GAML: Astrometric MicroLensing prediction using Gaia's data

This Python package searches for astrometric gravitational microlensing events given a list of lens-source pairs, and output quality assessments and astrometric and photometric microlensing effects of significant lensing events.

This project has evolved from Klüter's amlensing, with the following improvements:

• major overhaul to standardize and generalize the codebase
• substantial refactors to adapt for general lensing objects and background sources
  • E.g., allow setting their mass, mass error, and individual epochs
• makes it easier to prepare the input data files, which was abcent in the original code
• also a few bug fixes, which affects the result (most slightly)

For more detailed changes of this fork, see CHANGES.md and the commit log.

What does it do

1. GAML will perform several filters to exclude lenses and sources with low quality.
2. By predicting the motion over a specific time span, GAML determines the time and angular separation of lens-source closest approach.
3. By sampling the angular Einstein ring radius and angular separation, it calculates the astrometric and photometric observables of the gravitational microlensing event.
   • Such as centroid shift, positive image shift, centroid shift with a luminous lens, and magnification.

Although there are quite some changes from the original codebase, but it is still recommended to read Kluter 2022 for theoretical details.

Documentation

For further documentations, see the docs folder