Christopher S. Reynolds

TL;DR: In this paper, an advection-dominated model for the nucleus of M87 was examined and it was shown that accretion at the Bondi rate is compatible with the best known estimates for the core flux from radio through to X-ray wavelengths.

TL;DR: In this article, the authors identify the presence of large-scale low-frequency dynamo cycles in a long-duration, global, magnetohydrodynamic (MHD) simulation of black hole accretion.

Abstract: We report on a 151 ks net exposure Suzaku observation of the Narrow Line Seyfert 1 galaxy Mrk 335. The 0.5-40 keV spectrum contains a broad Fe line, a strong soft excess below about 2 keV and a Compton hump around 20-30 keV. We find that a model consisting of a power law and two reflectors provides the best fit to the time-averaged spectrum. In this model, an ionized, heavily blurred, inner reflector produces most of the soft excess, while an almost neutral outer reflector (outside ~40 r_g) produces most of the Fe line emission. The spectral variability of the observation is characterised by spectral hardening at very low count rates. In terms of our power-law + two-reflector model it seems like this hardening is mainly caused by pivoting of the power law. The rms spectrum of the entire observation has the curved shape commonly observed in AGN, although the shape is significantly flatter when an interval which does not contain any deep dip in the lightcurve is considered. We also examine a previous 133 ks XMM-Newton observation of Mrk 335. We find that the XMM-Newton spectrum can be fitted with a similar two-reflector model as the Suzaku data and we confirm that the rms spectrum of the observation is flat. The flat rms spectra, as well as the high-energy data from the Suzaku PIN detector, disfavour an absorption origin for the soft excess in Mrk 335.

TL;DR: The physics of weakly collisional, high-beta plasmas are studied in this article, where the thermal pressure dominates over the magnetic pressure and the interparticle collision time is comparable to the characteristic timescales of bulk motions.

TL;DR: In this paper, a relativistic ray tracing suite (Fenrir) was used to examine the effects that disk thickness may have on the reflection spectrum, including a truncation of the blue wing (from self-shadowing of the accretion disk) and an enhancement of the red wing ( from the irradiation of the central 'eye wall' of the inner disk).