Search

We revisit the spectral appearance of extended self-gravitating accretion disks surrounding compact central objects such as supermassive black holes. Using dust-poor opacities, we show that all …

Several local (\(z\lesssim 0.2\)) metal-poor dwarf AGNs have remarkably similar properties to those of high-redshift Little Red Dots (LRDs), and are recently proposed to …

The formation of a compact accretion disk following a tidal disruption event (TDE) requires that the shocked stellar debris cool efficiently as it settles toward the black hole …

We present a comprehensive analysis of super-Eddington black hole accretion simulations that solve the GRMHD equations coupled with angle-discretized radiation transport. The simulations span a range …

The JWST discovery of "Little Red Dots" (LRDs) has revealed a population of compact, red sources at \(z \sim 5-10\) that likely host supermassive black holes (SMBHs …

We present the first 3D Radiation-Hydrodynamics simulations of partially-stripped (\(M_\mathrm{core}\sim10M_\odot\), \(M_\mathrm{env}\sim0.1-1M_\odot\)) Yellow Supergiant ( …

Little red dots (LRDs), high-redshift, compact, red objects with V-shaped spectra, are one of the most exciting and perplexing discoveries made by the James Webb Space …

The early time emission in tidal disruption events (TDEs) originates from both accretion and shocks, which produce photons that eventually emerge from an inhomogeneous photosphere. In this work …

Superthermal gas giant planets or their progenitor cores are known to open deep gaps in protoplanetary disks, which stop large, drifting dust particles on their way to the …

We summarize results from a survey of radiation-dominated black hole accretion flows across a wide range of mass accretion rates, as well as two values of black …

Radiative cooling can drive dynamics in multi-phase gas. A dramatic example is hydrodynamic `shattering', the violent, pressure-driven fragmentation of a cooling cloud which falls drastically out …

The physical origin of Little Red Dots (LRDs)--compact extragalactic sources with red rest-optical continua and broad Balmer lines--remains elusive. The redness of LRDs is likely …

We perform two-dimensional, multi-group radiation hydrodynamic simulations to explore the observational properties of a solar-like star colliding with an accretion disk around a supermassive black …

We perform 3D radiation-magnetohydrodynamic simulations of the evolution of the fallback debris after a tidal disruption event (TDE). We focus on studying the effects of magnetic fields …

We review our current knowledge of thermal and viscous instabilities in accretion discs around compact objects. We begin with classical disc models based on analytic viscosity prescriptions, discussing …

We present Denario, an AI multi-agent system designed to serve as a scientific research assistant. Denario can perform many different tasks, such as generating ideas, checking the …

We present a global three-dimensional radiation magnetohydrodynamic (RMHD) simulation of a circumbinary disk (CBD) around a massive black hole binary (MBHB) with a total mass …

Recent observations have revealed slow, coherent temperature fluctuations in AGN disks that propagate both inward and outward at velocities of ∼0.01–0.1c, a kind of variability …

A variety of physical processes leads to the low-energy ejection of material from the hydrogen-rich envelopes of red and yellow supergiants. These include common envelope events …

We are on the cusp of detecting gravitational waves (GWs) from individual massive black hole binaries (MBHBs) with the Laser Interferometer Space Antenna and pulsar timing arrays. These …

Accretion discs in Active Galactic Nuclei (AGNs) are predicted to become gravitationally unstable substantially interior to the black hole's sphere of influence, at radii where the disc …

A range of stellar explosions, including supernovae (SNe), tidal disruption events (TDE), and fast blue optical transients (FBOTs), can occur in dusty environments initially opaque to transients' optical …

We present the results of four 3D radiation magnetohydrodynamic simulations of accretion disks around a 10\(^{8}\) solar mass black hole, which produce the far-ultraviolet spectrum peak …

Massive stars can form within or be captured by active galactic nucleus disks, influencing both the thermal structure and metallicity of the disk environment. In a previous work …

We investigate how the formation and structure of circumplanetary disks (CPDs) vary with planet mass and protoplanetary disk aspect ratio. Using static mesh refinement and a near-isothermal …

We present the first three-dimensional radiation magnetohydrodynamic (RMHD) simulation of a sub-Eddington circumbinary disk (CBD) around an equal-mass massive black hole binary with a total …

Spiral perturbations in a gravitationally unstable accretion disk regulate disk evolution through angular momentum transport and heating and provide an observational signature of gravitational instability (GI). We use …

Fragmentation in a gravitationally unstable accretion disk can be an important pathway for forming stellar/planetary companions. To characterize quantitatively the condition for and outcome of fragmentation under …

We conduct a parameter survey of neutron star accretion column simulations by solving the relativistic radiation MHD equations with opacities that account for strong magnetic fields and pair …

Disk continuum reverberation mapping is one of the primary ways we learn about active galactic nuclei (AGN) accretion disks. Reverberation mapping assumes that time-varying X-rays incident …

When a star passes through the tidal disruption radius of a massive black hole (BH), it can be torn apart by the tidal force of the BH, known …

We present the results of four magnetohydrodynamic simulations and one alpha-disk simulation of accretion disks in a compact binary system, neglecting vertical stratification and assuming a locally …

Machine learning based surrogate models offer researchers powerful tools for accelerating simulation-based workflows. However, as standard datasets in this space often cover small classes of physical behavior …

We use Athena++ to study the hydrodynamics of repeated star‑accretion disk collisions close to supermassive black holes, and we discuss their implications for the origin of quasi …

Quasar feedback is a key ingredient in shaping galaxy evolution. A rare population of extremely red quasars (ERQs) at \(z=2-3\) are often associated with high-velocity …

Massive stars may form in or be captured into AGN disks. Recent 1D studies employing stellar-evolution codes have demonstrated the potential for rapid growth of such stars …

The rising part of a tidal disruption event light curve provides unique insight into early emission and the onset of accretion. Various mechanisms are proposed to explain the …

We use the Athena++ Monte Carlo (MC) radiation transfer module to post-process simulation snapshots from non-relativistic Athena++ radiation magnetohydrodynamic (RMHD) simulations. These simulations were run using …

In this chapter, we summarize recent progress on the properties of accretion disks when the accretion rate exceeds the so-called Eddington limit based on multi-dimensional radiation …

It is well established that supermassive black hole (SMBH) feedback is crucial for regulating the evolution of massive, if not all, galaxies. However, modelling the interplay between SMBHs …

Turbulence is crucial for protoplanetary disk dynamics, and Vertical Shear Instability (VSI) is a promising mechanism in outer disk regions to generate turbulence. We use Athena++ radiation module …

We use local stratified shearing-box simulations with magnetic field-aligned thermal conduction to study an idealized model of the coupling between a cold, radiatively efficient accretion disc …

Active galactic nuclei (AGN) light curves observed with different wave bands show that the variability in longer wavelength bands lags the variability in shorter wavelength bands. Measuring these …

We investigate the dynamical interaction between cosmic rays (CRs) and the multiphase interstellar medium (ISM) using numerical magnetohydrodynamic (MHD) simulations with a two-moment CR solver and TIGRESS …

Gas giant planets are expected to accrete most of their mass via a circumplanetary disk. If the planet is unmagnetized and initially slowly rotating, it will accrete gas …

Gas giant planets are expected to accrete most of their mass via a circumplanetary disk. If the planet is unmagnetized and initially slowly rotating, it will accrete gas …

Accretion disks around supermassive black holes in active galactic nuclei produce continuum radiation at ultraviolet and optical wavelengths. Physical processes in the accretion flow lead to stochastic variability …

We describe a new algorithm to solve the time dependent, frequency integrated radiation transport (RT) equation implicitly, which is coupled to an explicit solver for equations of magnetohydrodynamics …