13353( 5) - 13-Aug-2013 17:14:04 - [ 1] HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 13353 Version: 5 Check-in Time: 13-Aug-2013 17:14:04 STScI Edit Number: 1 Title Flux calibration of the COS FUV modes ------------------------------------------------------------------------------------ Type Cycle GO 21 ------------------------------------------------------------------------------------ Investigators Contact? PI: Dr. Derck L. Massa Space Science Institute Y CoI: Dr. Ralph C. Bohlin Space Telescope Science Institute N CoI: Prof. Detlev G. Koester Universitat Kiel N ------------------------------------------------------------------------------------ Abstract We intend to use a model atmosphere for the DB white dwarf WD0308-565 to calibrate COS below 1150 Ang. This model has been vetted at longer wavelengths, where it has been shown to agree with previous DA calibrations. However, unlike the DA standards, WD0309-565 contains very little hydrogen. This eliminates uncertainties in the physics of the Lyman stark wings which affect virtually all wavelengths below 1100 Ang. As a result, it will provide a superior, less biased calibration for COS at these wavelengths. These same data will be used to produce fixed pattern templates for the new COS FUV settings. These can be used to reduce the effects of the COS fixed pattern noise. ------------------------------------------------------------------------------------ Observations Description ------------------------ We used the available STIS and FUSE spectra of WD0308-565 for the ETC calculations (COS.sp.490029 for CENWAVE 1055 and COS.sp.490065 for CENWAVE 1096). The exposure times are set by the counts on segment B (FUVB), since its wavelength coverage is short ward of the MgF2 cut off, where the COS response drops by a factor of 100. The ETC calculations show that in a 50 min. orbit, the count rate over the FUVB is relatively uniform at roughly 250 counts/resel/s = 0.0028/counts/pixel/s. Further, for 1055 and 1096 settings, the FUVB has a plate scale of ' 0:01A/pixel. Using these numbers, we see that we can achieve our primary goal of a S/N = 50/1 over 1A bins with four 50 min. orbits (one at each FPPOS) for each CENWAVE. These will give a S/N of 58/1/A. Real Time Justification ----------------------- Calibration Justification ------------------------- The goals of this proposal are straightforward: To produce a better FUV fux calibration for the COS FUV settings which is free of uncertainties due to Stark broadening of the Lyman lines and to develop a P-flat that will greatly enhance the data quality of all COS FUV data. Upon its completion, we will furnish STScI with sensitivity curves for the COS FUV CENWAVE 1055 and 1096 settings derived from the best available model atmosphere for the DB WD0308-565. We will also provide P-ats for these CENWAVEs. Because the P-flat 13353( 5) - 13-Aug-2013 17:14:04 - [ 2] is a 1-D correction for an inherently 2-D effect, a new P-flat must be determined for the FUV settings since they fall at a different cross-dispersion location on the detector than the traditional settings. The same observations used to derive the absolute fux calibration can be used to derive the P-ats as well, if adequate S/N is achieved. Additional Comments ------------------- ------------------------------------------------------------------------------------ 13353( 5) - 13-Aug-2013 17:14:04 - [ 3] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 WD-0308-565 CALIBRATION, RA=03H09M47.9200S +/- 0.5", J2000 V = 14.07 +/- 0.02 PHOTOMETRIC DEC=-56D23'49.41" +/- 0.5" Reference Frame: ICRS Comments: Coordinate information same as Prop 12795 Epoch of Position RA proper motion (seconds of time/yr) DEC Proper Motion (arcsec/yr) Annual Parallax (arcsec) 2000 0.01814126767953136 0.0643 0.0 ------------------------------------------------------------------------------------------------------------------------------------ 13353( 5) - 13-Aug-2013 17:14:04 - [ 4] Visit: 01 Visit Requirements: GROUP 01, 02 WITHIN 7D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WD-0308-565 COS/NUV ACQ/IMA BOA MIRRORA 1 50 S (50 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD-0308-565 COS/FUV TIME-TA PSA G130M 1055 FP-POS=2, BUFFER-TIME=1000 1 2400 S G (2400 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD-0308-565 COS/FUV TIME-TA PSA G130M 1055 FP-POS=3, BUFFER-TIME=1000 1 2900 S G (2900 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD-0308-565 COS/FUV TIME-TA PSA G130M 1055 FP-POS=4, BUFFER-TIME=1000 1 2900 S G (2900 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD-0308-565 COS/FUV TIME-TA PSA G130M 1055 FP-POS=1, BUFFER-TIME=1000 1 2900 S G (2900 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WD-0308-565 1 COS/NUV ACQ/IMA BOA MIRRORA none none none none 1 N/A GE WD-0308-565 2 COS/FUV TIME-TA PSA G130M 1055 none none none none 1 N/A G WD-0308-565 3 COS/FUV TIME-TA PSA G130M 1055 none none none none 2 N/A G WD-0308-565 4 COS/FUV TIME-TA PSA G130M 1055 none none none none 3 N/A G WD-0308-565 5 COS/FUV TIME-TA PSA G130M 1055 none none none none 4 N/A G 13353( 5) - 13-Aug-2013 17:14:04 - [ 5] Visit: 02 Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exp | Target | Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Num | Name | Config | Mode | or FOV |Element |Waveln.| Parameters |Exp| (Total) | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 WD-0308-565 COS/NUV ACQ/IMA BOA MIRRORA 1 50 S (50 GE S) ------------------------------------------------------------------------------------------------------------------------------------ 2 WD-0308-565 COS/FUV TIME-TA PSA G130M 1096 FP-POS=2, BUFFER-TIME=700 1 2400 S G (2400 S) ------------------------------------------------------------------------------------------------------------------------------------ 3 WD-0308-565 COS/FUV TIME-TA PSA G130M 1096 FP-POS=3, BUFFER-TIME=700 1 2900 S G (2900 S) ------------------------------------------------------------------------------------------------------------------------------------ 4 WD-0308-565 COS/FUV TIME-TA PSA G130M 1096 FP-POS=4, BUFFER-TIME=700 1 2900 S G (2900 S) ------------------------------------------------------------------------------------------------------------------------------------ 5 WD-0308-565 COS/FUV TIME-TA PSA G130M 1096 FP-POS=1, BUFFER-TIME=700 1 2900 S G (2900 S) ------------------------------------------------------------------------------------------------------------------------------------ Sub Exposures ------------------------------------------------------------------------------------------------------------------------------------ Target | Exp |Instr | Oper. | Aper |Spectral|Cent.|Primary |Secondary |Iteration |CR-SPLIT |Orbit |Duration Name | Num |Config | Mode | or FOV |Element |Wave.|Pattern Pos |Pattern Pos |Num |Num |Number | ------------------------------------------------------------------------------------------------------------------------------------ WD-0308-565 1 COS/NUV ACQ/IMA BOA MIRRORA none none none none 1 N/A GE WD-0308-565 2 COS/FUV TIME-TA PSA G130M 1096 none none none none 1 N/A G WD-0308-565 3 COS/FUV TIME-TA PSA G130M 1096 none none none none 2 N/A G WD-0308-565 4 COS/FUV TIME-TA PSA G130M 1096 none none none none 3 N/A G WD-0308-565 5 COS/FUV TIME-TA PSA G130M 1096 none none none none 4 N/A G 13353( 5) - 13-Aug-2013 17:14:04 - [ 6] Summary Form for Proposal 13353 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures BOA, PSA ------------------------------------------------------------------------------------------------------------------------------------ Configurations COS/FUV, COS/NUV ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ/IMAGE, TIME-TAG ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters BUFFER-TIME=1000, BUFFER-TIME=700, FP-POS=1, FP-POS=2, FP-POS=3, FP-POS=4 ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements GROUP 01, 02 WITHIN 7D ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements G130M, MIRRORA ------------------------------------------------------------------------------------------------------------------------------------ Target Names WD-0308-565 ------------------------------------------------------------------------------------------------------------------------------------