6 papers
Constraints on the Gas Geometry Surrounding Little Red Dots through Narrow-Line Diagnostics
Visal Sok, Erica J. Nelson, Mitchell C. Begelman +10
Little Red Dots (LRDs) are a recently identified population of high-redshift sources, with a common interpretation being accreting black holes embedded within a spherical, opticall…
Electron-positron Pair Production in Global GRMHD Simulations of Black Hole Accretion Flows
Ho-Sang Chan, Jason Dexter, Mitchell C. Begelman
We present global, three-dimensional general relativistic magnetohydrodynamic simulations of accreting black holes that incorporate pair physics. Pairs are modeled as a passive sca…
Pulsational Instability of Quasi-Stars: Interpreting the Variability of Little Red Dots
Matteo Cantiello, Jake B. Hassan, Rosalba Perna +5
The JWST discovery of "Little Red Dots" (LRDs) has revealed a population of compact, red sources at that likely host supermassive black holes (SMBHs). Recent observat…
Little Red Dots As Late-stage Quasi-stars
Mitchell C. Begelman, Jason Dexter
We argue that the "Little Red Dots" (LRDs) discovered with the James Webb Space Telescope are quasi-stars in their late stages of evolution. Quasi-stars are hypothetical objects pr…
The Growth of the Central Black Holes in Quasi-stars
Jake Hassan, Rosalba Perna, Matteo Cantiello +3
Observations by JWST have confirmed the presence of supermassive black holes (BHs) at redshifts , lending support to scenarios in which BHs experience rapid growth thro…
Energy Diffusion and Advection Coefficients in Kinetic Simulations of Relativistic Plasma Turbulence
Kai W. Wong, Vladimir Zhdankin, Dmitri A. Uzdensky +2
Turbulent, relativistic nonthermal plasmas are ubiquitous in high-energy astrophysical systems, as inferred from broadband nonthermal emission spectra. The underlying turbulent non…