Raw image from VIMOS

The four detectors of VIMOS collected the many spectra produced by its integral field spectrograph. In a traditional image, the intensity of each pixel is recorded. Here, the full spectrum of each “pixel” of the image is recorded as a vertical line, measuring the intensity of the light for all wavelengths. specially written data analysis software is then used to extract all these spectra and re-order the information into something usable by the astronomer.