# mypy: disable-error-code="operator,dict-item"
from typing import Optional, Union, Annotated
from caskade import forward, Param
from .base import ThinLens, CosmologyType, NameType, ZType
from . import func
from ..backend_obj import ArrayLike
__all__ = ("SIS",)
[docs]
class SIS(ThinLens):
"""
A class representing the Singular Isothermal Sphere (SIS) model.
This model inherits from the base `ThinLens` class.
Attributes
----------
name: str
The name of the SIS lens.
cosmology: Cosmology
An instance of the Cosmology class.
z_l: Optional[Union[ArrayLike, float]]
The lens redshift.
*Unit: unitless*
z_s: Optional[Union[ArrayLike, float]]
The source redshift.
*Unit: unitless*
x0: Optional[Union[ArrayLike, float]]
The x-coordinate of the lens center.
*Unit: arcsec*
y0: Optional[Union[ArrayLike, float]]
The y-coordinate of the lens center.
Rein: Optional[Union[ArrayLike, float]]
The Einstein radius of the lens.
*Unit: arcsec*
s: float
A smoothing factor, default is 0.0.
*Unit: arcsec*
"""
_null_params = {
"x0": 0.0,
"y0": 0.0,
"Rein": 1.0,
}
def __init__(
self,
cosmology: CosmologyType,
z_l: ZType = None,
z_s: ZType = None,
x0: Annotated[
Optional[Union[ArrayLike, float]],
"The x-coordinate of the lens center",
True,
] = None,
y0: Annotated[
Optional[Union[ArrayLike, float]],
"The y-coordinate of the lens center",
True,
] = None,
Rein: Annotated[
Optional[Union[ArrayLike, float]], "The Einstein radius of the lens", True
] = None,
s: Annotated[float, "A smoothing factor"] = 0.0,
name: NameType = None,
):
"""
Initialize the SIS lens model.
"""
super().__init__(cosmology, z_l, name=name, z_s=z_s)
self.x0 = Param("x0", x0, shape=(), units="arcsec")
self.y0 = Param("y0", y0, shape=(), units="arcsec")
self.Rein = Param("Rein", Rein, shape=(), units="arcsec", valid=(0, None))
self.s = s
[docs]
@forward
def reduced_deflection_angle(
self,
x: ArrayLike,
y: ArrayLike,
x0: Annotated[ArrayLike, "Param"],
y0: Annotated[ArrayLike, "Param"],
Rein: Annotated[ArrayLike, "Param"],
) -> tuple[ArrayLike, ArrayLike]:
"""
Calculate the deflection angle of the SIS lens.
Parameters
----------
x: ArrayLike
The x-coordinate of the lens.
*Unit: arcsec*
y: ArrayLike
The y-coordinate of the lens.
*Unit: arcsec*
Returns
-------
x_component: ArrayLike
Deflection Angle
*Unit: arcsec*
y_component: ArrayLike
Deflection Angle
*Unit: arcsec*
"""
return func.reduced_deflection_angle_sis(x0, y0, Rein, x, y, self.s)
[docs]
@forward
def potential(
self,
x: ArrayLike,
y: ArrayLike,
x0: Annotated[ArrayLike, "Param"],
y0: Annotated[ArrayLike, "Param"],
Rein: Annotated[ArrayLike, "Param"],
) -> ArrayLike:
"""
Compute the lensing potential of the SIS lens.
Parameters
----------
x: ArrayLike
The x-coordinate of the lens.
*Unit: arcsec*
y: ArrayLike
The y-coordinate of the lens.
*Unit: arcsec*
Returns
-------
ArrayLike
The lensing potential.
*Unit: arcsec^2*
"""
return func.potential_sis(x0, y0, Rein, x, y, self.s)
[docs]
@forward
def convergence(
self,
x: ArrayLike,
y: ArrayLike,
x0: Annotated[ArrayLike, "Param"],
y0: Annotated[ArrayLike, "Param"],
Rein: Annotated[ArrayLike, "Param"],
) -> ArrayLike:
"""
Calculate the projected mass density of the SIS lens.
Parameters
----------
x: ArrayLike
The x-coordinate of the lens.
*Unit: arcsec*
y: ArrayLike
The y-coordinate of the lens.
*Unit: arcsec*
Returns
-------
ArrayLike
The projected mass density.
*Unit: unitless*
"""
return func.convergence_sis(x0, y0, Rein, x, y, self.s)
