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.
Cite
@article{arxiv.2603.21912,
title = {H.E.S.S. observations of composite Seyfert-starburst galaxies},
author = {H. E. S. S. Collaboration and A. Acharyya and F. Aharonian and H. Ashkar and M. Backes and V. Barbosa Martins and R. Batzofin and Y. Becherini and D. Berge and M. Böttcher and C. Boisson and J. Bolmont and J. Borowska and F. Brun and B. Bruno and C. Burger-Scheidlin and S. Casanova and J. Celic and M. Cerruti and S. Chandra and A. Chen and M. Chernyakova and J. O. Chibueze and O. Chibueze and S. Colafrancesco and T. Collins and B. Cornejo and G. Cotter and J. Damascene Mbarubucyeye and J. de Assis Scarpin and M. de Bony de Lavergne and M. de Naurois and E. de Oña Wilhelmi and A. G. Delgado Giler and A. Djannati-Ataï and J. Djuvsland and A. Dmytriiev and R. Ebrahim and K. Egg and C. Escañuela Nieves and K. Feijen and M. D. Filipovic and G. Fontaine and S. Funk and S. Gabici and J. F. Glicenstein and J. Glombitza and P. Goswami and M. -H. Grondin and B. Hess and J. A. Hinton and T. L. Holch and M. Holler and D. Horns and M. Jamrozy and F. Jankowsky and I. Jung-Richardt and E. Kasai and K. Kasprzak and K. Katarzyński and D. Kerszberg and B. Khélifi and N. Komin and K. Kosack and D. Kostunin and R. G. Lang and S. Lazarević and V. Lefranc and J. -P. Lenain and P. Liniewicz and A. Luashvili and J. Mackey and D. Malyshev and D. Malyshev and V. Marandon and P. Marchegiani and M. Mayer and A. Mehta and A. M. W. Mitchell and R. Moderski and M. O. Moghadam and L. Mohrmann and E. Moulin and J. Niemiec and P. O'Brien and L. Olivera-Nieto and S. Panny and M. Panter and R. D. Parsons and U. Pensec and D. A. Prokhorov and G. Pühlhofer and M. Punch and A. Quirrenbach and M. Regeard and A. Reimer and O. Reimer and H. Ren and F. Rieger and B. Rudak and K. Sabri and V. Sahakian and H. Salzmann and M. Sasaki and F. Schüssler and J. N. S. Shapopi and W. Si Said and S. Spencer and Ł. Stawarz and S. Steinmassl and T. Tanaka and A. M. Taylor and R. Terrier and M. Tsirou and T. Unbehaun and C. van Eldik and M. Vecchi and C. Venter and J. Vink and T. Wach and A. Wierzcholska and A. Zech and W. Zhong},
journal= {arXiv preprint arXiv:2603.21912},
year = {2026}
}
Comments
Accepted for publication in Astronomy and Astrophysics