Edinburgh 11 th November 2005 UKIDSS Science Verification Summary/Highlights of SV effort to date...

Edinburgh 11 th November 2005 UKIDSS Science Verification Summary/Highlights of SV effort to date Simon Dye Data characteristics Survey-specific SV Data characteristics Survey-specific SV Data characteristics Read noise CDS dark Median filtered diff. img. Difference image Subtracted diff. img. Read noise & dark stability ArrayCDS r.o.n. CDS banding NDR r.o.n. NDR banding e-16.2 e-13.0 e-11.0 e e-12.0 e-14.7 e-7.9 e e-12.1 e-16.3 e-10.8 e e-15.7 e-19.9 e-9.5 e- NDR mode reduces r.o.n. and banding level by ~30% cf. CDS r.o.n. in CDS darks practically independent of t_exp NDR darks seem less stable than CDS Flatfields Average 1sigma variation in pixel response is ~14% Variation in array 4 is double that in array 1 Variation higher in shorter wavelength filters Flatfields Field lens still dirty => K band thermal emission Flatfields Variation in thermal emission seen between nights Variation of flatfield response, however, is small, ~1%, only marginally higher than Poisson noise 10/04/200511/04/2005 Flatfields Difference image Persistence Persistence after filter change much reduced but still present Flare Nov 2004 April 2005 Background limit Fractional increase = sqrt[ counts(e-) + (r.o.n)^2 ] / sqrt[ counts(e-) ] - 1 Background limit Fractional increase = sqrt[ counts(e-) + (r.o.n)^2 ] / sqrt[ counts(e-) ] - 1 Calibration Use observation of standard GD153 on 10/04/2005 Calibration Relative to Vega, mags of GD153: FilterSynthetic mag UKIRT faint std Z13.76 Y13.97 J H K Zero pt (ADU) Pipeline zero pt Survey specific SV LAS: SV target list LAS: Manual vs. pipeline photometry 7 LAS SV targets observed on night of 10/04/05: 2 BDs, 2 CWDs, 3 QSOs LAS: Manual vs. pipeline photometry Col-col diag for L3 BD & L4.5 BD CASU Manual LAS: Manual vs. pipeline photometry Col-col diagram for 2 z=6.1 QSOs CASU Manual LAS: Manual vs. pipeline photometry Calculate mag(pipeline) mag(manual) for objects where detected in each filter: => Pipeline mags are consistent: /- 0.08 LAS: Pipeline vs synthetic colours (Nick Lodieu) LAS: Number counts (Antony Smith, Sussex) YJ HK LAS: Astrometry (Antony Smith, Sussex) Distance from DR4 spec. gals GCS: Photometry (Tim Kendall, Herts) Comparison with 2MASS Systematics: point source/non point source MKO vs. 2MASS GCS: Internal consistency (Nigel Hambly, Edinburgh) ( ), 5yr, K=18: 30mas/yr x2 better required microstepping PSF fitting LAS: Internal consistency in K =1.53 LAS: K band, SExtractor vs. pipeline UDS: Stacking tests (Omar Almaini, Seb Foucaud, Notts) ELAIS N1, Full stacked tile, 17K x 17K UDS: Stacking tests (Omar Almaini, Seb Foucaud, Notts) ~ 1 array, 4K x 4K UDS: Stacking tests (Omar Almaini, Seb Foucaud, Notts) sub array, 2K x 2K UDS: Stacking tests (Omar Almaini, Seb Foucaud, Notts) Problems with persistence and cross-talk UDS: Stacking tests (Omar Almaini, Seb Foucaud, Notts) Point source depth map shows generally reduced sensitivity in arrays 2 & DXS: Classification (Eduardo Gonzales-Solares, CASU) Point-like Extended DXS: 2MASS cf. (Eduardo Gonzales-Solares, CASU) DXS: Mag limits (Eduardo Gonzales-Solares, CASU) Variation of K mag limits across ELAIS N1 MSBs. DXS: Spitzer gal cols (Eduardo Gonzales-Solares, CASU) Spitzer-WFCAM col-col diagram comparison with galaxy tracks. SV2 Imminent!