Astronomy 2:
Observational Astrophysics-- the old course
  Dr G. Woan 
10 lectures starting  10 October 2001, ending 5 December 2001

  This course is designed to follow on from the A1 course and introduces many of the most important astronomical techniques and instruments in use today.  It will concentrate on those factors that drive the design of telescopes, such as sensitivity and resolving power, and give concrete examples of their use in observational astrophysics at optical and radio wavelengths

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Course details
Copies of lecture notes will appear here as the course proceeds. They are for reference only, and should not be used to replace your own lecture notes. You will find the course much harder if you don't create your own written version, so please do not print these notes out in quantity.

Ideas of radiant energy
The units and concepts of received energy: luminosity, radiant flux and flux density; solid angle; specific intensity and surface brightness; temperature and effective temperature; apparent and absolute magnitude; bolometric and colour magnitudes; distance modulus; bolometric correction.
lecture notes:  1 2 3 4 5 6 7 8 9 10 11 12
Pictures: [Planck  spectrum]
Handouts:[ Quick facts sheet #1]

Detectors and telescopes
Simple telescope optics; image intensity and illumination; telescopes at different wavelengths, from gamma rays to radio waves; bolometers and radio detectors.
lecture notes:  1 2 3 4 5 6 7 8 9
Pictures: [ Cherenkov detector | Chandra X-ray satellite | HST | ISO | Lovell telescope ]
Handouts:[ electromagnetic spectrum ]

 Examples of optical detectors
[Photographic plates, characteristic curves and microdensitometers;] -- not examined
photomultipliers; microchannel image intensifiers;  charge-coupled devices.
lecture notes:  1 2 3 4 5 6 7 8 9 10
Pictures: [ Automatic Plate Measuring machine ]
Handouts:[ Quick facts #2 | CCD clocking procedure ]
Sloan Digital Sky Survey

Ideas of sensitivity
Signal-to-noise ratio; noise and bandwidth as the limits of sensitivity; Poisson noise; background and dark current noise in CCDs; quantum efficiencies of photon detectors; relation of these ideas to radio noise; detection of continuum and line sources.
lecture notes:  1 2 3 4 5 6 7 8 9 10
Pictures: [  Hubble deep field   ]
Handouts:[  Quick facts #3 ]
Hubble Wide Field Planetary Camera II Handbook

The atmosphere
Absorption/transmission windows; optical depth and zenith extinction; Bouguet’s Law; scattering, including Rayleigh scattering; refraction; optical scintillation; interplanetary and interstellar scintillation.
lecture notes:  1 2 3 4 5 6 7 8 9 10 11
Pictures: [  ]
Handouts:[  ]

Spectral techniques
The importance of spectroscopy in astrophysics; dye and interference filters; prisms; Fraunhofer diffraction and diffraction gratings; principles underlying spectral resolving power; design of a slit spectrometer.
lecture notes:  1 2 3 4 5 6 7 8 9
Pictures: [ Optiks (Newton, 1704)]
Handouts:[ Grating responses ]

Resolving power and  interferometry
diffraction and the lambda/D relation;  fringes;  the problem of ‘seeing’;  speckle patterns and speckle interferometry; the Michelson stelar interferometer and its foundations in optics theory;  stellar diameters and double sources.
lecture notes:  1 2 3 4 5 6 7 8 9 10 11 12
Pictures: [ COAST | Capella resolved ]
Handouts:[  ]

Radio interferometry (if there is time)
Extension of interferometry ideas to radio waves; fringe visibility as a measure of source structure;  the fringe visibility - correlation relationship; radio correlators; very long baseline interferometry and the need for good clocks.

Handouts and Quick Facts Sheets
Clean copies of the following handouts are available from the astronomy secretary's office (room 608) as they appear in the course.

Quick facts sheets

  1. Ideas of radiant energy
  2. Optical detectors
  3. Poisson noise
Other handouts
The recommended textbook for A2 is An Introduction to Modern Astrophysics, B W Carroll and D A Ostlie, Addison Wesley .  You will also find information in the following books relevant to Observational Astrophysics: