Millimeter emission from supermassive black hole coronae
Artikel i vetenskaplig tidskrift, 2025
Context. Active galactic nuclei (AGNs) host accreting supermassive black holes (SMBHs). The accretion process can lead to the formation of a hot, X-ray emitting corona close to the SMBH that can accelerate relativistic electrons. Observations in the millimeter band can probe its synchrotron emission. Aims. We intend to provide a framework to derive physical information of SMBH coronae by modelling their spectral energy distribution (SED) from radio to far-infrared frequencies. We also explore the possibilities of deriving additional information from millimeter observations, such as the SMBH mass, and studying high-redshift lensed sources. Methods. We introduce a corona emission model based on a one-zone spherical region with a hybrid thermal and non-thermal plasma. We investigated the dependence of the corona SED on different parameters such as size, opacity, and magnetic field strength. Other galactic emission components from dust, ionised gas, and diffuse relativistic electrons were also included in the SED fitting scheme. We applied our code consistently to a sample of radio-quiet AGNs with strong indications of a coronal component in the millimeter. Results. The detected millimeter emission from SMBH coronae is consistent with a non-thermal relativistic particle population with an energy density that is -0.5-10% of that in the thermal plasma. This requires magnetic energy densities close to equipartition with the thermal gas and corona sizes of 60-250 gravitational radii. The model can also reproduce the observed correlation between millimeter emission and SMBH mass when we accounted for the uncertainties in the corona size. Conclusions. The millimeter band offers a unique window into the physics of SMBH coronae, enabling the study of highly dust-obscured sources and high-redshift lensed quasars. Gaining a deeper understanding of the relativistic particle population in SMBH coronae can provide key insights into their potential multiwavelength and neutrino emission.
Galaxies: nuclei
Radio continuum: galaxies
Submillimeter: galaxies
Radiation mechanisms: non-thermal
Författare
Santiago Del Palacio
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Chentao Yang
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Susanne Aalto
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
C. Ricci
Universidad Diego Portales
Beijing University of Technology
Boy Lankhaar
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Sabine König
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Julia Tjus
Ruhr-Universität Bochum
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
M. Magno
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
Texas A&M University
Krista L. Smith
Texas A&M University
Jun Yang
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Loreto Barcos-Munoz
University of Virginia
National Radio Astronomy Observatory
F. Combes
Observatoire de Paris
S. T. Linden
University of Arizona
C. Henkel
Xinjiang Astronomical Observatory
Max-Planck-Gesellschaft
J. G. Mangum
National Radio Astronomy Observatory
S. Martin
Atacama Large Millimeter-submillimeter Array (ALMA)
European Southern Observatory Santiago
Gustav Olander
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
G. Privon
National Radio Astronomy Observatory
Clare Wethers
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Anne-Kathrin Baczko
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
R. J. Beswick
University of Manchester
I. García-Bernete
Centro de Astrobiologia (CAB)
S. G. Burillo
Observatorio Astronómico Nacional (OAN)
E. Gonzalez-Alfonso
Consejo Superior de Investigaciones Científicas (CSIC)
Mark Gorski
Northwestern University
M. Imanishi
National Astronomical Observatory of Japan
T. Izumi
National Astronomical Observatory of Japan
Sebastien Muller
Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium
Y. Nishimura
University of Tokyo
M. Pereira-Santaella
Consejo Superior de Investigaciones Científicas (CSIC)
P. van der Werf
Universiteit Leiden
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 701 A41Ämneskategorier (SSIF 2025)
Atom- och molekylfysik och optik
Fusion, plasma och rymdfysik
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202554936