wfpc2 filters after 16 years on orbit
DESCRIPTION
WFPC2 Filters after 16 Years on Orbit. P. L. Lim 1 , M. Quijada 2 , S. Baggett 1 , J. Biretta 1 , J. MacKenty 1 , R. Boucarut 2 , S. Rice 2 , & J. del Hoyo 2. 1 Space Telescope Science Institute 2 Goddard Space Flight Center. Motivations. Over 180k datasets during on-orbit operation - PowerPoint PPT PresentationTRANSCRIPT
WFPC2 Filtersafter 16 Years on Orbit
P. L. Lim1, M. Quijada2, S. Baggett1,J. Biretta1, J. MacKenty1, R. Boucarut2,
S. Rice2, & J. del Hoyo2
STScI Calibration Workshop 2010
1 Space Telescope Science Institute2 Goddard Space Flight Center
Motivations
• Over 180k datasets during on-orbit operation• Improve science calibrations
– In-band, red/blue leaks– Change in transmission, bandpass wavelength
• Distribute new filter transmissions on WFPC2 website (approx. Oct 2010)
• Publish results in Instrument Science Report
STScI Calibration Workshop 2010
Known Changes• F122M
– 20-25% throughput drop (Biretta & Gonzaga 2008; private communications)
• F160BW– Pinhole growth (WFPC2 ISR 2009-01)
• F343N– 50% throughput drop (WFPC2 ISR 2009-02)
• Most filter changes expected to be less than a few percent
STScI Calibration Workshop 2010
Filters of Interest• Known on-orbit changes
– F122M, F160BW, F343N• High utilization
– F300W, F450W, F555W, F606W, F675W, F702W, F814W, F850LP• Regular utilization
– F255W, F336W, F439W, F502N, F656N, F658N, F673N• UV filters (red leak, pinholes)
– F170W, F185W, F218W• Others
– F130LP, F160AW, F165LP, F375N, F380W, F390N, F437N, F467M, F469N, F487N, F1042M, ramp filters
STScI Calibration Workshop 2010
Methods
• Cosmetic inspections (completed)– Stains, spots, pinholes
• Scan filter transmissions with spectrophotometer at GSFC– λ > 2000Å, Δλ ~ 0.5-50Å
• Compare with pre- and in-flight data
STScI Calibration Workshop 2010
Five-Point Scan
STScI Calibration Workshop 2010
F343N
STScI Calibration Workshop 2010
• Confirms photometry results (Gonzaga & Biretta 2009)• λpeak ~ 2Å redder, FWHM ~ 3Å wider, uniform change
3432Å
3434Å
F160AW, F160BW
STScI Calibration Workshop 2010
• AW → Not used in-flight due to pinholes• BW → Pinholes now worse than AW, spatially dependent• Will investigate when BW changes happened
(Log
sca
le)
F450W
STScI Calibration Workshop 2010
• Consistent with pre- and in-flight data
(Log
sca
le)
F170W
STScI Calibration Workshop 2010
• Red leak consistent with pre- and in-flight
(Log
sca
le)
Summary
• Goal is to improve science calibrations• Inspections and scans are performed• Early results are presented here
– F343N, F160AW, F160BW, F450W, F170W• Work is on-going and expected to be
published in Oct 2010
STScI Calibration Workshop 2010
Thank you