Fuzzy dark matter soliton core hosting a supermassive black hole as a dense low-mass perturber in strong gravitational lensing

TL;DR

This paper proposes that fuzzy dark matter soliton cores hosting supermassive black holes can serve as dense low-mass perturbers in strong gravitational lensing, explaining certain dense objects observed that lack known counterparts.

Contribution

It introduces a novel model of fuzzy dark matter soliton cores with SMBHs as efficient gravitational lensing perturbers, explaining dense low-mass objects without known counterparts.

Findings

A $ ext{~}10^6 M_ ext{sun}$ perturber can be explained by a FDM soliton core with an SMBH.

The model accounts for dense objects in lensing systems that resemble no known objects.

High SMBH mass scenarios align with heavy seed formation theories.

Abstract

Recent high-resolution imaging observations of strong lens systems reveal dense low-mass perturbers. We propose a soliton core, whose central density is boosted by a supermassive black hole (SMBH), in the fuzzy dark matter (FDM) model as an efficient perturber in strong gravitational lensing. The higher central density makes it less efficient in the tidal mass loss, and leads to the higher impact in gravitational lensing. We show that the mass profile of a $\sim 10^6M_\odot$ perturber in JVAS B1938+666, which does not resemble any known astronomical object, can be wel explained by a soliton core in the FDM model with the mass of $4\times 10^{-21}$eV hosting an SMBH with the mass of $4\times 10^5M_\odot$. The high mass of the SMBH may be explained by several scenarios that predcit heavy SMBH seeds such as the direct collapse black hole formation and primordial black holes.