Fast computation of quadrupole and hexadecapole approximations in microlensing with a single point-source evaluation

Arnaud Cassan (1)

1 IAP - Institut d'Astrophysique de Paris

The exoplanet detection rate from gravitational microlensing has grown significantly in recent years thanks to a great enhancement of resources and improved observational strategy. Current observatories include ground-based wide-field and/or robotic world-wide networks of telescopes, as well as space-based observatories such as satellites Spitzer or Kepler/K2. This results in a large quantity of data to be processed and analysed, which is a challenge for modelling codes because of the complexity of the parameter space to be explored and the intensive computations required to evaluate the models. In this work, I present a method that allows to compute the quadrupole and hexadecapole approximations of the finite-source magnification with more efficiency than previously available codes, with routines about six times and four times faster, respectively. The quadrupole takes just about twice the time of a point-source evaluation, which advocates for generalizing its use to large portions of the light curves. The corresponding routines are available as open-source python codes.

Mots clés: gravitational lensing: micro; methods: numerical; planets and satellites: detection; Astrophysics - Earth and Planetary Astrophysics; Astrophysics - Instrumentation and Methods for Astrophysics

Domaines: Planète et Univers [physics]; Astrophysique [astro-ph]

Arnaud Cassan. Fast computation of quadrupole and hexadecapole approximations in microlensing with a single point-source evaluation. Monthly Notices of the Royal Astronomical Society, 2017, 468, pp.3993-3999. ⟨10.1093/mnras/stx849⟩. ⟨insu-03747456⟩