This is an example of a NIRSpec spectrum obtained during the ISIM CV-3 test campaign.
This spectrum is obtained using an instrument calibration source. Light from one of the internal lamps in NIRSpec passes through a filter selected specially for calibration. This results in sharp absorption lines that can be used to calibrate the wavelength response of the instrument.
NIRSpec can operate in four modes: MOS (multi-object spectroscopy), SLIT (high-contrast slit spectroscopy), IFU (integral field unit mode) and IMA (imaging mode). This spectrum was obtained with NIRSpec operating in MOS-SLIT mode.