Handbook Structure

The COS Data Handbook is organized in five chapters, which discuss the following topics:

  • Chapter 1: COS Overview provides a brief overview of the instrument and its operational capabilities.
  • Chapter 2: COS Data Files describes the contents of COS data files, the meanings of selected header keywords, and the relationship of the data products to the original Phase II proposal.
  • Chapter 3: COS Calibration describes how the calibration pipeline processes observations, the content of COS reference files used during calibration, and how to run the calibration pipeline locally.
  • Chapter 4: COS Error Sources describes the sources of uncertainty and limiting accuracies of COS data. COS observers should read this chapter to acquaint themselves with the limitations of the data that may remain after pipeline calibration.
  • Chapter 5: COS Data Analysis describes how to analyze COS data with Python using stenv, as well as other Python libraries useful for optimizing data products and analyzing the data. It describes how to analyze target acquisitions and guide star tracking. It provides descriptions of different kinds of data and gives detailed instructions on how to work with them; specifically: extracted spectra, and TIME-TAG data.

Additional help with HST data is always available via the STScI Help Desk at http://hsthelp.stsci.edu or by email to help@stsci.edu.
Readers are advised to consult the COS web pages (http://www.stsci.edu/hst/instrumentation/cos) for the latest news and updates on COS performance.