WFC3 SMOV Report for TIPS 16 July 2009 John MacKenty This presentation contains material that is embargoed until after the SM4 ERO press conference. Images/spectra of external (astronomical) objects may not be altered, distributed, reproduced, published, displayed, or used in any other way without the consent of the STScI Director or the HST Project.

WFC3 Activities IR Zero Points – P330E and GD153 standard stars (Visits 11,21) –Series of short exposures of White Dwarf standard star GD153 (hot source) Solar analog P330E (cool source) Both about V = 13.0 –All IR Filters exposed in RAPID plus narrow filters in SPARS10 –IRSUB128 used Target was close (2.5”) to corner but OK –Two sets of exposures obtained –Preliminary conclusion: IR photometry is 10-15% better than expected UVIS Flat Field Uniformity – very nice dataset on Omega Cen UVIS Shutter Test – data being analyzed

PRELIMINARY IR Throughput

WFC3 SMOV Progress WFC3 has 43 distinct SMOV Activities following SM4 Three phases: –Engineering Complete except for TEC setpoint verification ongoing Instrument performance nominal –Optical Alignment Both channel alignment/focus activities complete Verification follows OTA move on Day 201 –Science performance and calibration verification This week completing items for ERO and “EASY” science enable Most WFC3 ERO’s on 201 and 208 SMSs (208 also first science!) Except to complete SMOV in mid-late August

Engineering Tests Activation – repeat of FT and TEC cooldowns (11 June) Memory and Science Data Buffer Tests UVIS and IR Detector Functional Tests –Demonstrated expected readnoise and gain in both channels Channel Select Mechanism Test (aka First Light) –Beam is clear of obstructions and CSM repositions correctly UVIS SOFA and IR FSM tests –SOFA has shown 1 step offset in Wheel 10 – minor issue UVIS and IR Tungsten primary and spare lamp tests UVIS Contamination monitor UVIS Anneal UVIS and IR TEC performance –Still working thermal models to verify WFC3 can hold detector operating temperatures throughout Cycle 17: TECFIRE DB is close

Optical Alignment UVIS –Initial and Fine Alignment activities completed –Four iterations of focus and tip/tilt adjustment –Lost (and repeated) on visit due to Guide Stars –UVIS focus mechanism shows some “wobble” –Final tip/tilt run has best image (minimize coma) in corner of box IR –Initial and Fine Alignment activities completed ( 5 iterations) –Best image quality and EE achieved WFC3 chief ray angle was off by about 1 arc min (expected 10-15”) Both focus mechanisms near center of range Intentional defocus of 2.5 microns to be confocal with ACS/WFC –Move to nominal focus on Day 201 with OTA move of 3 microns Detailed image characterization (EE and PSF Wings) on 208 SMS

UVIS Science Performance and Calibration Verification Bias, Darks, CTE – nominal, early results show ACS trend of CTE Hot pixel trending unclear – first anneal proceeded by SI C&DH INT flats looking good – droplets unchanged since TV3 FGS SIAF update in work SAA passage test OK “bowtie” (i.e. QEH mitigation working well <0.5% residual) Upcoming events: –plate scale, L-flat verification –shutter timing and jitter tests –Pointing stability and D2 lamp tests Throughput results look good

PRELIMINARY UVIS Throughput

IR Science Performance and Calibration Verification Darks –Discovered light leak when HST pointed at bright earth –Likely fix is to position CSM in UVIS position (being tested) –Base dark is very good FGS SIAF update in work SAA passage test OK Upcoming events: –plate scale, L-flat verification –Pointing stability –Grism verification Throughput results look good

IR Dark as function of pointing

PRELIMINARY IR Throughput