| Issue |
A&A
Volume 702, October 2025
|
|
|---|---|---|
| Article Number | A172 | |
| Number of page(s) | 11 | |
| Section | Extragalactic astronomy | |
| DOI | https://doi.org/10.1051/0004-6361/202554808 | |
| Published online | 17 October 2025 | |
Primordial black holes in the main lensing galaxy of FBQ 0951+2635
1
Departamento de Física Moderna, Universidad de Cantabria, Avda. de Los Castros s/n, E-39005 Santander, Spain
2
Instituto de Física de Cantabria (CSIC-UC), Avda. de Los Castros s/n, E-39005 Santander, Spain
3
Instituto de Física y Astronomía, Universidad de Valparaíso, Avda. Gran Bretaña 1111, Valparaíso, Chile
4
O.Ya. Usikov Institute for Radiophysics and Electronics, National Academy of Sciences of Ukraine, 12 Acad. Proscury St., UA-61085 Kharkiv, Ukraine
5
Escuela Superior de Ingeniería y Tecnología, Universidad Internacional de La Rioja (UNIR), Avda. Gran Vía Rey Juan Carlos I 41, E-26005 Logroño, Spain
⋆ Corresponding authors: disla003@ikasle.ehu.eus, goicol@unican.es
Received:
27
March 2025
Accepted:
26
August 2025
Although dark matter in galaxies may consist of elementary particles different from those that make up ordinary matter and that would be smoothly distributed (still undetected), the so-called primordial black holes (PBHs) formed soon after the initial Big Bang are also candidates to account for a certain fraction of mass in galaxies. In this paper, we focus on the main lensing galaxy (z = 0.260) of the doubly imaged, gravitationally lensed quasar FBQ 0951+2635 (z = 1.246) for probing possible PBH populations. Assuming that the mass of the galaxy is due to smoothly distributed matter (SDM), stars, and PBHs, the 16-yr microlensing variability observations were compared in detail with simulated microlensing signals generated by 90 different physical scenarios. Among other details, the simulated signals were sampled as the observed one, and the observed variability in its entirety and over the long term were used separately for comparison. While none of the scenarios considered can reproduce the overall observed signal, the observed long-term variability favours a small mass fraction in PBHs with a mass of the order of the mean stellar mass. Furthermore, it is possible to obtain strong constraints on the galaxy mass fraction in Jupiter-mass PBHs, provided that a reverberation-based measurement of the source size is available and relatively small. To constrain the mass fraction in ∼10 M⊙ PBHs, light curves five times longer are probably required.
Key words: gravitational lensing: micro / galaxies: halos / dark matter / quasars: individual: FBQ 0951+2635
© The Authors 2025
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This article is published in open access under the Subscribe to Open model. Subscribe to A&A to support open access publication.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.