Article
Astronomy & Astrophysics
A. Akylas, I Papadakis, A. Georgakakis
Summary: The study assesses X-ray flux variability as a tool for measuring black hole mass in active galactic nuclei, establishing a prescription for estimating BH masses based on normalized excess variance measurements. It finds that accurate BH mass measurements are possible with the right requirements in terms of light-curve duration and X-ray signal-to-noise ratio.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
M. Marzi, F. Tombesi, A. Luminari, K. Fukumura, D. Kazanas
Summary: This article investigates the properties of ionized plasma layers ejected from supermassive black holes and explores the impact of special relativistic corrections on their dynamics. The results demonstrate that the P-R effect plays an important role in determining the velocity profile of high-velocity, photoionized outflows.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
A. Moranchel-Basurto, F. J. Sanchez-Salcedo, Raul O. Chametla, P. F. Velazquez
Summary: Supernova explosions may affect the structure and evolution of circumnuclear disks in active galactic nuclei. The contribution of supernova explosions to effective alpha viscosity varies depending on the conditions, with simulations suggesting different outcomes under different scenarios.
ASTROPHYSICAL JOURNAL
(2021)
Article
Physics, Multidisciplinary
Jordy Davelaa, Zoltan Haiman
Summary: Supermassive black hole binaries can create self-lensing flares when the line of sight is aligned with the two black holes. If the binary orbit is nearly perpendicular to the line of sight, a distinctive feature can be observed in the light curve due to the relativistic shadow around the background black hole. Using ray tracing in a binary model, researchers predict that approximately 1% of current binary candidates could exhibit this feature. The proposed BH tomography method can extract spatially unresolvable black hole shadows using high-resolution very long baseline interferometry (VLBI).
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Samuele Campitiello, Annalisa Celotti, Gabriele Ghisellini, Tullia Sbarrato
Summary: The study investigates the luminosity ratio R between the torus and accretion disk for approximately 2000 luminosity-selected radio-quiet Type I active galactic nuclei. The mean R is around 0.8, with some sources having R greater than or close to 1. Statistical analysis suggests that the largest values of R may be linked to strong relativistic effects due to large black hole spin, despite the radio-quiet nature of the sources.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Andrew King, Rebecca Nealon
Summary: Recent research has found that the sample size of dwarf galaxies with measured central black hole masses and velocity dispersions has doubled, showing a close fit to the extrapolation of the M-sigma relation for more massive galaxies. This challenges the idea that the scaling relations between galaxies and their central black holes are merely a statistical consequence of assembly through repeated mergers. The prediction of significantly larger black hole masses in dwarf galaxies suggests an initial distribution of uncorrelated seed black hole and stellar masses confined to much smaller masses than previously assumed.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
P. Chainakun, I Fongkaew, S. Hancock, A. J. Young
Summary: Neural network models are developed in this study for predicting the black hole mass, and the accuracy of the predictions is found to be significantly higher compared to traditional linear regression methods. This suggests that neural network techniques are a promising and independent way to estimate the black hole mass. The study also investigates the global relations when the number of reverberating AGNs increases through simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Review
Physics, Particles & Fields
Tamara Bogdanovic, M. Coleman Miller, Laura Blecha
Summary: The next two decades are expected to witness the first simultaneous detection of electromagnetic and gravitational-wave signals from merging massive black-hole binaries. This breakthrough will revolutionize multimessenger astrophysics in the low-frequency gravitational-wave regime, providing unprecedented insights into the evolution of massive black holes and galaxies. It will also lead to novel cosmological probes and unique tests of gravity. This Living Review aims to introduce this research topic by summarizing key findings, physical processes, and ideas related to electromagnetic counterparts of massive black-hole mergers, as per the existing knowledge at the time of writing. It reviews the current observational evidence for close massive black-hole binaries, discusses relevant physical processes and timeframes, and presents possible electromagnetic counterparts during the precursor, coalescence, and afterglow stages of a massive black-hole merger. It also addresses open questions and discusses future prospects in this rapidly evolving research field.
LIVING REVIEWS IN RELATIVITY
(2022)
Article
Astronomy & Astrophysics
Elia Cenci, Luca Sala, Alessandro Lupi, Pedro R. Capelo, Massimo Dotti
Summary: This study implemented a self-consistent sub-grid model to simulate the evolution of black hole mass and spin at galactic nuclei, finding a close relationship between spin evolution and parameters related to gas accretion. Coupling the model with a feedback process significantly altered the evolution path of the black hole.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Shihong Liao, Peter H. Johansson, Matias Mannerkoski, Dimitrios Irodotou, Francesco Paolo Rizzuto, Stuart McAlpine, Antti Rantala, Alexander Rawlings, Till Sawala
Summary: We propose a new model to study the accretion and feedback of SMBH binaries, which allows us to investigate the evolution of SMBH binaries in gas-rich galaxy mergers. Our model includes preferential mass accretion on to the secondary SMBH and can resolve SMBH binaries down to separations of tens of Schwarzschild radii. We perform simulations of gas-rich disc galaxy mergers with different types of AGN feedback and find that the feedback implementation plays a critical role in the merger time-scales and the resulting stellar profiles.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jiachen Jiang, Askar B. Abdikamalov, Cosimo Bambi, Christopher S. Reynolds
Summary: We re-analyze the XMM-Newton and NuSTAR observing campaigns for the well-studied, X-ray-bright AGN MCG-06-30-15, considering a disc model with finite thickness. By fitting the disc reflection spectra in the data, we find a black hole spin of 0.87-0.99, which is consistent with previous measurements based on razor-thin disc models. Additionally, we assume an isotropic, point-like geometry for the corona, and find that such a geometry overestimates the disc reflection fraction parameter. Thin disc models with a free reflection fraction parameter provide a better fit when considering the disc thickness.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Raj, C. J. Nixon
Summary: Accretion disks around black holes can become warped and unstable, leading to a dynamic and variable accretion flow. Recent studies have shown that strongly warped disks may break into discrete rings, causing observable fluctuations in the accretion process.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
G. A. Matzeu, M. Brusa, G. Lanzuisi, M. Dadina, S. Bianchi, G. Kriss, M. Mehdipour, E. Nardini, G. Chartas, R. Middei, E. Piconcelli, V. Gianolli, A. Comastri, A. L. Longinotti, Y. Krongold, F. Ricci, P. O. Petrucci, F. Tombesi, A. Luminari, L. Zappacosta, G. Miniutti, M. Gaspari, E. Behar, M. Bischetti, S. Mathur, M. Perna, M. Giustini, P. Grandi, E. Torresi, C. Vignali, G. Bruni, M. Cappi, E. Costantini, G. Cresci, B. De Marco, A. De Rosa, R. Gilli, M. Guainazzi, J. Kaastra, S. Kraemer, F. La Franca, A. Marconi, F. Panessa, G. Ponti, D. Proga, F. Ursini, P. Baldini, F. Fiore, A. R. King, R. Maiolino, G. Matt, A. Merloni
Summary: We present a new X-ray spectroscopic study of 22 luminous AGNs at intermediate redshifts, focusing on the search for and characterization of ultra-fast outflows (UFOs). Through Monte Carlo procedures, we confirm the detection of highly ionized iron absorption lines in 7 out of 22 sources at a high confidence level, supporting the existence of highly ionized matter propagating at mildly relativistic speeds in a considerable fraction of AGNs. The SUpermassive Black hole Winds in the x-rAYS (SUBWAYS) campaign extends previous studies on Seyferts and finds a UFO detection fraction of approximately 30% of the total sample.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
F. H. Vincent, M. Wielgus, M. A. Abramowicz, E. Gourgoulhon, J-P Lasota, T. Paumard, G. Perrin
Summary: Researchers aim to develop a simple analytic disk model for the accretion flow of M87* to predict its image, assuming it is a Kerr black hole or an alternative compact object. They computed synchrotron emission from the disk model and carried out numerical fits to the EHT data, showing that alternatives to the Kerr spacetime may provide similar results and further observations are needed to test the Kerr paradigm conclusively.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
L. Piro, M. Colpi, J. Aird, A. Mangiagli, A. C. Fabian, M. Guainazzi, S. Marsat, A. Sesana, P. McNamara, M. Bonetti, E. M. Rossi, N. R. Tanvir, J. G. Baker, G. Belanger, T. Dal Canton, O. Jennrich, M. L. Katz, N. Luetzgendorf
Summary: The European Space Agency is studying two large-class missions in the 2030s to investigate energetic and violent phenomena in the Universe. The Athena mission aims to study baryons in large-scale structures and accreting supermassive black holes, while LISA mission extends the hunt for gravitational wave events. The concurrent operation of these missions can enable unique experiments in astrophysics and cosmography.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Ioannis Myserlis, Ioannis Contopoulos
Summary: The study found large-scale magnetic fields in 16 out of 35 nearby edge-on spiral galaxies by analyzing radio halos. The rotation measure maps showed a universal toroidal magnetic field pattern in the halo above and below the disk of the galaxy, indicating a possible origin from the central supermassive black hole's accretion disk.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
D. J. K. Buisson, D. Altamirano, M. Armas Padilla, Z. Arzoumanian, P. Bult, N. Castro Segura, P. A. Charles, N. Degenaar, M. Diaz Trigo, J. van den Eijnden, F. Fogantini, P. Gandhi, K. Gendreau, J. Hare, J. Homan, C. Knigge, C. Malacaria, M. Mendez, T. Munoz Darias, M. Ng, M. Ozbey Arabaci, R. Remillard, T. E. Strohmayer, F. Tombesi, J. A. Tomsick, F. Vincentelli, D. J. Walton
Summary: The study uncovers eclipses in the X-ray light curves of the X-ray binary Swift J1858.6-0814, revealing the orbital period and eclipse duration. Additionally, absorption dips were observed during the pre-eclipse phase, and bright flares were found to occur preferentially in the post-eclipse phase of the orbit.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Review
Oncology
Matteo Santoni, Francesco Tombesi, Alessia Cimadamore, Rodolfo Montironi, Francesco Piva
Summary: It is crucial to adopt three physically-motivated scales (micro - meso - macro) for achieving a unified theory of multiphase active galactic nuclei feeding and feedback, which will be key for astrophysical simulations and observations in the coming years. To promote the multi-scale idea, an interdisciplinary approach is being taken to explore conceptual similarities between supermassive black hole feeding and feedback cycles and dynamics in human cancer microenvironments.
FRONTIERS IN ONCOLOGY
(2021)
Article
Astronomy & Astrophysics
A. Ratheesh, G. Matt, F. Tombesi, P. Soffitta, M. Pesce-Rollins, A. Di Marco
Summary: This study aims to use X-ray spectro-polarimetry to derive the geometrical properties of absorbing and reflecting matter, with parameters derived from NuSTAR data through hard X-ray spectroscopy. The results suggest that X-ray polarimetric observations can help determine geometrical parameters left unconstrained by spectroscopic analysis.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
A. Mei, F. Tombesi
Summary: The study investigates the differences between radio-loud and radio-quiet active galactic nuclei, focusing on the inner components of the broad line radio galaxy 3C 215. It reveals high accretion rates and complex jet emission in the galaxy, potentially indicating a sub-parsec SMBH binary system, although further analysis is needed for confirmation.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. Zanchettin, C. Feruglio, M. Bischetti, A. Malizia, M. Molina, A. Bongiorno, M. Dadina, C. Gruppioni, E. Piconcelli, F. Tombesi, A. Travascio, F. Fiore
Summary: The analysis of the ALMA CO(2 1) emission line and 1.2mm continuum of Mrk 509 reveals the presence of a molecular gas reservoir within a disc, ongoing star formation in a starburst ring, and indications of a minor merger. This suggests that galaxy mergers can lead to gas destabilization, fueling both star formation and AGN activity.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
R. Serafinelli, V Braito, P. Severgnini, F. Tombesi, G. Giani, E. Piconcelli, R. Della Ceca, F. Vagnetti, M. Gaspari, F. G. Saturni, R. Middei, A. Tortosa
Summary: The study analyzed photoionized absorbers of outflowing gas in the X-ray spectra of active galactic nuclei, finding variable ionized obscurers, a fully covering absorber with significantly higher column density compared to previous observations, and an estimated minimum distance of an ionized clump located at r greater than or similar to 0.5 pc. These variations in column density could be due to changes in known absorbers or the presence of a new one that eclipses the X-ray emitting source.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Sudip Chakraborty, Ajay Ratheesh, Sudip Bhattacharyya, John A. Tomsick, Francesco Tombesi, Keigo Fukumura, Gaurava K. Jaisawal
Summary: The study analyzed the broad-band spectral of all six NuSTAR observations of MAXI J1348-630 during its first outburst in 2019, finding that a simple model scheme was inadequate and exploring the possibility of high-density disc reflection using two different sets of models. The REFLIONX-based high-density disc reflection models lowered the iron abundance to around the solar value, with evidence of high-velocity outflow. Consistency in best-fitting parameters for different epochs and statistical significance of the model indicated the presence of high-density disc reflection in MAXI J1348-630.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. Laurenti, E. Piconcelli, L. Zappacosta, F. Tombesi, C. Vignali, S. Bianchi, P. Marziani, F. Vagnetti, A. Bongiorno, M. Bischetti, A. del Olmo, G. Lanzuisi, A. Luminari, R. Middei, M. Perri, C. Ricci, G. Vietri
Summary: In this study, the X-ray spectral analysis of 14 high-Eddington-ratio AGN reveals that despite the homogeneous optical and supermassive black hole accretion properties, the X-ray properties of these AGN are quite heterogeneous. Interestingly, some sources exhibit much fainter X-ray emission compared to typical AGN.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Aysegul Tumer, Daniel R. Wik, Massimo Gaspari, Hiroki Akamatsu, Niels J. Westergaard, Francesco Tombesi, E. Nihal Ercan
Summary: This study investigates the interaction between galaxy clusters and cosmic filaments using NuSTAR, XMM-Newton, and Suzaku data. The results indicate that the interface between the cluster and the intercluster filament does not show signs of heated plasma, but rather has low temperature, high density, and low entropy, suggesting gas cooling. Furthermore, the temperature analysis using different data sources is consistent.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Dimitris M. Christodoulou, Silas G. T. Laycock, Demosthenes Kazanas, Ioannis Contopoulos
Summary: Studies have shown that variations in the magnetic fields of the X-ray binaries Her X-1 and A 0535+26 lead to changes in CRSFs, while the magnetic dipoles reaching out to the accretion discs remain largely unchanged.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. Marzi, F. Tombesi, A. Luminari, K. Fukumura, D. Kazanas
Summary: This article investigates the properties of ionized plasma layers ejected from supermassive black holes and explores the impact of special relativistic corrections on their dynamics. The results demonstrate that the P-R effect plays an important role in determining the velocity profile of high-velocity, photoionized outflows.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Ioannis Contopoulos, Athanasios C. Tzemos, Foivos Zanias, George Contopoulos
Summary: This paper demonstrates how a classical detector that collects non-interacting individual classical massive free particles can generate a quantum interference pattern. The proposed classical picture requires that particles carry the information of a phase equal to an action integral along their trajectory. An interference pattern is gradually built from the collection of particle phases in the detection bins of the detector after several repetitions of the experiment. The main conclusion of the present work is that the interference of quantum mechanics is basically due to the detectors that collect the particles when there are macroscopic detectors operating as proposed.
Article
Astronomy & Astrophysics
Ioannis Contopoulos, Ioannis Myserlis, Demosthenes Kazanas, Antonios Nathanail
Summary: The Cosmic Battery plays a crucial role in determining the direction of the axial magnetic field, but difficulties exist in RM measurements of M87* at scale, requiring long-term monitoring and a synergy of lower resolution RM observations for validation.
Article
Astronomy & Astrophysics
L. Barchiesi, F. Pozzi, C. Vignali, F. J. Carrera, F. Vito, F. Calura, L. Bisigello, G. Lanzuisi, C. Gruppioni, E. Lusso, I. Delvecchio, M. Negrello, A. Cooray, A. Feltre, J. A. Fernandez-Ontiveros, S. Gallerani, H. Kaneda, S. Oyabu, M. Pereira-Santaella, E. Piconcelli, C. Ricci, G. Rodighiero, L. Spinoglio, F. Tombesi
Summary: The study reveals that in the framework of black hole-galaxy co-evolution, most of the star formation and black hole accretion are expected to occur in highly obscured conditions, making it difficult to detect obscured active galactic nuclei in optical or X-ray bands. Through investigating the synergies between infrared missions and X-ray missions, it is found that Athena can detect and characterize AGN, especially the most obscured ones.
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA
(2021)