Image StabilityImage StabilityImage StabilityImage Stability

ACS SMOV image stability test (prop 9017) went from a cold soak (anti-solar pointing) for 8 orbits to a hot attitude (including off-nominal roll)– Nominal jitter (typically about 3 mas RMS

and 10 mas peak-to-peak) – Smooth drift at rates up to about 6 mas/hr in

both the HRC and WFC (same direction). – Drift may be due to FGS's or to rigid body

movement of the ACS wrt the OTA– Similar to image drift rates for other SIs.

Calibration – Flat FieldsCalibration – Flat FieldsCalibration – Flat FieldsCalibration – Flat Fields

L-flat for the F555W filter, the plot is a 4th order least-squares fit to the stellar photometry. – ~10% gradient from upper left to lower

right– (Mack, van der Marel, Bohlin, Blakeslee,

Cox)

Flat field – Sanity ChecksFlat field – Sanity ChecksFlat field – Sanity ChecksFlat field – Sanity Checks

Ratio of the F555W photometry in the CRJ to the DRZ image, corrected for distortion. – White is 1.10 and black is 0.93.

Pixel Map from Geometricdistortion – ratio produces 1% residual

SensitivitySensitivitySensitivitySensitivity

0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2

F220W

F250WF330W

F344N

F435WF475W

F502N

F550M

F555WF606W

F625W

F658NF660N

F775W

F814WF850LP

F892N

• Inflight sensitivity vs prediction from components

0.85 0.95 1.05 1.15 1.25

F435W

F475W

F502N

F550M

F555W

F606W

F625W

F658N

F660N

F775W

F814W

F850LP

F892N

HRC WFC

WFC Distortion CalibrationWFC Distortion CalibrationWFC Distortion CalibrationWFC Distortion Calibration

• 4th order 2D polynomial fit matches observed distortion well - RMS residual 1.1 mas (.02 px) - peak deviation ~ .2 px

WFC CCD Amplifier Cross-talkWFC CCD Amplifier Cross-talkWFC CCD Amplifier Cross-talkWFC CCD Amplifier Cross-talk

• Low-level “ghosts” of extended objects mirrored in alternate quadrants• Slight “droop” (fractional e-) in bias level of all 3 alternate amps• Ghosts do not appear to be proportional to target signal

Hard (2 e-) stretch ofWFC UGC10214 image

WFC: Long wave haloWFC: Long wave haloWFC: Long wave haloWFC: Long wave halo

B acks id e i llu m in ate d,th in n ed C C D (~1 5 m )

S od a g lass h ead er200 0 m

He ad er m eta liz atio n

CC D Pac kage Cro ss -se ction

Al metal layer reflects long- photons

F814w F850LP

WFC: Long wave haloWFC: Long wave haloWFC: Long wave haloWFC: Long wave halo

F775W F850LP FR1016N - 996

FILTER ETC Measured 80%5x5 px 5x5 px Ensq (px)

F775W (I) 0.8 0.79 5.2F850LP (z) 0.76 0.68 7.1FR1016N-996 0.73 0.49 15

IR Encircled Energy Performance

Optical “Ghosts”Optical “Ghosts”Optical “Ghosts”Optical “Ghosts”

Two ghost features have been identified with >0.1% of target energy:

WFC CCD to window reflection produces pairs of elliptical ghosts with ~ 0.2% integrated energy

F660N [NII] filter produces halos with ~2% of integrated energy due to reflection between its surfaces

Cats-Eye Nebula

NGC 6543 (HRC)

[OII] 3727 [OIII] 5007 H

Ramp filter

Coronagraph performanceCoronagraph performanceCoronagraph performanceCoronagraph performance

• Target acquisition functions• executed proposal second time with dithering to determine optimum location under each occulting spot

Coronagraph Dither Coronagraph Dither ResultsResults

Coronagraph Dither Coronagraph Dither ResultsResults

Coronagraph PerformanceCoronagraph PerformanceCoronagraph PerformanceCoronagraph Performance

SBC – First Light ImageSBC – First Light ImageSBC – First Light ImageSBC – First Light Image

Globular star cluster NGC6681. This cluster, with [Fe/H] = -1.5, is rich in Blue Horizontal Branch stars.The image combines first light data taken with three filters F125LP, F150LP, and F165LP.

Solar Blind ChannelSolar Blind ChannelSolar Blind ChannelSolar Blind Channel

CALACSCALACSCALACSCALACS

• First generation updates to CALACS & PyDrizzle are complete, software is frozen for distribution in next STSDAS

•Includes ST-ECF AXE software for grism/prism

Mosaic generated from 18 images of 47 Tuc

HDF-N: i+ z & grism HDF-N: i+ z & grism HDF-N: i+ z & grism HDF-N: i+ z & grism

WFC - 2x i- 3x z orbits - “HDF overlay”

Grism: 3 orbits

HDF-N ACS Grism HDF-N ACS Grism examplesexamples

HDF-N ACS Grism HDF-N ACS Grism examplesexamples

Emission-line galaxy with continuum and knots - [OIII] 5007 and H 6563

Redshift z = 0.319 F814AB = 22.5

(WFC 2x i + 3x z orbits, 3 grism orbits)

HDF-N SN2002dc HDF-N SN2002dc HDF-N SN2002dc HDF-N SN2002dc

WFC 2x i + 3x z orbits, 3 grism orbits

Galaxy & SN z=0.475

• Identified from difference imaging with WFPC2 HDFN

HDF-N SN2002dcHDF-N SN2002dcHDF-N SN2002dcHDF-N SN2002dc

• Galaxy and SN at z=0.48

• SN mag. is 22.7 (i)

• Type I (probably Ia)

Galaxy & SN z=0.475

SN2002dd SN2002dd SN2002dd SN2002dd

Galaxyz=0.79

• Identified from extracted spectra !

SnIaz=1.06

HDF-N SN2002ddHDF-N SN2002ddHDF-N SN2002ddHDF-N SN2002dd

• Follow-up with DD proposal

Cool Image – A1689Cool Image – A1689Cool Image – A1689Cool Image – A1689

CourtesyACS Science Team

Image StabilityImage StabilityImage StabilityImage Stability