meeting 2025 05 05 n57 - JacobPilawa/TriaxSchwarzschild_wiki_5 GitHub Wiki

Context

  • Gathering some infomration on the new galaxies so we can make a plan from here on out. In June of last year/a bit in December, we started to look at the kinematics for (we were still fitting MGEs/verifying the kinematics so we hadn't made it too far):

    • I'll need to refit the spectra in the cases below but that should be quite quick. When fitting these, I had switched from using indices to select the Barth stars to their file names, so the templates seem to have actually been correct. However, the ppxf code I was using at the time had the bias still set to 0.0, and I had been explicitly setting the additive polynomial to be degree 0. I'll play around with this to obtain some diagnostics.
    • Last week, I came across this paper which could be relevant for us. I skimmed this, but the essentially apply some selection criteria to archival IFU surveys to determine the "most likely" galaxies with black hole binaries. Among their top 10 are a few of the galaxies below (NGC410, NGC1060, NGC4874) which we could think about prioritizing.

  • NGC410

    • Seems like we eventually tracked down all the data for this galaxy and progressed furthest here.

  • NGC545/547

    • We had also progresssed quite a bit on these two galaxies, fitting both sets of kinematics which were in decent agreement with Irina's measurements. The diagnositcs for N545 are here, and the diagnostics for N547 are here but look to be a bit less complete.
    • The big challenge here I was facing (hadn't worked on it too long) was fitting the MGE in a nice way since N545/547 are a close pair.

  • NGC777

    • Similar story to the other galaxies above -- I had made some nice progress fitting the kinematics here which were in decent agreement with what Irina had found, and I had been trying to get MGE fits to be decent.

  • NGC4874

    • Again, similar story to what was above -- had started some kinematic fitting and seemed to have been struggling getting reasonable MGE fits. Here's that page.
New Galaxies

In the email from yesterday, Chung-Pei had mentioned adding the following galaxies to our list:

  • NGC1060
    • Folder exists on BOX, but I think we'll need to get the full set of spectra from Emily.
  • NGC2258
    • Folder exists on BOX, but we'll need to get the spectra.
  • NGC2274
    • It seems like the spectra for N2274 are on BOX, so we can get started on these ASAP.

Diagnostics

  • For the galaxies above for which we have data, I quickly ran them through pPXF ensuring that the settings are up-to-speed with our latest settings. Specifically, these use:

    • Barth Stars
    • Starting guess for (V, sigma) = (0, 200) km/s
    • All cases use an additive polynomial of degree 0, multiplicative of degree 3
    • Bias = 0.2
    • Masks all straight from BOX
    • N_{MC} = 100

  • The fits here are looking really great. I've been going through all of them individually and there are a few I need to look at a bit closer. Here's a quick comparison of the RMS vs. spectrum number for the galaxies I've refit this morning

Galaxy Diag. Plot
N410
N545
N547
N777
N2274
N4874
  • And here's diagnostics showing the fiducial spectra fit, histograms of the residuals, and the kinematics from the 100 MC iterations. These are what I'm currently looking through and will spot check these kinematics. I mostly want to experiement with the additive and multiplicative polynomials in these cases, and will add the polynomials to these diagnositc plots. They take a few minutes to load since they're quite large images:
NGC410
Plot
NGC545
Plot
NGC547
Plot
NGC777
Plot
NGC2274
Plot
NGC4874
Plot
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