Fast simulations of extragalactic microlensing^⋆

¹ GLENDAMA Team, Dpto. de Física Moderna, Universidad de Cantabria, Avda. de Los Castros s/n, 39005 Santander, Spain
e-mail: goicol@unican.es
² O.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, 12 Acad. Proscury St., 61085 Kharkiv, Ukraine
e-mail: vshal@ukr.net
³ Institute of Astronomy of V.N. Karazin Kharkiv National University, Svobody Sq. 4, 61022 Kharkiv, Ukraine
⁴ Dpto. de Lenguajes y Ciencias de la Computación, E.T.S.I Informática, Campus de Teatinos, Universidad de Málaga, Bulevar Louis Pasteur 35, 29071 Málaga, Spain
e-mail: gilmerino@uma.es

Received: 10 February 2021
Accepted: 13 June 2021

Abstract

We present a new and very fast method for producing microlensing magnification maps at high optical depths. It is based on the combination of two approaches: (a) the two-dimensional Poisson solver for a deflection potential and (b) inverse polygon mapping. With our method we extremely reduce the computing time for the generation of magnification patterns and avoid the use of highly demanding computer resources. For example, the generation of a magnification map of size 2000 × 2000 pixels, covering a region of 20 Einstein radii, takes a few seconds on a state-of-the-art laptop. The method presented here will facilitate the massive production of magnification maps for extragalactic microlensing studies within the forthcoming surveys without the need for large computer clusters. The modest demand of computer power and a fast execution time allow the code developed here to be placed on a standard server and thus provide the public online access through a web-based interface.