Phase I: 12082
Extending COS/G130M Coverage Down to 905 Å
|Purpose||These observations will provide detailed sensitivity, wavelength range, and resolution measurements for two new lower wavelength COS FUV G130M central wavelength settings (covering 905-1171Å).|
These new settings will extend COS/G130M coverage down to 905Å in two new bandpasses; 1021-1171Å (BLUE) and 905-1055Å (Ultra-BLUE). The modes are chosen to provide continuous coverage from 905Å to the existing coverage in the G130M/1291Å setting with approximately 30Å of overlap in each mode for cross-calibration purposes. No focus adjustments will be made for these settings, as this is deemed an unnecessary risk to COS. The existing focus position for the G130M/1291Å setting will be used.
These new modes have the potential to provide greater than FUSE sensitivity at moderate (3,000-5,000) resolution.
Two targets will be observed for two orbits each:
Both targets have been observed with COS/G130M, IUE, GALEX, HST+STIS and FUSE. The second target has been observed with EUVE, with flux measured down to 250 Å. WD0320-539 will be our primary flux standard for Segment B, REJ0503-289 will be our flux standard for segment A. Both targets will be used for wavelength calibration. The numerous narrow and broad lines in REJ0503-289 will be used for resolution measurements.
These observations will rely upon the exploratory observations of GD50 in another project for health and safety checking and exposure time calculations.
|Fraction GO/GTO Programs Supported||Unknown|
|Resources Required: Observation||4 External Orbit|
|Resources Required: Analysis||The COS IDT will perform all required analysis.|
|Products||STScI will assist in mode implementation and any required adjustments to CALCOS and the COS reference files.|
|Accuracy Goals||Resolution and sensitivity to 10%, wavelength scale to 100 km/s.|
|Scheduling and Special Requirements||Special commanding and lamp flashing will be required. New OSM1 mechanism positions will need to be patched during commanding, similar to what is currently performed for some grating-specific target acquisition parameters.|