tblenser

tblenser simulates the gravitational lensing of extra-galactic neutral hydrogen (HI) by foreground galaxies or clusters.

It can handle arbitrary lenses and is primarily focused on forward modelling, i.e. given a deflection map and a source model, it calculates the lensed image.

It can simulate HI disks using the Obreschkow et al. (2009) model, and marginalise over HI disk parameters through random sampling.

This software has been used in Blecher et al. (2019), with more results to come.

---

The structure of the code is as follows:

• Simulations are configured and run through a high-level driver script (see drivers folder);
• The driver script imports from the tblens module which should be installed (e.g. with pip);
• Deflection maps are either input to the pipeline or can be created by giving a mass model to the tblens.lens_creator.write_defmap function;
• tblens.HIDisk.HIDisk is a class which creates an HI disk;
• tblens.grid_creators.PositionGrid is a class for handling the basics of coordinate system generation;
• tblens.map_utils_core.DeflectionMap subclasses PositionGrid and handles the ray-tracing.