|Space Telescope Science Institute|
|COS Instrument Handbook Cycle 23|
Due to low demand and the lack of sufficiently precise calibration data, as of Cycle 23 scientific spectroscopic observations taken with the Bright Object Aperture (BOA) will be considered “available-but-unsupported”. Spectroscopic observations using the BOA come at a price, and it should be used 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.
• User support from STScI for observation planning, as well as data reduction and analysis, with unsupported capabilities will be limited and provided at a low priority. Users taking data with unsupported capabilities should be prepared to shoulder the increased burden of the planning, calibration, reduction, and analysis.
4. During the Phase II proposal submission process, STScI must also formally approve your use of an available-but-unsupported mode. This allows STScI to evaluate your request and ensures that no problems associated with your request have come to light since the submission of your Phase I proposal. We require that you summarize the above four points in a brief email message requesting approval for use of an available-but-unsupported mode.The increased burden of calibrating data taken using available-but-unsupported modes also makes the use of such data for archival research significantly more difficult. As a result, requests for use of unsupported modes which do not adequately address the above four points, or which will result in only marginal improvements in the quality of the data obtained, may be denied by STScI, even if the request was properly included in your Phase I proposal.