# Rotate-and-tilt wrapper potential¶

class galpy.potential.RotateAndTiltWrapperPotential(amp=1.0, inclination=None, galaxy_pa=None, sky_pa=None, zvec=None, offset=None, pot=None, ro=None, vo=None)[source]

Potential wrapper that allows a potential to be rotated in 3D according to three orientation angles. These angles can either be specified using:

• A rotation around the original z-axis (galaxy_pa) and the new direction of the z-axis (zvec) or
• A rotation around the original z-axis (galaxy_pa), the inclination, and a rotation around the new z axis (sky_pa).

The second option allows one to specify the inclination and sky position angle (measured from North) in the usual manner in extragalactic observations. A final offset option allows one to apply a static offset in Cartesian coordinate space to be applied to the potential following the rotation and tilt.

__init__(amp=1.0, inclination=None, galaxy_pa=None, sky_pa=None, zvec=None, offset=None, pot=None, ro=None, vo=None)[source]

NAME:

__init__

PURPOSE:

initialize a RotateAndTiltWrapper Potential

INPUT:

amp= (1.) overall amplitude to apply to the potential

pot= Potential instance or list thereof for the potential to rotate and tilt

Orientation angles as

galaxy_pa= rotation angle of the original potential around the original z axis (can be a Quantity)

and either

1. zvec= 3D vector specifying the direction of the rotated z axis

2. inclination= usual inclination angle (with the line-of-sight being the z axis)

sky_pa= rotation angle around the inclined z axis (usual sky position angle measured from North)

offset= optional static offset in Cartesian coordinates (can be a Quantity)

OUTPUT:

(none)

HISTORY:

2021-03-29 - Started - Mackereth (UofT)

2021-04-18 - Added inclination, sky_pa, galaxy_pa setup - Bovy (UofT)

2022-03-14 - added offset kwarg - Mackereth (UofT)