2020 10 08

Meeting Oct 8, 2020

Recap

Read & Discuss:

• AGAMA

• A Self-consistent Field Method for Galactic Dynamics

• Basis function expansions for galactic dynamics: Spherical versus cylindrical coordinates

• Start making data loaders.

Meeting Notes

AGAMA

How does the CylSP represent non-axisymmetry when it only has one expansion term?

How does the terms in spherical harmonic expansion relate to the terms in CylSP? This is for the spline method.

How do they relate to the full expansion method (SCF)? For disks? Zhao 1996; Lilley et al. 2018 Kalnajs 1976

Future thoughts:

• How do the errors propagate into Action-Angle calcs?

• Instead of using an orthogonal family motivated by theory, instead use the modes from the covariance matrix (or the fisher matrix).

  • This is maybe the second paper!

For next week

• Start making data loaders. In a PR [@nstarman]

• Binney and Tremaine sections 2.6-3

  • Focusing on how the cylindrical expansion can represent non-axisymmetry with only one term

• Jo's notes

  • Focusing on how the cylindrical expansion can represent non-axisymmetry with only one term

• Notebooks

  • Make some standard component DFs / density [@CCAstro35]

    • Disk
    • Bar
    • Disk + Bar
    • Disk + Spiral
    • Disk + Bar + Spiral
    • Halo

  • Expand them with the Cylindrical and Spherical methods in AGAMA [@nstarman]

  • For Bar + Disk models expand with best technique for each, respectively

For two weeks

• Full Expansions for Disks
  • Kalnajs 1976