Results 81 to 90 of about 2,057,503 (206)

Non-linearly scalarized supermassive black holes

open access: yesEuropean Physical Journal C: Particles and Fields
In this study, we investigate a nonlinear mechanism driving the formation of scalarized rotating black holes within a scalar-Gauss–Bonnet gravity framework that includes an additional squared Gauss–Bonnet term.
Shoupan Liu   +3 more
doaj   +1 more source

Interplay of Magnetic Reconnection and Current Sheet Kink Instability in the Earth's Magnetotail

open access: yesGeophysical Research Letters, Volume 52, Issue 2, 28 January 2025.
Abstract Magnetic reconnection and current sheet kink instability often develop concurrently in current sheets, yet their dynamic interplay remains unclear. We investigate their interaction in the magnetotail of a 3D global magnetospheric hybrid‐Vlasov simulation. We identify the instability growth and saturation phase and estimate the evolution of the
G. Cozzani   +12 more
wiley   +1 more source

On the location of the supermassive black hole in CTA 102 [PDF]

open access: yesAstronomy & Astrophysics, 2015
Relativistic jets in active galactic nuclei represent one of the most powerful phenomena in the Universe. They form in the surroundings of the supermassive black holes as a by-product of accretion onto the central black hole in active galaxies. The flow in the jets propagates at velocities close to the speed of light.
Fromm, Christian M.   +4 more
openaire   +5 more sources

Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers

open access: yesAstronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto   +9 more
wiley   +1 more source

A NORMAL SUPERMASSIVE BLACK HOLE IN NGC 1277 [PDF]

open access: yesThe Astrophysical Journal, 2016
ABSTRACT The identification of galaxies with “overly massive” black holes requires two measurements: a black hole mass (M bh) and a host spheroid mass ( ). Here we provide our measurements for NGC 1277.
Alister W. Graham   +7 more
openaire   +5 more sources

Asymptotically‐Flat Black Hole Solutions in Symmergent Gravity

open access: yesFortschritte der Physik, Volume 72, Issue 4, April 2024.
Abstract Symmergent gravity is an emergent gravity model with an R+R2$R+R^2$ curvature sector and an extended particle sector having new particles beyond the known ones. With constant scalar curvature, asymptotically flat black hole solutions are known to have no sensitivity to the quadratic curvature term (coefficient of R2$R^2$). With variable scalar
Beyhan Puliçe   +3 more
wiley   +1 more source

Differential rotation in compact objects with hyperons and delta isobars

open access: yesAstronomische Nachrichten, Volume 345, Issue 2-3, February-March 2024.
Abstract Neutron stars may experience differential rotation on short, dynamical timescales following extreme astrophysical events like binary neutron star mergers. In this work, the masses and radii of differentially rotating neutron star models are computed.
Delaney Farrell   +3 more
wiley   +1 more source

The Cosmic History of Black Hole Growth from Deep Multiwavelength Surveys

open access: yesAdvances in Astronomy, 2012
Significant progress has been made in the last few years on understanding how supermassive black holes form and grow. In this paper, we begin by reviewing the spectral signatures of active galactic nuclei (AGN) ranging from radio to hard X-ray ...
Ezequiel Treister, C. Megan Urry
doaj   +1 more source

Constraints on alternatives to supermassive black holes [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society: Letters, 2006
Abstract Observations of the centres of galaxies continue to evolve, and it is useful to take a fresh look at the constraints that exist on alternatives to supermassive black holes at their centres. We discuss constraints complementary to those of Maoz and demonstrate that an extremely wide range of other possibilities can be excluded ...
openaire   +2 more sources

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