meeting 2023 12 13 n315 - JacobPilawa/TriaxSchwarzschild_wiki_5 GitHub Wiki

Context

  • Revisiting N315 now that the other projects are gradually wrapping up.

    • Here's the existing MBH measurement
    • We had still been fitting the spectra, trying to deal with bins near the center that seemed to be contaminated by the central dust disk.
    • I'll have some plots below diagnoising both the MGE fit (from Jonelle) and the current status of the spectra.

  • Some general information on N57:

    • 68.1 ± 2.5 Mpc from Jensen SBF
    • Ngroup = 14 (so not isolated at all, and this is the brightest group member with M_K = -26.3)
    • Slow rotator (lambda_e = 0.063)
    • GMOS IFU PA: 42.0 from BOX N315_PA_NOTE.txt; Mitchell IFU PA: 42.4 from BOX
    • Existing ALMA CO BH Measurement
    • 309 total bins = 249 GMOS bins, 60 Mitchell bins

Plots/Diagnositcs

MGE

  • I am taking the MGE from the existing CO BH measurement, which I assume Jonelle fit. There are actually three MGEs in that paper -- A, B1, and B2 -- where A has no dust correction, and B1/B2 have various levels of correction. Their "fiducial" result is model A, so that's what I have here.
  • One other issue I'm running into is that I don't know exactly how Jonelle went from counts in the image to her surface brightness values, so my values are offset from hers making them a bit hard to interpret (checking with Emily in the meeting...). However, we really just wanted to see what the deprojected density looked like for the MGE, ensuring that there was no central density cusp. It seems that the MGE is currently fine!
Here's a table of the MGE components themselves
  • Model A
I [Lsun/pc^2] Sig [arcsec] q PA
6280.58 0.580 0.871 0
7852.35 1.237 0.786 0
3054.92 2.347 0.704 0
3040.88 4.132 0.722 0
1039.92 8.191 0.664 0
698.232 13.25 0.748 0
121.618 26.51 0.763 0
142.889 30.90 0.689 0
69.0239 61.95 0.810 0
8.68960 192.6 0.980 0
  • Model B1
I [Lsun/pc^2] Sig [arcsec] q PA
8394.60 0.178 0.764 0
7870.46 0.617 0.716 0
7925.01 1.292 0.777 0
3040.88 2.414 0.706 0
2877.40 4.159 0.722 0
2978.52 8.211 0.663 0
1032.76 13.26 0.748 0
118.030 26.50 0.765 0
145.880 30.83 0.689 0
69.0239 61.95 0.810 0
8.68960 192.6 0.980 0
  • Model B2
I [Lsun/pc^2] Sig [arcsec] q PA
25527.01 0.178 0.764 0
8165.82 0.617 0.716 0
7780.37 1.292 0.777 0
2864.18 2.414 0.706 0
2992.26 4.159 0.722 0
1035.14 8.211 0.663 0
698.23 13.26 0.748 0
118.3 26.50 0.765 0
145.88 30.83 0.689 0
69.02 61.95 0.810 0
8.69 192.6 0.980 0
And here are deprojected density and enclosed luminosity as a function of radius.
Model A Model B1 Model B2
3d Density
Enclosed Light

Kinematics

  • First, here are some old diagnostics we had when sorting through the kinematics -- in the meeting Chung-Pei and I had last week, we decided to pause quickly on moving forward and instead ensure that I can reproduce Irina's old work on the symmetric binning scheme. However, I did some more digging on BOX and found an old set of kinematics that Irina produced with the asymmetric binning scheme. Previously, I didn't think these had been run. This should allow us to make a direct comparison between my processed kinematics and hers, which I include below.
Expand for the old sets of diagnostics, as well as some additional information on the masking procedure/dust contamination.
n = 6 diagnostics
Click to expand
Raw Point-Symmetrized
n = 8 diagnostics
Click to expand
Raw Point-Symmetrized
Comparison
Click to expand
Plot
Old Work on Masking
And here are some details and diagnostics following our masking procedure.
Full Scale
bin_maps_220418_base_Gh8Mh6_fiducial_central_mask
bin_maps_on_HST_220418_base_Gh8Mh6_fiducial_central_mask
png
Zoomed to central region
separated_zoomed
together_zoomed
together_zoomed_no_contours

Asymmetric Binning Comparsion

First, here's a one-to-one comparsion of my fits to the spectra vs. Irina's fits to the spectra and the resulting kinematics. We have excellent agreement in the vast majority of bins, with three bins in particular standing out. Note that in the figures below, I've highlighted all bins which have a >5sigma disagreement between my and Irina's values. These bins are #s 0, 19, and 21. Additionally, there were a few other bins which got flagged in higher moments, but I am less worried about these #s 163, 175.
  • Note that I am 99% sure I am using the exact same settings as Irina used (she left a note in one of the BOX folders with her settings), with the only place that I can currently see a potential difference in the masking. Specifically:
    • Wavelength range (rest): 8420-8770 A; But masking the GMOS chip gap cuts off fit at ~8750 A.
    • Template list: (15 stars from Barth et al. 2002 -- spectra are from MILES Calcium Triplet library)
    • Spectrum mask: /GMOS/galaxy_files/N315/spectra/N315_spectra_mask.fits (bright sky lines and chip gaps as assessed from inspection of GMOS spectra)
    • Initial velocity shift: 4950 km/s
    • Multiplicative polynomial: degree 3
    • Additive polynomial: degree 0 (constant offset)
    • Bias parameter: 0
Plot
Side-by-side comparison of the fits to the spectra themselves
Bin # Irina's Fit My Fit
0
19
21
163
175
I've also compared the h6 and h8 fits against one another with the same settings that Irina was using (described above) -- the agreement is really quite nice, aside from one or two bins once again. Here are those comparisons and the spectral fits.
Plot
Bin # h6 Fit h8 Fit
19
123
196

Infil Plots with my h6/h8 Kinematics

Here are some extensive diagnostics (WIHTOUT POINT SYMMETRIZATION) of the Gh8Mh6 kinematics discussed above.
Desc. h8 Figure h6 Figure
Radial Moments
Mitchell Maps
GMOS Maps
2D Surface Brightness
Bin Centers
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