We have decided to analyze the accretion onto a neutron star just up until the hydrogen burning begins. We'll first attempt this as an adaptation to the Bondi accretion problem with a solid sphere near the origin (also relevant to the problem of infall onto the proto-neutron star during core collapse). If we're successful, we'll try an accretion disk in 2D with polar geometry.

• Input Person (Sarah Schwartz)
  • [ ] Looking up accretion rates for
    • [ ] X-ray bursts
    • [ ] Novae
  • [ ] Density of in falling material
  • [ ] Masses of objects
  • [ ] Alpha parameter
• Code Person (Justin Brown)
  • 2D
    • [X] Get the VH-1 polar model working.
      • Set ngeomx = 1 (radial cylindrical), ngeomy = 3 (theta), nlefty = 3, nrighty = 3 (periodic)
    • [X] Set up accretion
      • Set nrightx = 2 (constant inflow), uotflo * rotflo * outer area of simulation (2 * pi * xmas) = 1
      • Set votflo to be the desired velocity at the boundary edge
    • [X] Implement gravity
      • In forces, set grav (n) under sweep “x”, cylindrical to be -GM/xao(n)**2
    • [X] Implement a viscosity model.
      • We're choosing to use the derivative in the radial direction of only the tangential coordinate
        • alpha*1/r(dv/dr)+alpha*d2v/dr2
      • In forces, set grav (n) under sweep “y” to the above expression
• Analysis Person (Amber Lauer)
  • [x] Get visualization working
    • [x] Install NetCDF
      • visit on ubuntu/linux was a quagmire, went with windows virtualbox installation :(
  • [x] Gathering the initial conditions for novae and X-ray bursts
    • have average values for NS and WD, time permitting will constrain to single case and derive from scratch
  • [ ] Determine the input abundances
  • [ ] Build the nuclear network for the problem
  • [ ] Take output from the codes
    • [ ]determine when hydrogen burning begins
    • [ ]analyze data values to optimize scale(linear vs log) and ranges(0-?) for visualization

Link to Code on GitHub: External Link