmittance Measured UVOT Response UV and optical grisms with  of 0.5 nm and 1.0 nm, respectively, for M b < 17 IUE type resolution UVOT Sensitivity For V = 20 B star in 1000 s get: UVW2680 cts UVM2800 cts UVW11000 cts Sensitivity to Ly-  cutoff: UVM1 - UVM2z ~ 1.5 UVM1 - UVM1z ~ 2 U - UVW1z ~ 2.7 B - Uz ~ 3.5 ¥Positions to 0.3 arc-seconds using onboard image registrations ¥Filters give spectral/color information and allow redshift determination from Lyman edge detection

Swift 9 Multiwavelength Cascade of Images Gamma Ray (arc-minute) X-ray (2.5 arc-second) UVOT (0.3 arc-second) HST, Keck, etc.

Swift 10 Observing Strategy ¥Allow both onboard and external triggers (from, e.g., INTEGRAL) ¥Slew to new burst as soon as possible ¥Follow all afterglows for as long as they are visible Ñtypically Swift will be monitoring a few afterglows