AST3722C Quiz on Detectors, CCDs, and CCD Imaging

1) Which regions of the spectrum (gamma, X-ray, UV, visible, IR, radio) 
are generally useful to astronomers observing normal stars? 

2) Define Detective Quantum Efficiency.  How is this different 
from Quantum Efficiency?

3) List noise sources could be considered in determining 
signal-to-noise ratio.  Which of these are independant of 
the portion of the sky and object being observed?

4) Why have CCDs replaced the photomultiplier for most 
astronomical photometry?

5) What are the most important features of CCDs that lead 
to their replacing photographic emulsions in astronomy.  
Which of these is the most important?

6) What considerations must be kept in mind concerning 
taking of CCD darks?  Why take more than one dark?

7) What is the difference between averaging and median 
combining?

8) In general, reduction of images taken with the 
0.46m scope at RHO does not include subtraction of bias frames.
(a) why not? 
(b) under what circumstances does bias 
frame subtraction become potentially important? 
(c) How might one get a bias frame with the CCD on the 0.46m scope?