 <unk> , short @-@ arc , high pressure xenon arc lamps have a color temperature closely <unk> noon sunlight and are used in solar simulators . That is , the <unk> of these lamps closely <unk> a heated black body <unk> that has a temperature close to that observed from the Sun . After they were first introduced during the 1940s , these lamps began replacing the shorter @-@ lived carbon arc lamps in movie <unk> . They are employed in typical 35mm , <unk> and the new digital <unk> film projection systems , automotive <unk> <unk> , high @-@ end " tactical " <unk> and other specialized uses . These arc lamps are an excellent source of short wavelength ultraviolet radiation and they have intense emissions in the near infrared , which is used in some night vision systems . 
