Thursday, June 18, 2009

Two down, plenty left to go...

About to finish up item 3 of the Plan.
The past few days I've just been going through and documenting my star-picking process and kind of taking inventory of my really good graphics and adjusting them for updated parameters. My official classification cut-off is now 0.75-1.0 for stars.

Today I have been working on the flux-ratios. My hope is that two peaks will appear on my histogram and help me pick a parameter to further weed out a few galaxies (which would correspond to the anomalous lines, that don't fit a star's profile, on my aperture magnitude vs aperture radius plots). When I went through, I was careful with my math in my code, making sure I had done my distance modulus algebra correctly and all, and made some good histograms.
somewhere down the line I realized I'd in fact still managed to input my magnitudes backwards. I had the equations set up correctly, but instead of solving for flux(ap11)/flux(ap8) I had gotten flux(ap8)/flux(ap11). Not a huge deal, so I just flipped 'em around to see where that got me.

What's left to do is really look at their peaks (i.e. I've been looking at them, but am unsure what to do with what I see, and need to consult Beth in the morning, and compare "star" vs "galaxy" peaks, etc.), and pick a parameter, like flux ratios greater than 1 are in fact galaxies and discard those from my star catalog.
Then: vacation, and then moving on with the Plan.

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