Examples

These are demonstration notebooks for simulating mock IFU observations and performing step-by-step 3D datacube lensing and kinematic modeling on real astronomical data (MUSE observations of the Carousel lens, s4c).

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1. Mock Data Simulation

• simulate_lensed_galaxy.ipynb

  • Generates a synthetic 3D lensed galaxy datacube configured for JWST NIRSpec G235M observations.

  • Demonstrates lensing galaxy surface brightness evaluation, critical curve/caustic calculation, adding instrument noise, and exporting to FITS format.

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2. Step-by-Step Modeling Workflow (VLT MUSE Carousel Lens Data)

The s4c_* notebooks provide an end-to-end pipeline for modeling real MUSE IFU data of the Carousel lens system (Sheu et al. 2024). The truncated starting files can be found here. Notice the do_example_run variable at the beginning of some of the notebooks; when set to True, the notebooks will run a fast demonstration run which will run within a reasonable time. The recommended running order is as follows:

a. s4c_init.ipynb

• Datacube Initialization & Preprocessing

• Initializes the 3D datacube and performs spaxel-by-spaxel background continuum subtraction to isolate the lensed source galaxy signal.

b. s4c_flat_modeling_pl.ipynb

• 2D Photometric Modeling (Lenstronomy)

• Performs 2D photometric image modeling on the white-light collapsed image using Lenstronomy.

• Generates an initial parameterization using a primary power-law (EPL) lens mass convergence and a single Sersic source light profile.

c. s4c_flat_shapelets_pl.ipynb (Optional)

• Extended 2D Source Modeling with Shapelets

• Builds off s4c_flat_modeling_pl.ipynb by incorporating an additional shapelets component to model non-Sersic source light features.

d. s4c_iful_modeling_pl.ipynb

• 3D Datacube & Kinematic Modeling (IFULModel)

• Performs 3D IFU datacube modeling using the 2D lens parameterization from s4c_flat_modeling_pl.ipynb as a starting point.

• Models the source galaxy’s 3D kinematic profiles, including Line-of-Sight (LOS) velocity, velocity dispersion, and flux distribution.

e. s4c_compare_dist.ipynb

• Model Posterior Comparison & Visualization

• Plots and compares parameter posterior distributions and corner plots across the different model parameterizations.

• S4 initialization: building the image set
• Plot generation
• S4 flat (2D) lens modeling: Sersic source
• MCMC
• S4 flat (2D) lens modeling: Sersic + shapelets source
• MCMC
• S4 IFU lens modeling: source kinematics
• S4 posterior comparison
• Simulating a Lensed Galaxy Datacube