Chapter 5:
Spectroscopy with COS
5.1 Configurations and Optical Elements
5.2 Exposure Time Considerations
5.3 Apertures
5.4 TIME-TAG or ACCUM?
5.4.1 TIME-TAG mode
5.4.2 ACCUM mode
5.5 FUV gap coverage and single segment usage
5.6 Internal Wavelength Calibration Exposures
5.6.1 What "TAGFLASH" does during TIME-TAG observations
5.6.2 AUTO wavecals (when "Tagflash" is not used)
5.6.3 User-specified wavelength calibration exposures (GO wavecals)
5.7 Achieving Higher Signal-to-noise
5.8 EXTENDED
5.9 Calibrations
5.9.1 Internal calibrations
5.10 FUV Wavelength Settings And Ranges
This chapter describes COS spectroscopic observations. Both the FUV and NUV channels are used in essentially identical ways, but we point out the differences as appropriate. The discussion includes:
- Characteristics of
TIME-TAG and ACCUM observing modes.
- Details and effects of
BUFFER-TIME for TIME-TAG observing.
- General exposure time considerations.
- Characteristics of the FUV spectrum gap and how to fill it in.
- A description of the Optional Parameters that are a routine part of COS observing and their use in specific situations.
- A practical description of the TAGFLASH (
FLASH=YES) wavelength calibration feature.
- Using a single segment with the FUV channel.
- Obtaining the highest possible signal-to-noise with
FP-POS.
- A description of the various calibrations and what, if any, calibration observations the GO may perform.
- The use of the
EXTENDED optional parameter.
