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Observing Condition Constraints
Example 1 : NIRI Spectroscopy of an Extended Object

This is an example of aspects to consider when choosing observing condition constraints. The science drivers for each program are distinct, of course, and thus the appropriate set of conditions for your own observations may be quite different. The example is taken from the NIRI System Verification plan (program 7).

Consider a program to take an H-band (1.7µm) spectrum across the star-forming core of the galaxy M82 to measure the relative H and He recombination line strengths. Good spectral resolution is required, both to separate the Brackett-series H lines and to achieve good line-to-continuum contrast against the underlying stellar emission. NIRI in its f/14 configuration was selected as spectral resolution is more important than slit throughput for this program.

caution Note that the statistical likelihood of execution of this observation, if all of the observing conditions are truly uncorrelated, is 100% * 50% * 100% * 80% = 40% of the time when the target is accessible in the sky. (In fact we expect some mild correlation and so this is a slight underestimate). Note that 40% is not the probability of my observations being completed successfully in the queue since a project will be allocated time when conditions are right for that project.

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Last update March 01, 2007; R. Mason. Original page by P. Puxley.