SMOV Absolute Flux Calibration of the COS NUV Modes
Abstract
Initial point source sensitivity curves are determined for the COS NUV gratings: G230L, G185M, G225M and G285M. Observations through the PSA were obtained of the standard star GD71 at all central wavelength settings of all the gratings. In addition, PSA observations of the standard star GRW+70°5824 were obtained at selected settings. Because the pipeline used at the time of the analysis extracted BOA spectra incorrectly, BOA calibrations are not discussed here. The accuracy of the calibration is estimated to be 2% for the medium resolution gratings, and somewhat less accurate for portions of the G230L. We also examine the contributions of off-order light contamination on the observed spectra. We find this to be negligible for the medium resolution gratings and for first order G230L spectra at wavelengths shorter than 3200Å.
- Publication:
-
Instrument Science Report COS 2010-01(v1
- Pub Date:
- January 2010
- Bibcode:
- 2010cos..rept....1M
- Keywords:
-
- Hubble Space Telescope;
- HST;
- Space Telescope Science Institute;
- COS;
- Cosmic Origins Spectrograph