imaging spectroscopy

Schiminovich and I met at an undisclosed location to discuss ongoing projects, and he showed me materials from the first-light run of a prototype imaging spectrograph his team has built and deployed at MDM. We discussed a bit how one ought to calibrate such a spectrograph, and reduce the data. My loyal reader will not be surprised to learn that I advocate a causally and probabilistically justified generative (or forward) model that goes from the intensity field incident on the telescope down to the imager pixels in the focal plane. We discussed a bit about how to build that model, which ought to be informed by instrument modeling, calibration data, and science data. We also discussed how to take the science data to make them most useful for calibration. I volunteered (yes, I know) to consult on the data analysis. Weren't we supposed to be working on something related to GALEX?

Oh yeah, we are, and on that front Schiminovich showed me his "bespoke" data reductions for GALEX imaging of the Magellanic Clouds. The coolest thing about them is that you can see the difference—even in a single band—between the very young and slightly older star-forming regions: In the youngest regions, the light is "noisier" because the shot-noise is higher (there is more disparity in stellar luminosities, or fewer effective stars per unit brightness). This suggests a "surface-brightness-fluctuations" approach to age dating! That would be fun.

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