SMOVSMOV  ACS has now completed SMOV Program –Transitioned to interim calibration plan  Final SMOV programs –Further coronagraph calibration –Coronagraph EROs  Analysis by John Krist

Large Spot Small Spot F435WF606WF814W Variations with Wavelength

SMOVSMOV  Results –Occulter positions are stable (< 2 mas) on orbital timescales when the masks are kept in place. –Spots can shift by up to 6 mas between acquisitions (mostly in Y direction).  Proposed commanding changes –Target acquisition with coronagraph in place –Do not shutter with aperture door between alignments. Provided mirror protection during SMOV

CalibrationCalibration  New flat fields have been installed for WFC –Precision ~1% –Further improvements require skyflats –Require enough images for high S/N  Current priorities 1.HRC broadband flat fields (***) 2.HRC NUV earth flat fields (**) 3.Grism flats (ECF) (*) 4.SBC flat fields (*) 5.WFC/HRC Earth flats (UV & narrowband filters) (***)

WFC Sensitivity  Corrections to existing WFC synphot tables (based on GD71 and GRW70) –Filter Factor –F435W 1.23 –F475W 1.23 –F555W 1.16 –F606W 1.13 –F625W 1.13 –F775W 1.11 –F814W 1.09 –F850LP 1.02

WFC Sensitivity

HRC Sensitivity

SBC Sensitivity

Geometric Distortion  Need 4th order solution to meet 0.2 pix accuracy requirement. –rms <~ 0.05 pix all frames & detectors –Breathing effects <~ 0.1 pixels across WFC FOV –No color terms needed  King’s calibration proposal will provide final check of skewness –King expects 10x nominal IHB calibration –Handle stitching errors etc.  Bootstrap SBC check from HRC results.

CALACS/PyDrizzleCALACS/PyDrizzle  CALACS Version 4.1a (26-July-2002) and PyDrizzle Version 3.3 (12-Aug-2002) have been delivered to OPUS/DST for testing under OPUS14.1.  For CALACS 4.1a: – ACSREJ now correctly computes the error arrays and initial guess image  For PyDrizzle 3.3: –supports newer higher-order polynomial fits from IDCTAB

CALACS/PyDrizzleCALACS/PyDrizzle –Allows 'blot' and single-exposure drizzling –This enables tasks to be written to remove cosmic-rays using PyDrizzle, with 'multidriz' being the alpha-version of such a task. –Correctly computes (small) offsets by applying distortion to input WCS. This will dramatically improve the registration in OTFR products for a wide range of dithered observations. –Provides ability for arbitrary specification of output frame. Allows users to PyDrizzle their data for direct comparison with reference/ground-based/astrometric observations

ACS CTE Degradation: I Analysis of cosmic ray profiles: Riess

WFPC2 CTE Degradation

ACS Data Access

ACS Group  Welcome to two new group members –Shardha Jogee –Roland van der Marel  Chris O’Dea is moving to SPD