| Issue |
A&A
Volume 711, July 2026
|
|
|---|---|---|
| Article Number | A191 | |
| Number of page(s) | 7 | |
| Section | Cosmology (including clusters of galaxies) | |
| DOI | https://doi.org/10.1051/0004-6361/202558336 | |
| Published online | 14 July 2026 | |
Effect of primordial black holes on the global 21 cm signal
Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV, Groningen, The Netherlands
★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
1
December
2025
Accepted:
15
June
2026
Abstract
The 21 cm global signal, a treasure trove of information about the nature of the first luminous sources of the Universe, has traditionally been modelled assuming that these early sources were predominantly star-forming galaxies. However, recent observations by the James Webb Space Telescope (JWST) have revealed several active galactic nuclei (AGNs) as early as z ∼ 10−10.4. In light of this, it is important to investigate the contribution of such AGNs to the 21 cm signal. Assuming that these AGNs are seeded by primordial black holes (PBHs) and employing an analytical PBH model, consistent with existing cosmological and astrophysical constraints, we show that these exotic objects can have a significant impact on the redshift evolution of the global signal.
Key words: galaxies: high-redshift / quasars: general / cosmology: theory / dark ages / reionization / first stars
© The Authors 2026
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. This email address is being protected from spambots. You need JavaScript enabled to view it. 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.