AST 598 — Astronomical Instrumentation & Data Analysis — Fall 2006
Section: Astronomy with Charge Coupled Devices

Section Objectives: The aim of this section is to introduce you, the students, to the concepts and techniques that are important for near-UV–near-IR observational astronomical research that uses CCD detectors. The basic text selected for the course is Handbook of CCD Astronomy by Steve B. Howell (2nd edition, Cambridge University Press, ISBN 0521648343), supplemented with other materials discussed in class that will be provided to the students as a series of PDF documents via this web-page (and as this e-Book at the conclusion of the course). Prior to each class, students are expected to read as homework the relevant Chapter(s) of the textbook that will be covered during that class and to review the materials covered during the previous class. To prepare for the first class in this section, students should read Chapters 1 and 2 of the text book. Class Date Topics covered in this section Text book e-Book 1.   '06/09/11 Introduction to CCD's: • A Brief History of Astronomical Detectors (The Human Eye, The Photographic Plate,      The Photomultiplier Tube, Image Intensified Vacuum Tube Technology) • The Charge Coupled Device • The Bucket Brigade — a CCD read-out model [Ch. 1] [Ch. 1] 2.   '06/09/13 Introduction to CCD's (cont'd): • Gates and Voltages — CCD structure and operation • CCD's in Different Flavors • Complementary Metal Oxide Semiconductor Arrays • Superconducting Tunnel Junction Arrays • Analog to Digital Conversion [Ch. 2] [Ch. 1] 3.   '06/09/22 Characterization of CCD's: • Absorption Length, Quantum Efficiency & Charge Diffusion • Charge Transfer Efficiency & Deferred Charge • Dark Current • Bias and Overscan • Gain and Read-Noise — Janesick's method • Dynamic Range, Saturation & Linearity [Ch. 3] [Ch. 2] 4.   '06/09/25 Astronomical Signals and Noise: • Transient Effects: Cosmic Rays, Cross-talk, Persistence, Hot Pixels & Bad Columns • Distributions: Poisson vs. Gauss • Signal and Noise: The CCD Equation • Computing errors on magnitudes [Ch. 4] [Ch. 3] 5.   '06/09/27 `FITS 101': • Data Storage and Transfer • The Standard FITS Header • Multi-Extension FITS (MEF) • The ESO Hierarchical FITS Header    [Ch. 4] 6.   '06/09/29 Looking Through the Earth's Atmosphere: • Transmission, Emission & Scattering • Refraction & Dispersion • Seeing & Scintillation    [Ch. 5] 7.   '06/10/02 Photometric systems + Astronomy with CCD detectors: • Vega vs. AB magnitudes • Astronomical filter systems • Types of astronomical observations with CCDs • Aperture photometry & curve of growth • PSF fitting • Differential photometry [Ch. 5] [Ch. 6] 8.   '06/10/04 Required Calibration Data 101: • Biases • Darks • Dome flats/Pupil flats/Internal flats • Shutter shading flats • Twilight flats • Night sky flats • Orientation exposure • Focus exposures • (Spectro)Photometric standards [Ch. 5] [Ch. 7+8.1] 9.   '06/10/11 A practical example of CCD image processing from start to finish: • (Relevant portion of) Observing Log files • Starting IRAF and DS9; loading packages; selecting display buffer • Creating an inventory of the raw FITS data • Construction of bad pixel/column file • Determining the location of the virtual overscan strip • Measuring CCD read-noise and gain • Processing the bias frames    [Ch. 8.2–8.4] 10.   '06/10/13 A practical example of CCD image processing from start to finish (cont'd): • Processing the bias frames (cont'd) — Keeping a processing log in the image headers — Some IRAF and Unix/Linux intricacies — Testing the "master" bias image • Processing the dark frames — Do we detect the bulk dark rate? — Warm/hot pixel mapping using mask images    [Ch. 8.5] 11.   '06/11/08 A practical example of CCD image processing from start to finish (cont'd): • Processing the dome- and twilight-flats — Constructing pixel-to-pixel response frames per filter — Constructing illumination pattern frames per filter • Deriving the shutter shading pattern; evaluating its significance • Processing the science target images — Inspection, Adding filter keyword, Conversion to 32bpp — Correction for structure in the bias — Subtraction of the instantaneous bias level (overscan level) — Testing whether dark- and shutter shading corrections are needed — Correction for small-scale sensitivity variations — Correction for large-scale illumination variations   [Ch. 8.6] 12.   '06/11/17 A practical example of CCD image processing from start to finish (cont'd): • Photometric calibration using standard stars — Aperture photometry on standard star images — Solving the photometric calibration equations • Photometric analysis of astronomical sources — Differential photometry of SN 2005bk [Ch. 6] [Ch. 8.7] 13.   '06/11/20 A practical example of CCD Spectroscopic data reduction: • (Additional) Calibration data to be acquired — Example of a HeNeAr comparison lamp spectrum • Processing the calibration frames • Processing the science target and comparison lamp frames [Ch. 6] [Ch. 9] Last update: Jan 12 2007 [RAJ]