Technical Specifications
The Oxford SWIFT spectrograph is an image slicer based integral field spectrograph that provides simultaneous spectroscopy of every spatial pixel (spaxel) of a contiguous field of 44 × 89 spaxels. The spaxel size can be chosen "on-the-fly" to suit the PSF provided by the telescope and the adaptive optics system.
Pixel Scales: One of 0.235″/spaxel, 0.080″/spaxel or 0.016″/spaxel.
Field of View: The SWIFT field of view always retains a ∼1:2 aspect ratio, with 44 × 89 spaxels. The field of view merely scales with the spaxel size.
Wavelength Range: 650 – 1000 nm instantaneous wavelength coverage in a single exposure (750 – 1000 nm with the 750 nm dichroic).
Spectral Resolution: R ≡ λ⁄Δλ = 3250 at 650 nm, rising linearly to 4400 at 1000 nm, 2 pixel spectral FWHM. The plot below shows the resolving power (black line, left hand scale) and slit width (red line, right hand scale) as a function of wavelength.
Detectors: SWIFT has twin spectrographs, each of which disperse on to a LBNL 250 μm thick, fully depleted, 4k × 2k CCD detector array, with enhanced red quantum efficiency, and negligible fringing. The plot below shows the LBNL CCD QE (blue line) compared with other CCDs. The atmospheric transmission is indicated by the gray line.
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