2022-03-09

are data-driven approaches to RV measurement biased?

Matt Daunt (NYU) is re-building our wobble code for measuring stellar radial velocities without any stellar or tellurics model. He is finding that it is slightly biased towards smaller radial velocity amplitudes than what we inject into fake data. This also mirrors things that Bedell (Flatiron) and I have seen in various experiments. I think there is something going on with spectral edges: At the edge of the observed spectral domain, some observations have lines shifted into and out of the observations. The mean spectrum obtained from those measurements isn't necessarily capturing all of this fairly. Or at least it has to be handled carefully. Are we doing this right? Experiments we have suggest that we don't have this quite right yet.

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