5.13 Spectroscopic Use of the Bright Object Aperture

Spectroscopic observations with the BOA have had very little demand over the past cycles. For that reason, it has been decided that spectroscopic observations with the BOA will not be supported at the level that is used for the PSA. Spectroscopic observations with the BOA should be performed only if the technical requirement and scientific justification are particularly compelling. Proposers should be aware of the following caveats regarding use of the BOA:

  • Further calibrations for the BOA will not be provided by STScI. Either users must determine that they can create calibration files from data in the HST Archive or they must obtain calibrations as part of their observations. Spectroscopic observations using the BOA will be calibrated by CalCOS, but will be based on reference files primarily derived for use with the PSA and will use a the new TWOZONE extraction algorithm described in Section 3.2.1 of the COS Data Handbook.
  • User support from STScI for observation planning, as well as data reduction and analysis, with the BOA will be limited. Users taking spectroscopic data with the BOA should be prepared to shoulder the increased burden of the planning, calibration, reduction, and analysis.
  • BOA observations with G130M and G160M will take place at LP4, while those with G140L will take place at LP3.

Phase I proposals that include spectroscopic use of the BOA must include a justification of why the science cannot be done with the PSA.