AST460: Assignment 7
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(Oct 26 2012)
1. Finalize your SRT spectrum in terms of velocity information,
baseline fitting etc. Using lds_spectra.ps provided on the class web site
compare your spectrum with the spectrum obtained at the same location in the LDS
survey. Especially check if your spectrum is covering the whole velocity range
of HI emission at the positive velocity end of the spectrum.
Let me know if there are problems and we can take more observations
if needed.
2. Following the description in the Project Introduction document,
find and measure the radial velocity of the tangent point in your SRT spectrum.
You also need to estimate the uncertainty for your radial velocity measurement.
Please comment and discuss any problems you have encountered during data reduction which
could have introduced any systematic issues regarding the quality of your
measurements.
3. Calculate the Galactocentric distance, R, and the orbital velocity, V,
for your tangent point using the Galactic constants given in the
Project Introduction document. Send me your results and I will distribute
all class results by e-mail.
4. Using all class results, plot the Galactic rotation curve (overplot
uncertainties). Compare the resultant curve with the curve provided in class notes,
are we close enough? Comment on any differences.
5. Using the orbital velocity of largest sampled Galactocentric radius,
estimate the total mass of the Milky Way (both visible and dark) enclosed
within this radius.
The assignment is due on Nov 9.