LegacyArchivePoint Spread Function (PSF)LibraryAndCircumstellarEnvironments

INVESTIGATION (HST/AR 11279)

Glenn Schneider (University of Arizona)Murray Silverstone (Eureka Scientific), Joseph Rhee (UCLA),

Elizabeth Stobie (NOAO), Dean Hines (STScI)

NICMOS CORONAGRAPHY:Recalibration and the NICMOS Legacy Archive PSF Library

HUBBLE SPACE TELESCOPE

HST/NICMOS CORONAGRAPHY

With “Well Matched” PSF Template Subtraction Provides - Highest Imaging Contrast - at the Smallest Inner Working Angle (r = 0.3”) - with Full Circumferential (azimuthal) Coveage - very High Dynamic Range (multi-accum) Samplingof the 5 HST coronagraphically augmented SI’s

F110W_mag = 6.82J - H = +0.12 (A5V)

Typical Performance (F110W)

Image Contrast per Resel ~ 10-4 at 0.3”

~ few x 10-6 at 1”

~ 5 x 10-7 at 2”

Target (Orient 1) Template PSF Revealed CS Disk

Target (Orient 2) Template PSF Revealed CS Disk

– =

– =

But Has Been Difficult To Routinely Achieve

EXAMPLE: “The close environment of four old Pre-Main Sequence stars has been observed thanks to the coronagraphic mode of the HST/NICMOS2 camera at 1.6 m.

… The circumstellar disks around SAO 206462 and MWC 480 are not resolved.” - Augereau et al. 2001 A&A 265 78

BUT WITH LAPLACE RE-PROCESSINGMWC 480 SAO 206462 Grady et al. in prep Grady et al. 2009 ApJ 699 1822

PSF-Template Subtraction Efficacy Strongly Dependent Upon:

a) Chromaticity -- Target vs. Template Stellar SED in filter band

K7V (log PSF) K4V (log PSF) Difference (linear)

Contrast: 10-6 @1”

– =

(e.g. F160W; similar to H-band)

PSF-Template Subtraction Efficacy Strongly Dependent Upon:

b) “Wiggling” (Instability) of Decentered Pupil Stop

PSF-Template Subtraction Efficacy Strongly Dependent Upon:

c) OTA “Breathing”: WFE (primarily focus) and PSF stability on sub-orbit to orbit timescales

Same Target Difference Images

PSF-Template Subtraction Efficacy Strongly Dependent Upon:

d) Target Acquisition Precision

Same Target Re-Registered Difference Images(18 mas target decentering per scan step)

X-only Decentering

Y-only Decentering

The LAPLACE project provides this ensemble WITH:

1) the BEST calibrated basic data available for NICMOS coronagraphic imaging,

2) the BEST PSF-template “matching” library for coronagraphic imaging possible from NICMOS archival data,3) these data and augmenting analysis S/W to the community through the HST/MAST archive.

A LARGE ENSEMBLE of HIGH FIDELITY PSF Template is Needed To Tile These (a-d) Parameter Spaces to

“Match” to Science Observations for Efficacious PSF Subtraction

Illustration of PSF-Subtraction Diversity (and Optical Artifacts Induced)with Color, OTA Breathing, and Cold Mask Position “Mis-Matches”

Rigorous Reprocessing of ~ 8,800 Science Data Images from 46 NICMOS Coronagraphic Programs Executed in Cycles 7, 7N, 11-15 (all inclusive) + Selective Cy 16 Targets

LAPL: Basic Data (Exposure Level) Recalibration of High Contrast /High Dynamic Range PSF and Improve Photometric Efficacy and

Image Quality over OPUS Pipeline

7038, 7052, 7157, 7179, 7220, 7221, 7226, 7227, 7233, 7248,7329,7418, 7441, 7808, 7828, 7829, 7834, 7835, 7857, 7897, 7924, 8079,8979, 8983, 8984, 9693, 9768, 9834, 9845, 10147, 10167, 10176, 10177, 10228, 10244, 10448, 10464, 10519, 10527, 10540, 10560,10599, 10847, 10849, 10852, 11155

ALSO includes all supplemental direct (non-coronagraphic) imagingobtained in the above programs

• Dark FramesIndividually Matched to Science Data from Totality of All Raw Dark Data Available (i.e., usually not generic “library” or “model” darks)

Individual Exposures Optimized Calibration Reference Files

LAPL: Basic Data (Exposure Level) Recalibration of High Contrast /High Dynamic Range PSF and Improve Photometric Efficacy andImage Quality over OPUS Pipeline

Detector Thermal Variation

in Raw Dark Frames

When Available, Temperature Matched Raw Darks by SAMPSEQMake Better Reference Data than Library or “Model” Darks* *(± < 100 mK in Cy 7/7N; ± 50 mK in Cy 11 +)

LAPLACE Custom Dark Calibration OPUS Model Dark Calibration

• Flat Field Imprints• Zero-Point (“DC”) Offset• “Photometrically Challenged” Column

LAPLACE Custom Dark Calibration OPUS Model Dark Calibration

Raw Dark & Coronagraphic Imaging By Sample Sequence

Raw Dark & Coronagraphic Imaging By Sample Sequence

• Dark FramesIndividually Matched to Science Data from Totality of All Raw Dark Data Available (i.e., usually not generic “library” or “model” darks)

• Flat Fields: (1) High SNR Time/Temperature Matched by Epoch

Individual Exposures Optimized Calibration Reference Files

LAPL: Basic Data (Exposure Level) Recalibration of High Contrast /High Dynamic Range PSF and Improve Photometric Efficacy andImage Quality over OPUS Pipeline

QE (Flat-Field Ratios) Three Epochs (Temperatures) in Cycle 7

QE (Flat-Field Ratios) Three Epochs (Temperatures) in Cycle 7

F110W F160W

Multi-Epoch Observed (High SNR “Epochal” Flats)

Where sufficient observed flats span the range of science observations, flat field observations are divided into multi epoch bins and the science observations made within the time-span of the epochal bin is matched to its epochal flat.

CY7/7N:

3 Epochs: F110W, F160W, F222M

2 Epochs: F187W, F205W, all other Medium bands, and the 3 Polarizers

1 Epoch: all Narrow Bands

NCS: The boundary Dates are:

Day MJD JD String 0 52394.5739 2452395.074 30-APR-2002 13:46:21.99 250 52644.5739 2452645.074 5-JAN-2003 13:46:21.99 500 52894.5739 2452895.074 12-SEP-2003 13:46:21.99 1600 53994.5739 2453995.074 16-SEP-2006 13:46:21.99

Epoch 1 is between 0-250 if there are 3 (F110W, F160W, F165M), 0-500 if there are 2 (F180M), or all dates if there is 1

Epoch 2 is between 250-500 if there are 3 (F110W, F160W, F165M), > 500 if there are 2 (F180M)

Epoch 3 is > 500 if there are 3 (F110W, F160W, F165M).

• Dark FramesIndividually Matched to Science Data from Totality of All Raw Dark Data Available (i.e., usually not generic “library” or “model” darks)

• Flat Fields: (1) High SNR Time/Temperature Matched by Epoch (2) PLUS Contemporaneous -Bootstrapped “Hole Finding” Flats

Individual Exposures Optimized Calibration Reference Files

LAPL: Basic Data (Exposure Level) Recalibration of High Contrast /High Dynamic Range PSF and Improve Photometric Efficacy andImage Quality over OPUS Pipeline

The Problem With Epochal Flats

(full frame before bad pixel replacement)

Contemporaneous (F160W) Hole-Finding Flat “flatted” with Recommended (CDBS) LibraryFlat

0 1 6

The Problem With Epochal Flats

Band-Transformed Contemporaneous Flats for Small IWA Calibration

Band-Transformed Contemporaneous Flats for Small IWA Calibration

• Dark FramesIndividually Matched to Science Data from Totality of All Raw Dark Data Available (i.e., usually not generic “library” or “model” darks)

• Flat Fields:High SNR Time/Temperature Matched by EpochPLUS Contemporaneous -Bootstrapped “Hole Finding” Flats

• “Bad” Pixel Maps with Clipping Thresholds more appropriate for High Dynamic Range (coronagraphic) Imaging

Individual Exposures Optimized Calibration Reference Files

LAPL: Basic Data (Exposure Level) Recalibration of High Contrast /High Dynamic Range PSF and Improve Photometric Efficacy andImage Quality over OPUS Pipeline

Excessivly Hot PixelsExcess Dark Current in Shading & Amplifier Glow Subtracted STEP 64 1st differences (median of N observations of 64 second integration time)

AmpGlow derived from 10 SCAMRR NSAMP=25 exposures, subtracted

Excess dark = 64-second “first differences” dark value > median of surrounding 80 pixels in 9x9 box centered on each pixel.

Hot Pixels Flagged: excess Dark Current > 0.9 ADU/s (5 e-/s), thus excess noise in 64 seconds would be 1/2 the readnoise, and thus be a significant contribution of noise in > 64 seconds.

Assumes readnoise = 35 e- per read pair, gain = 5.4 e-/adu, dark excess in 64 seconds less than one-quarter of (35^2 / 5.4 ADU = 227 ADU / 64 s = 3.5 ADU/s) thus < 0.9 ADU/s

0.9 ADU/s on color bar at 90 (just to the left of 100)

This threshold is significantly larger than median DC ~ 0.05 ADU/s (0.25 e-/s)

Cycle 7: 36 Pixels flagged with excess dark > 0.9 ADU/s

NCS: 196 Pixels flagged with excess dark > 0.9 ADU/s.

Under-Responsive PixelsWe define as value in F222M {Lamps On - Lamps Off} flat-field

observation < 5 sigma in 9x9 box surrounding good pixels

143 Underresponsive pix in Cycle 7 era 214 Underresponsive pixels in the NCS era

Note: conservative 50% Full-Well linearity file used to re-process F222M flat observations.

• Dark FramesIndividually Matched to Science Data from Totality of All Raw Dark Data Available (i.e., usually not generic “library” or “model” darks)

• Flat Fields:High SNR Time/Temperature Matched by EpochPLUS Contemporaneous -Bootstrapped “Hole Finding” Flats

• “Bad” Pixel Maps with Clipping Thresholds more appropriate for High Dynamic Range (coronagraphic) Imaging

Individual Exposures Optimized Calibration Reference Files

LAPL: Basic Data (Exposure Level) Recalibration of High Contrast /High Dynamic Range PSF and Improve Photometric Efficacy andImage Quality over OPUS Pipeline

“Bad” Pixels Replaced via 2-D Gaussian Weighted InterpolationOf Good Neighbors with Dependent Weighting Kernel (correctionMap written into Data Quality Extension)

BAD PIXEL REPARATION

(Required prior to sub-pixel image “shifting” in trmplate PSF subtraction)

TARGTYPE: POINT_SOURCE EXTENDED_SOURCE DOUBLE_STAR CORON_DOUBLE FAINT_OBJ FAILED

TARGCNTR: CENTERED DECENTERED PERIPHERY UNOCCULTED OUTFOV NOTARGET UNSTABLE

PSFQUAL: OK SATURATED DEGRADED

FITS Keyword/Meta-Data Target Descriptors

TARSIAFX= 71.7696 / Target SIAF XTARSIAFY= 211.280 / Target SIAF Y J_2MASS = 6.84700 / 2MASS J Mag JE_2MASS= 0.0230000 / 2MASS J Uncertainty H_2MASS = 6.38000 / 2MASS H Mag HE_2MASS= 0.0180000 / 2MASS H Uncertainty K_2MASS = 6.24500 / 2MASS K Mag KE_2MASS= 0.0200000 / 2MASS K Uncertainty F180M_EF= 'N ' / XFORM Error Flag F180M_JY= 2.62857 / NIC2 BAND Flux CPHOTSTR= 'rn(icat(k93models,5200,0.0,4.49), band(h),6.380,vegamag)' / SYNPHOT XFORM

FITS Keyword/Meta-Data Astrometry & Photomertry

LAPLACE PSF-Subtraction, Image Combination and Analysis Tools

EXAMPLES…

HD 181327 PSF-SUBTRACTED IMAGES FROM DISCOVERY PAPER

HD 181327 PSF-SUBTRACTED IMAGES WITH LAPL REPROCESSING

HD 100546 DISCOVERY vs. LAPL REPROCESSED IMAGES

Coming Soon to aData Archive Near You…

The NICMOS Coronagraphic

Legacy Archive PSF Library