Monday, June 6, 2011

M dwarf velocity code automated!

So I fixed my if/else statements, debugged here and there, and my code is now automated!

The program takes selected M dwarfs from Andrew's DR7 file, pulls the corresponding spectra from SDSS, matches it up with the appropriate template (based on spectral type), and calculates the shifts in spectra. This means that using this program, you can choose any set of M dwarfs from Andrew's DR7 file, and calculate their radial velocities (and compare them to the catalogued radial velocities).

So now that I've done this for individual M dwarfs, we can apply this same process to analyzing M dwarf and white dwarf binaries. Because the WD will take up the bluer end of the spectrum, I've written the code so that the velocity shifts are calculated using only the redder end of the spectrum (between 7200-8800 Angstroms), so as not to interfere with the WD.

Because there are multiple exposures from SDSS data, for close WD-Md pairs (which are moving very fast), we can calculate the velocity from the changes between exposures.

Tomorrow, I will focus on reading in the spectrum of a single WD-Md pair, and doing a similar process for the binary pair, then once that looks good, automating it. Andrew pointed out that I have to be careful as there is cosmic ray interference with some of the spectra I will be using. (It sounds really cool, but will be kind of a pain to deal with).

We had our first group meeting this afternoon -- It was great hearing about what everyone is working on.

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