Related papers: Accretion Stream Mapping
The axion dark matter echo technique, proposed in Ref. [1], aims to search for axion dark matter by detecting the electromagnetic echo coming from stimulated decay of ambient axion dark matter interacting with a radio-microwave outgoing…
The boundary layers of weakly-magnetized white dwarfs (WDs) accreting at rates <=10^16 g/s are radially extended, hot, optically-thin, and they advect some of their internally-dissipated energy (Narayan & Popham 1993). Motivated by this, I…
A fundamental assumption adopted in nearly every extragalactic emission-line study is that the attenuation of different emission lines can be described by a single attenuation curve. Here we show this assumption fails in many cases with…
The Event Horizon Telescope (EHT), now with its first ever image of the photon ring around the supermassive black hole of M87, provides a unique opportunity to probe the physics of supermassive black holes through Very Long Baseline…
In intensity-modulated radiation therapy, optimal intensity distributions of incoming beams are decomposed into linear combinations of leaf openings of a multileaf collimator (segments). In order to avoid inefficient dose delivery, the…
Double peaked broad emission lines in active galactic nuclei are generally considered to be formed in an accretion disc. In this paper, we compute the profiles of reprocessing emission lines from a relativistic, warped accretion disc around…
We calculate the flux and spectrum of \gamma-rays emitted by a two-temperature advection-dominated accretion flow (ADAF) around a black hole. The \gamma-rays are from the decay of neutral pions produced through proton-proton collisions. We…
One of the most useful spectral diagnostics of accreting black hole systems is the Fe K$\alpha$ fluorescence line. Detected in many systems, it is often used to estimate the black hole spin, as its breadth is attributed to relativistic…
We present a computational framework for simulating filamentary electric discharges, in which channels are represented as conducting cylindrical segments. The framework requires a model that predicts the position, radius, and line…
Strongly interacting electrons in clean two-dimensional devices are theorized to exhibit many distinct transport regimes, such as ballistic, hydrodynamic, or diffusive. Realistic samples often lie in crossover regimes between these…
The positions and velocities of stellar streams have been used to constrain the mass and shape of the Milky Way's dark matter halo. Several extragalactic streams have already been detected, though it has remained unclear what can be…
A detailed experimental and simulation study of the extraction of a 24 keV He-ion beam from an ECR ion source and the subsequent beam transport through an analyzing magnet is presented. We find that such a slow ion beam is very sensitive to…
We examine a new family of global analytic solutions for optically thick accretion disks, which includes the supercritical accretion regime. We found that the ratio of the advection cooling rate, $Q_{\rm adv}$, to the viscous heating rate,…
In this fluid dynamics video, results from high fidelity numerical simulations are presented, which have been carried out to study the flow and droplet dynamics of liquid sheets formed by two impinging jets. A three-dimensional…
Numerical simulation of magnetohydrodynamic (MHD) turbulence makes it possible to study accretion dynamics in detail. However, special effort is required to connect inflow dynamics (dependent largely on angular momentum transport) to…
We present high-resolution, phase-resolved spectroscopic observations of the polar EF Eri, obtained with SALT and the SAAO 1.9-m telescope during its recent emergence from a three-decade-long low state. The average spectrum shows strong…
This work introduces a novel adaptive mesh refinement (AMR) method that utilizes dominant balance analysis (DBA) for efficient and accurate grid adaptation in computational fluid dynamics (CFD) simulations. The proposed method leverages a…
It is well known that closed-form analytical solutions for AC power flow equations do not exist in general. This paper proposes a multi-dimensional holomorphic embedding method (MDHEM) to obtain an explicit approximate analytical AC…
We present an experimental platform for measuring hydrogen Balmer emission and absorption line profiles for plasmas with white dwarf (WD) photospheric conditions (T_e ~ 1 eV, n_e ~ 10^17 cm^-3). These profiles will be used to benchmark WD…
We develop a reduced-order framework for optimizing mixing in two-dimensional incompressible flows. Instead of optimizing the full transport PDE, the method maximizes the length of advected material interfaces, leading to a…