caustics.light package

caustics.light package#

Subpackages#

Submodules#

caustics.light.base module#

class caustics.light.base.Source(name: str | None = None, **kwargs)[source]#

Bases: Module

This is an abstract base class used to represent a source in a strong gravitational lensing system. It provides the basic structure and required methods that any derived source class should implement. The Source class inherits from the Module class, implying that it contains parameters that can be optimized or manipulated.

The class introduces one abstract method, brightness, that must be implemented in any concrete subclass. This method calculates the brightness of the source at given coordinates.

abstract brightness(x: ArrayLike, y: ArrayLike, *args, **kwargs) → ArrayLike[source]#

Abstract method that calculates the brightness of the source at the given coordinates. This method is expected to be implemented in any class that derives from Source.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given coordinate(s). The exact form of the output will depend on the specific implementation in the derived class.

Return type:

ArrayLike

Notes

This method must be overridden in any class that inherits from Source.

Note that the source redshift z_s is not included as an argument since most sources don’t need to know their redshift, it is instead held by the lens object.

caustics.light.light_stack module#

class caustics.light.light_stack.LightStack(light_models: Annotated[Tuple[Source], 'a list of light models to sum their brightnesses'], name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

LightStack is a subclass of the abstract class Source which takes the sum of multiple Source models to make a single brightness model.

light_models#

A list of light models to sum.

Type:

List[Source]

brightness(x, y, **kwargs)[source]#

Implements the brightness method for Sersic. The brightness at a given point is determined by the Sersic profile formula.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given point(s). The output tensor has the same shape as x and y.

Unit: flux

Return type:

ArrayLike

caustics.light.pixelated module#

class caustics.light.pixelated.Pixelated(image: Annotated[ArrayLike | None, 'The source image from which brightness values will be interpolated.', True, 'flux'] = None, x0: Annotated[ArrayLike | float | None, "The x-coordinate of the source image's center.", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the source image's center.", True] = None, pixelscale: Annotated[ArrayLike | float | None, 'The pixelscale of the source image in the lens plane', True, 'arcsec/pixel'] = None, scale: Annotated[ArrayLike | float | None, 'A scale factor to multiply by the image', True, 'flux'] = 1.0, shape: Annotated[tuple[int | None, ...], 'The shape of the source image.'] = (None, None), name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

Pixelated is a subclass of the abstract class Source. It represents the brightness profile of source with a pixelated grid of intensity values.

This class provides a concrete implementation of the brightness method required by the Source superclass. In this implementation, brightness is determined by interpolating values from the provided source image.

x0#

The x-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

y0#

The y-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

image#

The source image from which brightness values will be interpolated.

Unit: flux

Type:

ArrayLike, optional

pixelscale#

The pixelscale of the source image in the lens plane.

Unit: arcsec/pixel

Type:

ArrayLike, optional

shape#

The shape of the source image.

Type:

Tuple of ints, optional

brightness(x, y, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], image: Annotated[ArrayLike, 'Param'], pixelscale: Annotated[ArrayLike, 'Param'], scale: Annotated[ArrayLike, 'Param'], padding_mode: str = 'zeros')[source]#

Implements the brightness method for Pixelated. The brightness at a given point is determined by interpolating values from the source image.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given coordinate(s). The brightness is determined by interpolating values from the source image.

Unit: flux

Return type:

ArrayLike

caustics.light.pixelated_time module#

class caustics.light.pixelated_time.PixelatedTime(cube: Annotated[ArrayLike | None, 'The source image cube from which brightness values will be interpolated.', True, 'flux'] = None, x0: Annotated[ArrayLike | float | None, "The x-coordinate of the source image's center.", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the source image's center.", True] = None, pixelscale: Annotated[ArrayLike | float | None, 'The pixelscale of the source image in the lens plane', False, 'arcsec/pixel'] = None, t_end: Annotated[ArrayLike | float | None, 'The end time of the source image cube.', False, 'seconds'] = None, scale: Annotated[ArrayLike | float | None, 'A scale factor to multiply by the image', True, 'flux'] = 1.0, shape: Annotated[tuple[int, ...] | None, 'The shape of the source image.'] = None, name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

PixelatedTime is a subclass of the abstract class Source. It represents the brightness profile of source with a pixelated grid of intensity values that also may vary over time.

This class provides a concrete implementation of the brightness method required by the Source superclass. In this implementation, brightness is determined by interpolating values from the provided source image.

x0#

The x-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

y0#

The y-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

cube#

The source image cube from which brightness values will be interpolated.

Unit: flux

Type:

ArrayLike, optional

pixelscale#

The pixelscale of the source image in the lens plane.

Unit: arcsec/pixel

Type:

ArrayLike, optional

t_end#

The end time of the source image cube. Time in the cube is assumed to be in the range (0, t_end) in seconds.

Unit: seconds

Type:

ArrayLike, optional

shape#

The shape of the source image and time dim.

Type:

Tuple of ints, optional

brightness(x, y, t, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], cube: Annotated[ArrayLike, 'Param'], scale: Annotated[ArrayLike, 'Param'])[source]#

Implements the brightness method for Pixelated. The brightness at a given point is determined by interpolating values from the source image.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • t (ArrayLike) –

    The time coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: seconds

Returns:

The brightness of the source at the given coordinate(s). The brightness is determined by interpolating values from the source image.

Unit: flux

Return type:

ArrayLike

caustics.light.sersic module#

class caustics.light.sersic.Sersic(x0: Annotated[ArrayLike | float | None, "The x-coordinate of the Sersic source's center", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the Sersic source's center", True] = None, q: Annotated[ArrayLike | float | None, 'The axis ratio of the Sersic source', True] = None, phi: Annotated[ArrayLike | float | None, 'The orientation of the Sersic source (position angle)', True] = None, n: Annotated[ArrayLike | float | None, 'The Sersic index, which describes the degree of concentration of the source', True] = None, Re: Annotated[ArrayLike | float | None, 'The scale length of the Sersic source', True] = None, Ie: Annotated[ArrayLike | float | None, 'The intensity at the effective radius', True] = None, s: Annotated[float, 'A small constant for numerical stability'] = 0.0, use_lenstronomy_k: Annotated[bool, 'A flag indicating whether to use lenstronomy to compute the value of k.'] = False, angle_system: str = 'q_phi', e1: ArrayLike | float | None = None, e2: ArrayLike | float | None = None, c1: ArrayLike | float | None = None, c2: ArrayLike | float | None = None, name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Angle_Mixin, Source

Sersic is a subclass of the abstract class Source. It represents a source in a strong gravitational lensing system that follows a Sersic profile, a mathematical function that describes how the intensity I of a galaxy varies with distance r from its center.

The Sersic profile is often used to describe elliptical galaxies and spiral galaxies’ bulges.

x0#

The x-coordinate of the Sersic source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

y0#

The y-coordinate of the Sersic source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

q#

The axis ratio of the Sersic source.

Unit: unitless

Type:

Optional[ArrayLike]

phi#

The orientation of the Sersic source (position angle).

Unit: radians

Type:

Optional[ArrayLike]

n#

The Sersic index, which describes the degree of concentration of the source.

Unit: unitless

Type:

Optional[ArrayLike]

Re#

The scale length of the Sersic source.

Unit: arcsec

Type:

Optional[ArrayLike]

Ie#

The intensity at the effective radius.

Unit: flux

Type:

Optional[ArrayLike]

s#

A small constant for numerical stability.

Unit: arcsec

Type:

float

lenstronomy_k_mode#

A flag indicating whether to use lenstronomy to compute the value of k.

Type:

bool

brightness(x, y, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], q: Annotated[ArrayLike, 'Param'], phi: Annotated[ArrayLike, 'Param'], n: Annotated[ArrayLike, 'Param'], Re: Annotated[ArrayLike, 'Param'], Ie: Annotated[ArrayLike, 'Param'])[source]#

Implements the brightness method for Sersic. The brightness at a given point is determined by the Sersic profile formula.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given point(s). The output tensor has the same shape as x and y.

Unit: flux

Return type:

ArrayLike

Notes

The Sersic profile is defined as: I(r) = Ie * exp(-k * ((r / r_e)^(1/n) - 1)), where Ie is the intensity at the effective radius r_e, n is the Sersic index that describes the concentration of the source, and k is a parameter that depends on n. In this implementation, we use elliptical coordinates ex and ey, and the transformation from Cartesian coordinates is handled by to_elliptical. The value of k can be calculated in two ways, controlled by lenstronomy_k_mode. If lenstronomy_k_mode is True, we use the approximation from Lenstronomy, otherwise, we use the approximation from Ciotti & Bertin (1999).

caustics.light.star_source module#

class caustics.light.star_source.StarSource(x0: Annotated[ArrayLike | float | None, "The x-coordinate of the star source's center", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the star source's center", True] = None, theta_s: Annotated[ArrayLike | float | None, 'The radius of the star source', True] = None, Ie: Annotated[ArrayLike | float | None, 'The intensity at the effective radius', True] = None, gamma: Annotated[ArrayLike | float | None, 'The linear limb darkening coefficient', True] = None, name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

Star is a subclass of the abstract class Source. It represents a star source in a gravitational lensing system.

The Star profile is meant to describe individual light sources.

x0#

The x-coordinate of the Star source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

y0#

The y-coordinate of the Star source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

theta_s#

The radius of the star.

Unit: arcsec

Type:

Optional[ArrayLike]

Ie#

The intensity at the center of the star.

Unit: flux

Type:

Optional[ArrayLike]

gamma#

The linear limb darkening coefficient.

Unit: unitless

Type:

Optional[ArrayLike]

brightness(x, y, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], theta_s: Annotated[ArrayLike, 'Param'], Ie: Annotated[ArrayLike, 'Param'], gamma: Annotated[ArrayLike, 'Param'])[source]#

Implements the brightness method for star. This method calculates the brightness of the source at the given point(s).

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given point(s). The output tensor has the same shape as x and y.

Unit: flux

Return type:

ArrayLike

Module contents#

class caustics.light.LightStack(light_models: Annotated[Tuple[Source], 'a list of light models to sum their brightnesses'], name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

LightStack is a subclass of the abstract class Source which takes the sum of multiple Source models to make a single brightness model.

light_models#

A list of light models to sum.

Type:

List[Source]

brightness(x, y, **kwargs)[source]#

Implements the brightness method for Sersic. The brightness at a given point is determined by the Sersic profile formula.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given point(s). The output tensor has the same shape as x and y.

Unit: flux

Return type:

ArrayLike

class caustics.light.Pixelated(image: Annotated[ArrayLike | None, 'The source image from which brightness values will be interpolated.', True, 'flux'] = None, x0: Annotated[ArrayLike | float | None, "The x-coordinate of the source image's center.", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the source image's center.", True] = None, pixelscale: Annotated[ArrayLike | float | None, 'The pixelscale of the source image in the lens plane', True, 'arcsec/pixel'] = None, scale: Annotated[ArrayLike | float | None, 'A scale factor to multiply by the image', True, 'flux'] = 1.0, shape: Annotated[tuple[int | None, ...], 'The shape of the source image.'] = (None, None), name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

Pixelated is a subclass of the abstract class Source. It represents the brightness profile of source with a pixelated grid of intensity values.

This class provides a concrete implementation of the brightness method required by the Source superclass. In this implementation, brightness is determined by interpolating values from the provided source image.

x0#

The x-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

y0#

The y-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

image#

The source image from which brightness values will be interpolated.

Unit: flux

Type:

ArrayLike, optional

pixelscale#

The pixelscale of the source image in the lens plane.

Unit: arcsec/pixel

Type:

ArrayLike, optional

shape#

The shape of the source image.

Type:

Tuple of ints, optional

brightness(x, y, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], image: Annotated[ArrayLike, 'Param'], pixelscale: Annotated[ArrayLike, 'Param'], scale: Annotated[ArrayLike, 'Param'], padding_mode: str = 'zeros')[source]#

Implements the brightness method for Pixelated. The brightness at a given point is determined by interpolating values from the source image.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given coordinate(s). The brightness is determined by interpolating values from the source image.

Unit: flux

Return type:

ArrayLike

class caustics.light.PixelatedTime(cube: Annotated[ArrayLike | None, 'The source image cube from which brightness values will be interpolated.', True, 'flux'] = None, x0: Annotated[ArrayLike | float | None, "The x-coordinate of the source image's center.", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the source image's center.", True] = None, pixelscale: Annotated[ArrayLike | float | None, 'The pixelscale of the source image in the lens plane', False, 'arcsec/pixel'] = None, t_end: Annotated[ArrayLike | float | None, 'The end time of the source image cube.', False, 'seconds'] = None, scale: Annotated[ArrayLike | float | None, 'A scale factor to multiply by the image', True, 'flux'] = 1.0, shape: Annotated[tuple[int, ...] | None, 'The shape of the source image.'] = None, name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

PixelatedTime is a subclass of the abstract class Source. It represents the brightness profile of source with a pixelated grid of intensity values that also may vary over time.

This class provides a concrete implementation of the brightness method required by the Source superclass. In this implementation, brightness is determined by interpolating values from the provided source image.

x0#

The x-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

y0#

The y-coordinate of the source image’s center.

Unit: arcsec

Type:

ArrayLike, optional

cube#

The source image cube from which brightness values will be interpolated.

Unit: flux

Type:

ArrayLike, optional

pixelscale#

The pixelscale of the source image in the lens plane.

Unit: arcsec/pixel

Type:

ArrayLike, optional

t_end#

The end time of the source image cube. Time in the cube is assumed to be in the range (0, t_end) in seconds.

Unit: seconds

Type:

ArrayLike, optional

shape#

The shape of the source image and time dim.

Type:

Tuple of ints, optional

brightness(x, y, t, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], cube: Annotated[ArrayLike, 'Param'], scale: Annotated[ArrayLike, 'Param'])[source]#

Implements the brightness method for Pixelated. The brightness at a given point is determined by interpolating values from the source image.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • t (ArrayLike) –

    The time coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: seconds

Returns:

The brightness of the source at the given coordinate(s). The brightness is determined by interpolating values from the source image.

Unit: flux

Return type:

ArrayLike

class caustics.light.Sersic(x0: Annotated[ArrayLike | float | None, "The x-coordinate of the Sersic source's center", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the Sersic source's center", True] = None, q: Annotated[ArrayLike | float | None, 'The axis ratio of the Sersic source', True] = None, phi: Annotated[ArrayLike | float | None, 'The orientation of the Sersic source (position angle)', True] = None, n: Annotated[ArrayLike | float | None, 'The Sersic index, which describes the degree of concentration of the source', True] = None, Re: Annotated[ArrayLike | float | None, 'The scale length of the Sersic source', True] = None, Ie: Annotated[ArrayLike | float | None, 'The intensity at the effective radius', True] = None, s: Annotated[float, 'A small constant for numerical stability'] = 0.0, use_lenstronomy_k: Annotated[bool, 'A flag indicating whether to use lenstronomy to compute the value of k.'] = False, angle_system: str = 'q_phi', e1: ArrayLike | float | None = None, e2: ArrayLike | float | None = None, c1: ArrayLike | float | None = None, c2: ArrayLike | float | None = None, name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Angle_Mixin, Source

Sersic is a subclass of the abstract class Source. It represents a source in a strong gravitational lensing system that follows a Sersic profile, a mathematical function that describes how the intensity I of a galaxy varies with distance r from its center.

The Sersic profile is often used to describe elliptical galaxies and spiral galaxies’ bulges.

x0#

The x-coordinate of the Sersic source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

y0#

The y-coordinate of the Sersic source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

q#

The axis ratio of the Sersic source.

Unit: unitless

Type:

Optional[ArrayLike]

phi#

The orientation of the Sersic source (position angle).

Unit: radians

Type:

Optional[ArrayLike]

n#

The Sersic index, which describes the degree of concentration of the source.

Unit: unitless

Type:

Optional[ArrayLike]

Re#

The scale length of the Sersic source.

Unit: arcsec

Type:

Optional[ArrayLike]

Ie#

The intensity at the effective radius.

Unit: flux

Type:

Optional[ArrayLike]

s#

A small constant for numerical stability.

Unit: arcsec

Type:

float

lenstronomy_k_mode#

A flag indicating whether to use lenstronomy to compute the value of k.

Type:

bool

brightness(x, y, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], q: Annotated[ArrayLike, 'Param'], phi: Annotated[ArrayLike, 'Param'], n: Annotated[ArrayLike, 'Param'], Re: Annotated[ArrayLike, 'Param'], Ie: Annotated[ArrayLike, 'Param'])[source]#

Implements the brightness method for Sersic. The brightness at a given point is determined by the Sersic profile formula.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given point(s). The output tensor has the same shape as x and y.

Unit: flux

Return type:

ArrayLike

Notes

The Sersic profile is defined as: I(r) = Ie * exp(-k * ((r / r_e)^(1/n) - 1)), where Ie is the intensity at the effective radius r_e, n is the Sersic index that describes the concentration of the source, and k is a parameter that depends on n. In this implementation, we use elliptical coordinates ex and ey, and the transformation from Cartesian coordinates is handled by to_elliptical. The value of k can be calculated in two ways, controlled by lenstronomy_k_mode. If lenstronomy_k_mode is True, we use the approximation from Lenstronomy, otherwise, we use the approximation from Ciotti & Bertin (1999).

class caustics.light.Source(name: str | None = None, **kwargs)[source]#

Bases: Module

This is an abstract base class used to represent a source in a strong gravitational lensing system. It provides the basic structure and required methods that any derived source class should implement. The Source class inherits from the Module class, implying that it contains parameters that can be optimized or manipulated.

The class introduces one abstract method, brightness, that must be implemented in any concrete subclass. This method calculates the brightness of the source at given coordinates.

abstract brightness(x: ArrayLike, y: ArrayLike, *args, **kwargs) → ArrayLike[source]#

Abstract method that calculates the brightness of the source at the given coordinates. This method is expected to be implemented in any class that derives from Source.

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given coordinate(s). The exact form of the output will depend on the specific implementation in the derived class.

Return type:

ArrayLike

Notes

This method must be overridden in any class that inherits from Source.

Note that the source redshift z_s is not included as an argument since most sources don’t need to know their redshift, it is instead held by the lens object.

class caustics.light.StarSource(x0: Annotated[ArrayLike | float | None, "The x-coordinate of the star source's center", True] = None, y0: Annotated[ArrayLike | float | None, "The y-coordinate of the star source's center", True] = None, theta_s: Annotated[ArrayLike | float | None, 'The radius of the star source', True] = None, Ie: Annotated[ArrayLike | float | None, 'The intensity at the effective radius', True] = None, gamma: Annotated[ArrayLike | float | None, 'The linear limb darkening coefficient', True] = None, name: Annotated[str | None, 'Name of the source'] = None)[source]#

Bases: Source

Star is a subclass of the abstract class Source. It represents a star source in a gravitational lensing system.

The Star profile is meant to describe individual light sources.

x0#

The x-coordinate of the Star source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

y0#

The y-coordinate of the Star source’s center.

Unit: arcsec

Type:

Optional[ArrayLike]

theta_s#

The radius of the star.

Unit: arcsec

Type:

Optional[ArrayLike]

Ie#

The intensity at the center of the star.

Unit: flux

Type:

Optional[ArrayLike]

gamma#

The linear limb darkening coefficient.

Unit: unitless

Type:

Optional[ArrayLike]

brightness(x, y, x0: Annotated[ArrayLike, 'Param'], y0: Annotated[ArrayLike, 'Param'], theta_s: Annotated[ArrayLike, 'Param'], Ie: Annotated[ArrayLike, 'Param'], gamma: Annotated[ArrayLike, 'Param'])[source]#

Implements the brightness method for star. This method calculates the brightness of the source at the given point(s).

Parameters:

  • x (ArrayLike) –

    The x-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

  • y (ArrayLike) –

    The y-coordinate(s) at which to calculate the source brightness. This could be a single value or a tensor of values.

    Unit: arcsec

Returns:

The brightness of the source at the given point(s). The output tensor has the same shape as x and y.

Unit: flux

Return type:

ArrayLike