1. STIS Status TIPS, September 17, 2009 Charles Proffitt for the STIS team

2. STIS Status: Topics STIS SMOV & Calibration Overview STIS CCD status summary NUV Dark current update

3. STIS SMOV Status All STIS SMOV observations complete as of September 6, 2009 Most STIS SMOV analysis complete –Final superbias & super-dark reference files for SMOV period have been delivered –New CCD reference file delivered Readnoise, gain, and CTE parameters –CCD TDS reference files delivered Time-dependent sensitivity corrections to flux calibration Open issues in STIS SMOV analysis –Waiting for additional Cycle 17 calibration observations to finalize MAMA TDS updates Changes from pre-repair predictions appear to be small (< 3%) – Monitoring of NUV MAMA dark is being continued by cycle 17 calibration program 11857 –Detailed writeups still pending for most activities

4. STIS ActivityPropIDSTIS SMOV Program TitleAnalysis Lead Visits Done Total Visits Status STIS0211347Memory Load and DumpBS11Complete STIS0311348Science Data Buffer CheckBS33Complete STIS0411349Mechanism Mini-FunctionalTW11Complete STIS0511399CCD Anneal (two anneal iterations)MW66Complete STIS0611382CCD FunctionalDL44Complete STIS0711404CCD Dark & Bias MonitorMW90105Complete STIS0811383Aperture Wheel & Lamp FunctionalWZ22Complete STIS0911384STIS-to-FGS AlignmentCP11Complete STIS1011385CCD Spectral Format VerificationWZ11Complete STIS1111386External Focus CheckCP43+1Complete STIS1211387Corrector and Focus AlignmentCP-8Contingency STIS1311388CCD External Spectroscopic QualityTG11Complete STIS1411400CCD CTI CheckPG11Complete STIS1511401CCD Spectroscopic ThroughputsDL33Complete STIS1611389CCD Image and Pointing StabilityTG11Complete STIS1711350FUV MAMA HV RecoveryTW44Complete STIS1811351NUV MAMA HV RecoveryTW4 (+2F) Complete STIS1911390FUV MAMA Dark MeasureCP10 Complete STIS2011402NUV Dark MonitorCP42(+3F)20+52Complete STIS2111391FUV Optical Format VerificationWZ22Complete STIS2211392NUV Optical Format VerificationWZ2 (+2F) Complete STIS2311393FUV MAMA Spectroscopic QualityTG11Complete STIS2411394NUV MAMA Spectroscopic QualityTG11Complete STIS2511403MAMA Spectroscopic ThroughputsDL33Analysis being finalized STIS2611395MAMA Image StabilityTG22Complete

5. STIS Cycle 17 Calibration Analysis leads assigned for all programs –New leads will also track execution Most Calibration Programs have started –Routine dark monitors have begun Routine delivery of weekly bias and dark reference files –Automated Bias & Dark Pipeline still under work –P-flat data collection has begun SMOV plan deferred this calibration to cycle 17 –Data being combined with SMOV results to improve calibration Cycle 17 data especially important for CTE calibration

6. STIS Calibration Plan PropIDSTIS SMOV Program TitleAnalysis LeadStart Date 11843CCD Performance MonitorVD01-Sep-2009 11844/11845CCD Dark Monitor (part 1 & 2)MW03-Aug-2009 11846/11847CCD Bias Monitor (part 1 & 2)MW03-Aug-2009 11848CCD Read-noise MonitorVD10-Sep-2009 11849CCD Hot-pixel AnnealingMW23-Jul-2009 11852CCD Spectroscopic FlatsSN10-Aug-2009 11853CCD Imaging FlatsSN27-Aug-2009 11858CCD Spectroscopic DispersionIP20-Aug-2009 11850CCD Sparse Field CTE InternalVD03-Jul-2009 11854CCD Full Field SensitivityVDJan-Mar, 2010 11851Slit Wheel RepeatabilityWZ17-Aug-2009 11855CCD Spectroscopic Sensitivity MonitorRO10-Aug-2009 11859MAMA Dispersion SolutionsIP20-Aug-2009 11856MAMA Full Field SensitivityVDMay, 2010 11860MAMA Sensitivity and Focus MonitorRO03-Sep-2009 11857MAMA Dark MonitorWZ09-Sep-2009 11863MAMA Fold DistributionTWNov, 2009 11861MAMA FUV FlatsTA17-Aug-2009 11862MAMA NUV FlatsTA17-Aug-2009 11864MAMA Anomalous RecoveryTWcontingency 11865COS Flux StandardRBOct, 2009 11866Echelle Grating Blaze Function Zero PointsPGNov, 2009 11999JWST Calibration from a Consistent Absolute Calibration of Spitzer & Hubble RBOct, 2009 - Sep 2010

7. STIS CCD Status Dark current, read-noise, and CTE measured Read noise slightly greater than pre-repair –Gain = 1 was 5.3 now 5.8 e - –Gain = 4 was 7.8 now 8.3 e - Observed charge Transfer Efficiency (CTE) in 2009 close to extrapolation of old trend (CTI = 1 - CTE). –CTE losses becoming very large for faint sources

8. STIS CCD Status - cont Current pipeline CTE algorithm assumes constant “spurious charge” over detector at a given time –Can get better CTE correction if this allowed to vary over detector –This will require modest changes to CALSTIS –For now will use compromise value with old algorithm

9. CCD Dark Current Behavior Median CCD dark current in 2009 slightly above extrapolated trend from 2004 CCD Dark shows increasing spatial dependence over time –about 40% lower near row 900 as compared to center of chip!

10. CCD Sensitivity Changes

11. Advantages of E1 position For many years, we have had defined “E1” positions for CCD near row 900 of STIS long slit –Closer to default readout amplifier –Reduced CTI losses –Reduced effective dark current –Less contamination by CTE tails of CR & hot pixels While we have advertised advantages of E1 position for years in IHB and other documentation, ETC does not distinguish between center and E1 posistion –GO need to manually estimate CTE losses Re-emphasize importance of using E1 position to GOs For cycle 19 ETC, should include variations in dark current & CTE as function of slit position

12. NUV dark update Post SM4 NUV dark current (black dots) much higher than expected –model as “expected dark” + “something extra” Model as the “expected dark” (orange curve below) declining according to old behavior + an extra component Ae -(  E/T) e -t/  “extra” term appears to have stronger T dependence (  E ≈ 1.8 eV vs 1.5 eV) Plot below compares different e-folding times for extra component   =100 d (red) &  = ∞ (blue)