meeting 2025 08 12 n410 - JacobPilawa/TriaxSchwarzschild_wiki

Context

Moving along with N410 now that we have N57 mostly sorted out. I'm continuing here with some additional spectra tests that we've run for N57 to verify that N410 behaves similarly.

Takeaways

Extending to h8
- Extending the N410 data out to h8 (with the Barth library) seems to behave extremely reasonably. Note that I ran this on both the symmetric and asymmetric cases for the spectra, and they both appear to be at the same level of agremeent (or so).
- One question is if we want to continue on with the asymmetric binning scheme. This is what we've been doing with the other recent galaxies, but there's really no reason to prefer one or the other. I suppose that sticking with asymmetric binning to be consistent with the other recent galaxies makes the most sense.
Library testing
- The library tests are behaving a bit differently than we saw with N57 and N315. For those galaxies, we were able to get quite nice agreement via the superspectrum test and the Barth results alone, in particular after removing any of the strange templates that were picked up by the superspectrum fit.
Polynomials:
- Multiplicative Degree: it seems like this multiplicative degree again needs to be something like at least 2 or above for the results to be reasonable. In many of the bins, there is hardly any variation beyond mdeg=3 (for adeg=0).
- Additive degree: I'm seeing a similar trend that we saw with the other galaxies for N410, where adeg=-1 gives elevated sigma values relative to the other adegrees. If we continue to increase adeg from adeg=0 to adeg=4 or so, the results are somewhat robust (there is a bit of variation here), but nothing too extreme I think.
- At least from what I'm seeing, without anthing "better" to go off of, I think fixing adeg=0 should be alright for N410, too. It seems like no matter which polynomial order we are to pick, we are going to have some disagreement for a subset of the bins, so I don't think there will be a perfect solution here.
Sigma Clipping:
- The sigma clipping (for reasonable sigma = 2.0, 3.0) seem to have very little effect on the resulting kinematics compared to our fiducial case. In particular, from a quick glance, it seems like the spectra are of high enough quality that the sigma=3.0 case is hardly picking up new areas to mask. Even if we go with the a more conservative sigma=2.0, the kinematics are still in very nice agreement with the "base" set of kinematics.
Bias:
- The bias similarly has essentially 0 effect on the kinematics. Note that I'm using the base settings (adeg=0, mdeg=3, Barth templates, etc)., and bias=0.0 and bias=0.2 are essentially exactly the same.

Extending to h8

Note that up to now, I had been fitting out to h6 to check agreement with Irina. I seem to be able to reproduce her fiducial results, so extending to h8 now seems to make sense. Also note that the results below are using the symmetric binning scheme (again, so we can compare to Irina), but we have generally shifted to the asymmetric binning in the past, so we'll likely want to do that too at some point (maybe...?).
So these results are comparing our fiducial set of fits (symmetric binning out to h6) compared to some of the higher order results. These all use the Barth library ONLY.

Case	h6 vs h8	h6 vs h10	h6 vs h12
One-to-One
Differences

And here's a comparison of the additive polynomial distributions:

Case	h6 vs h8	h8 vs h10	h8 vs h12

And the fit qualities for these cases:

h6	h8	h10	h12

One interesting thing to note -- it looks like scan603.fits is once again being selected from the Barth subset as being extremely important to the fit. Here are the Barth templates and their weight for the fiducial fit

Summed	By Bin

Various Library Tests

One thing I wanted to test was the sensitivity of the kinematics to various template choices, just like we did for N57. I just want another example galaxy here that we can try to make sense of with the various template choices.

Barth vs. Full CaT	Barth vs. Trimmed 209	Barth vs. Trimmed 384 + 3	Barth vs. FGK

Superspectrum Testing

I then proceeded with the superspectrum testing that we did for N57 -- I started with the library of 384 + 3 missing Barth templates, fit the superspectrum of N410, extracted the non-zero weights, and trimmed away the strange looking templates that were picked out.
Takeaways:
- In the initial superspectrum test, there are once again 11 templates that are given non-zero weight, with two of the templates being "weird looking", with one looking like a B star (scan374.fits) and the other looking like an M star (scan387.fits).

Initial Superspec Fit	Top Templates

And now comparisons of the fiducial Barth h8 fits vs. the fits using the 11/11 and 9/11 superspectra results:
- Seems like I'm getting slightly different behavior here than we saw with N57;

Barth h8 vs. 11/11 Superspec	Barth h8 vs. 9/11 Superspec

Asymmetric Binning

Given how some of the results are turning out above, I wanted to turn toward the "asymmetrically binned" spectra to see if we are seeing the same behavior in the kinematics.

Extending to h8

Case	h6 vs h8	h6 vs h10	h6 vs h12
One-to-One
Differences

Superspectrum Testing

Similarly to above, I constructued the superspectrum from the asymmetrically binned spectra, fit the superspectrum with the 387 set of templates, and then compared the fiducial h8 Barth to the resulting kinematics:
- Notably, the same exact set of templates get picked (11) as we had in the symmetrically binned case, including the same two "weird" spectra:

Initial Superspec Fit	Top Templates

And now comparisons of the fiducial Barth h8 fits vs. the fits using the 11/11 and 9/11 superspectra results:
- Seems like I'm getting slightly different behavior here than we saw with N57;

Barth h8 vs. 11/11 Superspec	Barth h8 vs. 9/11 Superspec

Additional Small Items/Some Reminders of Some Past Tests

Effect of the Bias

One of the things we have consistently wanted to look at is the effect of switching the bias from bias=0.2 to bias=0.0. In the past, I have seen essentially no effect of the bias for both N315 and N57, and it'd be nice to confirm that this holds for N410 as well.
The plots here show the fiducial set of kinematics with both bias = 0.2 (default) and bias = 0.0, and there is virtually no difference in the kinematics for N410:

Fiducial vs. Bias = 0.0

Sigma Clipping

Note that the y-axes labels here are remnants from creating some of the other plots on the page. The cases here use identical fiducial settings, the only thing being changed is whether or not I'm sigma clipping.
It appears like the sigma clipping has little impact on the kinematics.