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Exploring the population of Galactic very-high-energy γ-ray sources

Steppa, C. ; Carlile, C. LU ; Dravins, D. LU orcid and Zmija, A. (2022) 395.
Abstract
At very high energies (VHE), the emission of γ rays is dominated by discrete sources. Due to the limited resolution and sensitivity of current-generation instruments, only a small fraction of the total Galactic population of VHE γ-ray sources has been detected significantly. The larger part of the population can be expected to contribute as a diffuse signal alongside emission originating from propagating cosmic rays. Without quantifying the source population, it is not possible to disentangle these two components. Based on the H.E.S.S. Galactic plane survey, a numerical approach has been taken to develop a model of the population of Galactic VHE γ-ray sources, which is shown to account accurately for the observational bias. We present... (More)
At very high energies (VHE), the emission of γ rays is dominated by discrete sources. Due to the limited resolution and sensitivity of current-generation instruments, only a small fraction of the total Galactic population of VHE γ-ray sources has been detected significantly. The larger part of the population can be expected to contribute as a diffuse signal alongside emission originating from propagating cosmic rays. Without quantifying the source population, it is not possible to disentangle these two components. Based on the H.E.S.S. Galactic plane survey, a numerical approach has been taken to develop a model of the population of Galactic VHE γ-ray sources, which is shown to account accurately for the observational bias. We present estimates of the absolute number of sources in the Galactic Plane and their contribution to the total VHE γ-ray emission for five different spatial source distributions. Prospects for CTA and its ability to constrain the model are discussed. Finally, first results of an extension of our modelling approach using machine learning to extract more information from the available data set are presented. © Copyright owned by the author(s) under the terms of the Creative Commons. (Less)
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author
; ; and
author collaboration
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publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Cosmic rays, Cosmology, Population statistics, Current generation, Discrete sources, Galactic plane surveys, Large parts, Limited resolution, Limited sensitivity, Numerical approaches, Source population, Two-component, Very high energies, Gamma rays
host publication
Proceedings of Science : 37th International Cosmic Ray Conference - 37th International Cosmic Ray Conference
volume
395
article number
798
external identifiers
  • scopus:85145255128
language
English
LU publication?
yes
id
f9edc354-b46a-457e-a53f-b220fb8b3f26
alternative location
https://pos.sissa.it/395/798/pdf
date added to LUP
2023-01-16 14:56:16
date last changed
2025-04-04 14:23:56
@inproceedings{f9edc354-b46a-457e-a53f-b220fb8b3f26,
  abstract     = {{At very high energies (VHE), the emission of γ rays is dominated by discrete sources. Due to the limited resolution and sensitivity of current-generation instruments, only a small fraction of the total Galactic population of VHE γ-ray sources has been detected significantly. The larger part of the population can be expected to contribute as a diffuse signal alongside emission originating from propagating cosmic rays. Without quantifying the source population, it is not possible to disentangle these two components. Based on the H.E.S.S. Galactic plane survey, a numerical approach has been taken to develop a model of the population of Galactic VHE γ-ray sources, which is shown to account accurately for the observational bias. We present estimates of the absolute number of sources in the Galactic Plane and their contribution to the total VHE γ-ray emission for five different spatial source distributions. Prospects for CTA and its ability to constrain the model are discussed. Finally, first results of an extension of our modelling approach using machine learning to extract more information from the available data set are presented. © Copyright owned by the author(s) under the terms of the Creative Commons.}},
  author       = {{Steppa, C. and Carlile, C. and Dravins, D. and Zmija, A.}},
  booktitle    = {{Proceedings of Science : 37th International Cosmic Ray Conference}},
  keywords     = {{Cosmic rays; Cosmology; Population statistics; Current generation; Discrete sources; Galactic plane surveys; Large parts; Limited resolution; Limited sensitivity; Numerical approaches; Source population; Two-component; Very high energies; Gamma rays}},
  language     = {{eng}},
  title        = {{Exploring the population of Galactic very-high-energy γ-ray sources}},
  url          = {{https://pos.sissa.it/395/798/pdf}},
  volume       = {{395}},
  year         = {{2022}},
}