meeting 2024 06 03 n777 - JacobPilawa/TriaxSchwarzschild_wiki

N777

Kinematics from MASSIVE XIII:

Plot
images/n777.png

High Level Information

Stats:
- D = 68.0 ± 2.6, Jensen+21 SBF
- Brightest group member, 7 group members
- _e = 291 km/s
- Mk = -25.94, log10(Mstar) = 11.87
- eps = 0.17, lambda = 0.05 (Slow rotator)
- log10(Mhalo) = 13.5
- MASSIVE XIV: Note that MASSIVE XIV says this galaxy is aligned, whereas MASSIVE X says it is misaligned
  - PA GMOS = 311 +/- 22
  - PA Mitchell = 8 +/- 10
  - PA Phot = 148.6 ± 0.8
  - Psi GMOS = 18.1 ± 21.5 (MASSIVE XIV)
  - Psi Mitchell = 39.6 (MASSIVE X)
- Photometry:
  - has slightly increasing ellipticity with radius; the other parameters are all nearly constant.
Recent paper from O'Sullivan which could be interesting!
GMOS:
- All files seem to be on BOX.
- Has both symmetric and non-symmetric binning schemes.
- Other details:
  - Files on BOX say:
    - +X = 148 deg. E of N. in orbit modeling files
    - +X = +X = -32 deg. E of N. in paperversion figures of kinematic moments
  - PSF listed as: avg. FWHM = 0.39" (Gaussian)
  - 128 bins (symmetric)
  - 131 bins (non-symmetric)
Mitchell
- All Mitchell files for all galaxies are present! There are folded and unfolded versions for everything. I'm currently sticking with our usual unfolded data.
- 64 bins (unfolded)

Kinematics

Reproducing Irina's Results

First, I started by reproducing Irina's results:
- Symmetric binning scheme with the associated spectra located here: /Users/jacobpilawa/Research/N777/N0777/N777_spectra_20160603_voronoi_symmetric/
- Using the mask on BOX which has a different file name than the one listed by Irina below (doesn't seem to exist).
- Table 2 of Barth+02 for the template stars.
- Uncertainties are computed with 100 MC iterations.
Irina lists the settings on BOX as:

Nominal settings for pPXF fits to NGC 777 GMOS data
---------------------------------------------------

Wavelength range (rest):  8420-8730 A

Template list:  barthlist.txt
(15 stars from Barth et al. 2002 -- spectra are from MILES Calcium Triplet library)

Spectrum mask:  /GMOS/galaxy_files/N777/spectra/N777_spectra_mask1_nochipgap.fits
(bright sky lines as assessed from inspection of GMOS spectra)
(GMOS chip gap lies outside the pPXF wavelength range)

Initial velocity shift: 5000 km/s

Multiplicative polynomial: degree 3

Additive polynomial: degree 0  (constant offset)

Bias parameter: 0

With these settings, I can get quite close to Irina's exact results. Here are some diagnostics from this reproduction.
- Note that the kinematics here are not point-symmetrized.
- These also use the symmetric binning scheme (whereas we'll likely use the non-symmetric binning scheme for the actual modeling), but I wanted to make sure I was able to reproduce her values.

Bin Centers	Radial Moments	GMOS Maps	Mitchell Maps	Kinematic Comparison

And the spectra and resulting fits look beautiful!

Plot

Extending to h8 with symmetric binning

Given that I can reproduce Irina's results more or less by fitting out to h6, I wanted to see how things change when fitting out to h8, so here are those diagnostics and comparisons to Irina.
Note the settings from above are exactly the same; the only different is the cutoff of the GH series.

Radial Moments	GMOS Maps	Mitchell Maps	Kinematic Comparison

Spectral fits out to h8

Plot

Extending to h8 with non-symmetric binning

And lastly, here's what we'll likely use for the modeling. Note that this uses the non-symmetric binning scheme (so it's hard to compare directly to Irina's which is symmetrically binned).