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AFD-Illinois / ipole

Polarized covariant radiative transport code
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WIP: Better fitting functions for rhoV #15

Closed bprather closed 4 years ago

bprather commented 5 years ago

Most description is in the commit. Switch to bona fide Bessel functions when the fits get bad, at low temperatures (Theta_e < 3) routinely reached in the outer disk. Defensively added a switch at even lower temperature to use the static zero-temperature limit, though I have no evidence that disk electron temperatures ever get that low.

Note (or test for yourself) that this branch is no slower than dev (though both remain a 10-15% slower than master, probably due to some missed inlining due to the re-org).

Finally note that much of this rotation may be spurious from a physical standpoint, as the outer areas of the GRMHD simulation may be anomalously cool/dense.

bprather commented 4 years ago

The reasoning behind this PR & the cuts chosen should be visible in the below plot comparing several fits of rhoV. "ipole" denotes the fits used in ipole previously, approximating the relevant Bessel functions. "Bessel" and "Dexter" use the full Bessel functions. "Scherbakov" is the original fit on which "Dexter" & "ipole" are based, and the "Limit" is the low-temperature limiting behavior of Faraday rotation.

rhoV_approx