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		| Paper: | 
		Concurrent Science and Wavecal COS Data | 
	 
	
		| Volume: | 
		347, Astronomical Data Analysis Software and Systems XIV | 
	 
	
		| Page: | 
		464 | 
	 
	
		| Authors: | 
		Hodge, P.E. | 
	 
	
	
		| Abstract: | 
		Wavelength calibration for the Cosmic Origins Spectrograph (COS) is achieved by taking an exposure (a wavecal) of an internal emission-line lamp and comparing the observed location with the expected location. In order to correct for possible mechanism drifts during exposures which can be more than an hour long, a new observing mode has been proposed whereby the line lamp would be turned on briefly several times during a science exposure. This is practical because the science and wavecal spectra fall on different parts of the detector, and because COS data will normally be taken in time-tag mode, where the time and pixel coordinates are recorded for each detected photon. This paper describes the calibration of such data. | 
	 
	
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