Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

H.E.S.S. observations of composite Seyfert-starburst galaxies

H. E. S. S. Collaboration, A. Acharyya, F. Aharonian, H. Ashkar, M. Backes, V. Barbosa Martins, R. Batzofin, Y. Becherini, D. Berge, M. Böttcher, C. Boisson, J. Bolmont, J. Borowska, F. Brun, B. Bruno, C. Burger-Scheidlin, S. Casanova, J. Celic, M. Cerruti, S. Chandra, A. Chen, M. Chernyakova, J. O. Chibueze, O. Chibueze, S. Colafrancesco, T. Collins, B. Cornejo, G. Cotter, J. Damascene Mbarubucyeye, J. de Assis Scarpin, M. de Bony de Lavergne, M. de Naurois, E. de Oña Wilhelmi, A. G. Delgado Giler, A. Djannati-Ataï, J. Djuvsland, A. Dmytriiev, R. Ebrahim, K. Egg, C. Escañuela Nieves, K. Feijen, M. D. Filipovic, G. Fontaine, S. Funk, S. Gabici, J. F. Glicenstein, J. Glombitza, P. Goswami, M. -H. Grondin, B. Hess, J. A. Hinton, T. L. Holch, M. Holler, D. Horns, M. Jamrozy, F. Jankowsky, I. Jung-Richardt, E. Kasai, K. Kasprzak, K. Katarzyński, D. Kerszberg, B. Khélifi, N. Komin, K. Kosack, D. Kostunin, R. G. Lang, S. Lazarević, V. Lefranc, J. -P. Lenain, P. Liniewicz, A. Luashvili, J. Mackey, D. Malyshev, D. Malyshev, V. Marandon, P. Marchegiani, M. Mayer, A. Mehta, A. M. W. Mitchell, R. Moderski, M. O. Moghadam, L. Mohrmann, E. Moulin, J. Niemiec, P. O'Brien, L. Olivera-Nieto, S. Panny, M. Panter, R. D. Parsons, U. Pensec, D. A. Prokhorov, G. Pühlhofer, M. Punch, A. Quirrenbach, M. Regeard, A. Reimer, O. Reimer, H. Ren, F. Rieger, B. Rudak, K. Sabri, V. Sahakian, H. Salzmann, M. Sasaki, F. Schüssler, J. N. S. Shapopi, W. Si Said, S. Spencer, Ł. Stawarz, S. Steinmassl, T. Tanaka, A. M. Taylor, R. Terrier, M. Tsirou, T. Unbehaun, C. van Eldik, M. Vecchi, C. Venter, J. Vink, T. Wach, A. Wierzcholska, A. Zech, W. Zhong

Abstract

Context: Composite galaxies that contain both Seyfert and starburst components may produce very high-energy (VHE; >100 GeV) gamma-ray emission at a wide range of spatial scales, from a few Schwarzschild radii of a supermassive black hole to dimensions of kiloparsec-size jet-driven outflows. In addition to supernova remnants, various sources have been suggested to explain data collected on composite galaxies, including multi-messenger neutrino and ultra-high-energy cosmic-ray data. Aims: The closest composite Seyfert-starburst galaxies (NGC 1068, the Circinus galaxy, and NGC 4945) are observed with the High Energy Stereoscopic System (H.E.S.S.) to provide constraints on cosmic-ray populations in these systems. Methods: Data obtained in H.E.S.S. observations have been analyzed to search for VHE gamma-ray counterparts to the GeV gamma-ray signals detected with Fermi-LAT and for potential spectral components in the VHE range. Results: No significant signals have been found in these H.E.S.S. data. Upper limits on the VHE gamma-ray fluxes were applied to constrain theoretical models involving different spectral components.

H.E.S.S. observations of composite Seyfert-starburst galaxies

Abstract

Context: Composite galaxies that contain both Seyfert and starburst components may produce very high-energy (VHE; >100 GeV) gamma-ray emission at a wide range of spatial scales, from a few Schwarzschild radii of a supermassive black hole to dimensions of kiloparsec-size jet-driven outflows. In addition to supernova remnants, various sources have been suggested to explain data collected on composite galaxies, including multi-messenger neutrino and ultra-high-energy cosmic-ray data. Aims: The closest composite Seyfert-starburst galaxies (NGC 1068, the Circinus galaxy, and NGC 4945) are observed with the High Energy Stereoscopic System (H.E.S.S.) to provide constraints on cosmic-ray populations in these systems. Methods: Data obtained in H.E.S.S. observations have been analyzed to search for VHE gamma-ray counterparts to the GeV gamma-ray signals detected with Fermi-LAT and for potential spectral components in the VHE range. Results: No significant signals have been found in these H.E.S.S. data. Upper limits on the VHE gamma-ray fluxes were applied to constrain theoretical models involving different spectral components.
Paper Structure (19 sections, 1 equation, 3 figures, 2 tables)

This paper contains 19 sections, 1 equation, 3 figures, 2 tables.

Table of Contents

  1. Introduction
  2. Composite galaxies as potential VHE sources
  3. Composite galaxies: NGC 1068, Circinus, and NGC 4945
  4. VHE flux expectations based on GeV emission
  5. H.E.S.S. observations and results
  6. H.E.S.S. experiment and analysis methods
  7. Observations, data analyses, and results
  8. NGC 1068
  9. Circinus galaxy
  10. NGC 4945
  11. Discussion
  12. VHE $\gamma$-ray emission due to AGN outflows
  13. Jet-driven bubbles: NGC 1068 and the Circinus galaxy
  14. Temporal and spectral characteristics of NGC 4945
  15. VHE neutrinos from the surroundings of a SMBH
  16. ...and 4 more sections

Figures (3)

  • Figure 1: Flux upper limits obtained from H.E.S.S. observations of NGC 1068. This figure also shows MAGIC flux upper limits ReferenceMAGIC along with a Fermi-LAT data bow tie and an 0.1-1 TeV data point from the Fermi-LAT catalog 4FGLDR3. Models A and B show the absorbed $\gamma$-ray flux from the neutrino source (see Sect. \ref{['sect_neutrino']}). A model for jet-driven bubbles (Sect. \ref{['bubbles']}) is provided. The calorimetric bound is also shown.
  • Figure 2: Flux upper limits from H.E.S.S. observations of the Circinus galaxy. This figure also shows a Fermi-LAT data bow tie and an 0.1-1 TeV data point from the Fermi-LAT catalog 4FGLDR3. A model involving gamma-ray emitting lobes is shown for different values of a spectral break.
  • Figure 3: Flux upper limits obtained from H.E.S.S. observations of NGC 4945. The calorimetric bound is from ReferenceWang; Models 1 and 2 are from ReferenceWojaczynski and ReferenceJiang, respectively.