On the Clustering Bias of Unresolved Gamma-Ray Sources
Abstract
The Unresolved γ-Ray Background (UGRB) encodes the collective emission of source populations that are too faint to be detected individually, and its cross-correlation with tracers of the large-scale structure has emerged as a powerful tool to characterize those populations. In this work, we analyze the weak-lensing--UGRB cross-correlation using a reference blazar model. By modeling the relation between blazar γ-ray luminosity and host-halo mass, we infer the average linear bias ⟨ b(z) ⟩ and host-halo mass ⟨ M(z) ⟩ of the unresolved blazar population. We find that the signal is dominated by moderately biased sources, with ⟨ b ⟩ ≳ 2 at z≃ 1, hosted by halos with ⟨ M ⟩ ∼ 𝒪(1013 M⊙). Repeating the analysis with a misaligned-AGN model yields consistent bias values, indicating that the result is determined by the clustering properties of the UGRB rather than by the details of the γ-ray source model.
Related
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BibTeX
@misc{thakore2026clustering,
title = {{On the Clustering Bias of Unresolved Gamma-Ray Sources}},
author = {Bhashin A. Thakore and Marco Regis and Michela Negro and Stefano Camera and Daniel Gruen and Nicolao Fornengo and Aaron J. Roodman},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.19259},
eprint = {2609.19259},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.19259},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - On the Clustering Bias of Unresolved Gamma-Ray Sources
AU - Bhashin A. Thakore
AU - Marco Regis
AU - Michela Negro
AU - Stefano Camera
AU - Daniel Gruen
AU - Nicolao Fornengo
AU - Aaron J. Roodman
PY - 2026
DA - 2026/09/16
PB - arXiv
DO - 10.48550/arxiv.2609.19259
UR - https://arxiv.org/abs/2609.19259
AB - The Unresolved γ-Ray Background (UGRB) encodes the collective emission of source populations that are too faint to be detected individually, and its cross-correlation with tracers of the large-scale structure has emerged as a powerful tool to characterize those populations. In this work, we analyze the weak-lensing--UGRB cross-correlation using a reference blazar model. By modeling the relation between blazar γ-ray luminosity and host-halo mass, we infer the average linear bias ⟨ b(z) ⟩ and host-halo mass ⟨ M(z) ⟩ of the unresolved blazar population. We find that the signal is dominated by moderately biased sources, with ⟨ b ⟩ ≳ 2 at z≃ 1, hosted by halos with ⟨ M ⟩ ∼ 𝒪(10^13 M_⊙). Repeating the analysis with a misaligned-AGN model yields consistent bias values, indicating that the result is determined by the clustering properties of the UGRB rather than by the details of the γ-ray source model.
ER -