MegaPrime/MegaCam Home CFHT Home General Information Instrument Description Press Release April 8, 2003 Publications Acknowledgment Text Specifications & Performance Quick Performance Summary General Summary Technical Considerations Off-field bright stars immunity Shutter ballistics Baffling & pinhole mask On-sky Instrument History Observing Runs Observing Statistics Observing Statistics II Upgrades & Problems Zeropoint History New Observing Process Exposure Time Calculator Mapping Stars & Pointings Queued Service Observing QSO PH2 SkyProbe Data Preprocessing & Calibration Elixir System Information Raw Data Description CFHT Data Preprocessing CFHT Data Calibration CFHT MetaData Products Raw & Elixir FITS headers Elixir Releases History Elixir Real-Time Elixir RT Field Guide Elixir RT Status Flat-Fields Status Standards Status Instrument Operations Cooling Status Cryostat Status External Related Sites Data Archiving at CADC Data Processing at Terapix Contacts Support Astronomer

MegaPrime/MegaCam - Quick Performance Summary (the basics to prepare a time proposal) Starting with semester 2015A, Megacam "ears", consisting of four additional CCDs on the side of the focal plane, are being used, to take advantage of the larger, new set of broad and narrow band filters acquired late 2014. The old broad band filters are now renamed with a trailing S: uS,gS,rS,iS,zS, while the new broad band filters are simply named u,g,r,i,z. The reference photometric magnitudes are the AB magnitude in the old (S) filters (SNLS magnitudes). The old CFH12K narrow band filters are not offered anymore. Sky background values and airmass terms for the new filters will be updated as statistics become available. Geometry Number of detectors 40 Detector size (pixel) 2048 x 4612 Pixel scale @ center of the field (arcsec / pixel) 0.187 Camera field of view 0.96 deg x 0.94 deg Image quality degradation from center to edges ~0.05 arcsec Median seeing at center (reduced 2003A sample) gS: 0.77 arcsec, iS: 0.66 arcsec Photometry Magnitude system AB Filters uS, gS, rS, iS, zS, u, g, r, i, z Zero points (e- / sec) at 1 airmass 25.74, 27.00, 26.50, 26.38, 25.34, 25.78, 27.11, 26.74, 26.22, 25.02 Airmass term 0.350, 0.150, 0.100, 0.040, 0.030, 0.350, 0.150, 0.100, 0.040, 0.030 Color term (SNLS system) 0.000, 0.000, 0.000, 0.000, 0.000, -.232, -.087, +.065, +.068, +.065 Color (Instrumental to SNLS) (SNLS mag.) xx-xx, xx-xx, xx-xx, xx-xx, xx-xx, uS-gS , gS-rS , gS-rS , rS-iS , iS-zS Dark sky brightness @ zenith - Moon 0% 22.70, 22.00, 21.30, 20.30, 19.40, 22.70, 22.00, 21.30, 20.30, 19.40 (mag / arcsec^2) Grey sky brightness @ zenith - Moon 30% 21.20, 21.30, 20.80, 20.30, 19.40, 21.20, 21.30, 20.80, 20.30, 19.40 (mag / arcsec^2) Bright sky brightness @ zenith - Moon 60% 19.70, 20.50, 20.40, 20.30, 19.40, 19.70, 20.50, 20.40, 20.30, 19.40 (mag / arcsec^2) Point source MagAB SNR=10 Dark 1hr 0.8" 25.30, 25.70, 25.10, 24.70, 23.70, 25.60, 26.00, 25.50, 24.60, 23.40 Point source MagAB SNR=10 Grey 1hr 0.8" 24.70, 25.30, 24.90, 24.70, 23.70, 24.80, 25.70, 25.20, 24.60, 23.40 Field galaxy MagAB SNR=10 Dark 1hr 0.8" 25.00, 25.20, 24.60, 24.30, 23.20, 25.10, 25.60, 25.00, 24.20, 23.00 Field galaxy MagAB SNR=10 Grey 1hr 0.8" 24.30, 24.90, 24.40, 24.30, 23.20, 24.30, 25.20, 24.80, 24.20, 23.00 Transition from AB to Vega magnitude system -.346, +.092, -.171, -.401, -.554, -.621, +.087, -.181, -.392, -.526 (mag) New narrow band filters (same FOV) Halpha, HalphaOFF, OIII, OIIIOFF, CaH&K Camera Exposure overhead ~40 seconds Read noise ~3 ADU Digital range 65536 ADU Raw fringe amplitude ~6% in i/iS, ~15% in z/zS Observing Typical exposure time (second) 300 Minimum exposure time (second) 1 Filter exchange time (second) 90 Observing mode Exclusively Queued Service Observing (QSO) Data pre-processing Elixir at CFHT