Point Sources#
Point sources arise when the background object is compact (e.g. a quasar, supernova, or compact radio source) and is modelled by its image-plane positions, flux ratios, and/or time delays rather than by a resolved surface-brightness distribution.
Dataset#
Data structures holding the observed positions, fluxes, and time delays of one or more named point sources.
A collection of the data component that can be used for point-source model-fitting, for example fitting the observed positions of a a strongly lensed quasar or supernovae or in strong lens cluster modeling, where there may be many tens or hundreds of individual source galaxies each of which are modeled as a point source. |
Solver#
The PointSolver finds the image-plane positions that correspond to a given
source-plane coordinate by solving the lens equation numerically via a triangle-tiling
approach.
Determine the image plane coordinates that are traced to be a source plane coordinate. |
Fitting#
Fit classes for point-source positions, flux ratios, and time delays. FitPointDataset
orchestrates all active components; the individual fit classes can also be used standalone.
Fits a point source dataset using a Tracer object, where the following components of the point source data may be fitted: |
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Abstract class to fit the positions of a point source dataset using a Tracer object with an image-plane chi-squared, where the specific implementation of the image-plane chi-squared is defined in the sub-class. |
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Abstract class to fit the positions of a point source dataset using a Tracer object with an image-plane chi-squared, where the specific implementation of the image-plane chi-squared is defined in the sub-class. |
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Abstract class to fit the positions of a point source dataset using a Tracer object with an image-plane chi-squared, where the specific implementation of the image-plane chi-squared is defined in the sub-class. |
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Fits the positions of a a point source dataset using a Tracer object with a source-plane chi-squared based on the separation of image-plane positions ray-traced to the source-plane compared to the centre of the source galaxy. |
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Fits the fluxes of a a point source dataset using a Tracer object, where every model flux of the point-source is compared with its observed flux. |
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Fits the time delays of a point source dataset using a Tracer object, where every model time delay of the point-source is compared with its observed time delay. |
Position Likelihood#
PositionsLH adds a penalty to the log likelihood when the observed image positions do
not self-consistently trace back to the same source-plane location, guiding the non-linear
search toward physically consistent mass models.
The PositionsLH objects add a penalty term to the likelihood of the PyAutoLens log_likelihood_function defined in the Analysis classes. |
Analysis#
Fits a lens model to a point source dataset (e.g. positions, fluxes, time delays) via a non-linear search. |