Homework #8

ASTR 3800

Due April 12, 2016

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Analyze the spectrum using an S statistic.

First, fit a blackbody spectrum. Find S_min. What is the best fit temperature? Is this a good model fit?

Then try a free-free bremsstrahlung spectrum (j d_nu = nu^n*exp(-h*nu/k/T) d_nu). Do this for n=2,1,0,-1 and -2. What is the best fit for n and temperature? Is this a significantly better fit than a blackbody? Is this a good model fit?

With the better fit model, estimate the range of temperatures that will include the "true" temperature, 95% of the time. To do this, create a 100x100 array of S values around S_min in the two free parameters of intensity and temperature. Make a contour plot of the two-dimensional confidence interval. The countours should be at 65%, 95% and 99.5% confidence levels. Be certain to label axes and make it look professional!