Deepening gamma-ray point-source catalogues with sub-threshold information
Abstract
We propose a novel statistical method to extend Fermi-LAT catalogues of high-latitude γ-ray sources below their nominal threshold. To do so, we rely on the determination of the differential source-count distribution of sub-threshold sources which only provides the statistical flux distribution of faint sources. By simulating ensembles of synthetic skies, we assess quantitatively the likelihood for pixels in the sky with relatively low-test statistics to be due to sources, therefore complementing the source-count distribution with spatial information. Besides being useful to orient efforts towards multi-messenger and multi-wavelength identification of new γ-ray sources, we expect the results to be especially advantageous for statistical applications such as cross-correlation analyses.
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- March 2024
- DOI:
- 10.1088/1475-7516/2024/03/055
- arXiv:
- arXiv:2306.16483
- Bibcode:
- 2024JCAP...03..055A
- Keywords:
-
- gamma ray theory;
- Frequentist statistics;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 12 pages, 3 figures. For the associated Python code, see https://doi.org/10.5281/zenodo.8070852