STIS Cycle-17 Calibration Phase-1 Last Revised: 9/04/2009 Proposal ID: 11865 Title: COS Flux Standard PI: Dr. Ralph Bohlin Co-I(s): Dr. Daniel J. Lennon, Dr. Charles R. Proffitt, Mr. Michael A. Wolfe --------------------------------------------------------------------------- # This section should be written with a GO audience in mind -- use # Calibration plans in WFPC-2 handbook as a guide. Purposes: Cross-calibration of STIS/COS in the UV. Measurement/Verification of CTE correction for the CCDs. The G430L observations will be made at the E1 position to minimize CTE loss and at the central position to constrain CTE models. CTE losses can be measured by comparing STIS fluxes to the hi-fidelity model flux distribution for LDS749B from Bohlin & Koester (2008, AJ). This two orbit program duplicates one of the three identical repeat visits in program 9631, which established the Standard star status of LDS749B. A valuable addition to this program would be one orbit to re-observe with G750L and verify the Red-Halo dependence of the CTE per Goudfrooij & Bohlin (STIS ISR 2006-03). As CTE losses will be greater than the previous G750L observations in 2001, a G750L spectrum of ~2000s is required to measure the red-halo upturn well in the 8000-10000A region.
