Gravitational lensing effects of supermassive black holes in cluster environments

Abstract: This study explores the gravitational lensing effects of supermassive black holes (SMBHs) residing in galaxy clusters. While most galaxies, are expected to harbour central SMBHs, recent work from high-resolution simulations predicts an additional population of wandering SMBHs. Though the masses of these SMBHs are a minor perturbation on the larger scale and individual galaxy scale dark matter components, they can impact statistical lensing properties and individual lensed image configurations. Probing for these potentially detectable observational signatures, we find that SMBHs do not imprint any statistically significant detectable evidence in either the magnification distribution or the integrated shear profile. However, we find detectable signatures via rare, higher-order strong lensing image configurations. Here, we investigate specific cases of lensed image geometries and report that a massive, near point-like, potential causes the following detectable effects: (i) positional asymmetries in multiply imaged galaxies; (ii) the generation of extra images; (iii) the production of magnification asymmetries; and (iv) the apparent disappearance of a counter-image in a lensed system. Image splitting inside the cluster tangential critical curve, is likely the most prevalent notable observational signature. We demonstrate these possibilities with two cases of observed giant arcs (SGASJ003341.5+024217 and RXJ1347.5-1145) wherein specific image configurations could be reproduced with SMBHs. Future observations with high-resolution instrumentation (e.g. MAVIS-Very Large Telescope, MICADO-Extremely Large Telescope, and the upgraded ngVLA, along with data from the EUCLID \& Nancy Grace Roman Space Telescopes and the Rubin LSST Observatory are likely to allow us to probe these unique SMBHs lensing signatures.

We show below some extra materials and animations to further visualise the effects of an SMBH on the lensing configurations

We also share our mock cluster here