Strong gravitational lensing of explosive transients

Abstract

Recent rapid progress in time domain surveys makes it possible to detect various types of explosive transients in the Universe in large numbers, some of which will be gravitationally lensed into multiple images. Although a large number of strongly lensed distant galaxies and quasars have already been discovered, strong lensing of explosive transients opens up new applications, including improved measurements of cosmological parameters, powerful probes of small scale structure of the Universe, and new observational tests of dark matter scenarios, thanks to their rapidly evolving light curves as well as their compact sizes. In particular, the compactness of these transient events indicates that the wave optics effect plays an important role in some cases, which can lead to totally new applications of these lensing events. Recently we have witnessed first discoveries of strongly lensed supernovae, and strong lensing events of other types of explosive transients such as gamma-ray bursts, fast radio bursts, and gravitational waves from compact binary mergers are expected to be observed soon. In this review article, we summarize the current state of research on strong gravitational lensing of explosive transients and discuss future prospects.

Properties and Astrophysical Implications of the 150 M⊙ Binary Black Hole Merger GW190521

“…For a given observed GW signal, the luminosity distance to the source, and thus its redshift, may then be much larger than in the absence of lensing. Strong lensing is expected to be relatively rare at current detector sensitivities, with 1 in every 100-1000 detected events strongly lensed by individual galaxies (Holz & Wald 1998;Li et al 2018;Ng et al 2018;Oguri 2018) and a similarly low rate for lensing by galaxy clusters (Smith et al 2018;Oguri 2019).…”

LENSINGGW: a PYTHON package for lensing of gravitational waves

“…One example of such an avenue is gravitationally lensed GWs, the first of which may be possible to observe in the next few years (Ng et al 2018;Li et al 2018;Oguri 2018). It has been suggested that lensed GWs might offer interesting applications in fundamental physics, astrophysics, and cosmology (Sereno et al 2011;Liao et al 2017;Collett & Bacon 2017;Fan et al 2017;Baker & Trodden 2017;Lai et al 2018;Dai et al 2018;Mukherjee et al 2019;Oguri 2019;Pang et al 2020;Jung & Shin 2019;Cao et al 2019;Hou et al 2020;Sun & Fan 2019;Hannuksela et al 2020).…”

Image Simulations for Strong and Weak Gravitational Lensing

“…It is therefore useful and customary to identify several regimes of lensing depending on the particular configuration of the system at hand (Dodelson 2017;Schneider et al 1992). The case in which multiple images and arcs are produced is known as strong lensing (Oguri 2019;Treu 2010), whereas the less dramatic-but much more common-case, in which the lensing signal is so subtle that it can only be detected statistically, is known as weak lensing (Bartelmann and Maturi 2017;Schneider 2005;Bartelmann and Schneider 2001). A third regime known as microlensing uses the magnification of the image of a source star when it is aligned with another lensing star along the line of sight.…”