Point_mass_location

[kufapetr]

We try to determine the location of an external point mass as a significant source of gravitation (SMBH). According to our configuration, it is located outside the 2D grid domain. However, we found that the correct command in input file is (example coordinates): castro.point_mass_coord = -1.86e15 3.e14. This does not work, Castro ignores it. Do you have an idea about the correct input command?

[maximumcats]

We don't have the functionality right now to place the point mass at an arbitrary location like this, but it would be straightforward for us to add.

[kufapetr]

Thanks, Max, so what should I do about this?

[maximumcats]

Until we can adjust this, your option would be to align your domain so that you can use the existing option, which only allows an offset for the point mass in the vertical direction. Copying the below from _cpp_parameters:

#
# The shift is applied along the vertical direction:
#   1D: x-direction
#   2D: y-direction
#   3D: z-direction
point_mass_offset_is_true    bool           0                  GRAVITY

# Distance of the point mass shifted from the problem center.
# This is to use in conjunction with point_mass_offset_is_true.
point_mass_location_offset   Real          0.0                GRAVITY

[kufapetr]

Thanks, I understand now.