We have carried out fully relativistic numerical simulations of accretion disks in the Kerr metric. In this paper we focus on unbound outflows that emerge self-consistently from flow. These are found axial funnel region and consist two components: a hot, fast, tenuous outflow proper colder, slower, denser jet along wall. The funnel-wall is excluded by elevated angular momentum also pressure-confined magnetized corona. Inside funnel, large-scale poloidal magnetic field spontaneously arises...

When the accretion rate is more than a small fraction of Eddington, inner regions disks around black holes are expected to be radiation dominated. However, in α-model, these also thermally unstable. In this paper, we report two three-dimensional magnetohydrodynamic simulations vertically stratified shearing box which ratio gas pressure ∼10, and yet no thermal runaway occurs over timespan ≃40 cooling times. Where time-averaged dissipation greater critical that creates hydrostatic equilibrium...

We present a detailed analysis of the magnetic field structure found in general relativistic 3D MHD simulations accreting tori Kerr metric with different black hole spins. Among properties analyzed are strength as function position and spin, shapes lines, degree to which they connect regions, their tangling. investigate prior speculations about fields discuss how frequently certain configurations seen simulations. also analyze distribution current density, view toward identifying possible...

(shortened) We calculate the vertical structure of a local patch an accretion disk in which heating by dissipation MRI-driven MHD turbulence is balanced radiative cooling. Heating, transport, and cooling are computed self-consistently with solving equations radiation shearing-box approximation. Using fully 3-d energy-conserving code, we compute this segment over span more than five times. After brief relaxation period, statistically steady-state develops. Measuring height above midplane...

Turbulence driven by magnetorotational instability (MRI) crucially affects the evolution of solid bodies in protoplanetary disks. On other hand, small dust particles stabilize MRI capturing ionized gas needed for coupling and magnetic fields. To provide an empirical basis modeling coevolution MRI, we perform three-dimensional, ohmic-resistive MHD simulations a vertically stratified shearing box with MRI-inactive "dead zone" various sizes net vertical flux strengths. We find that structure...

We study the properties of turbulence driven by magnetorotational instability in a stratified shearing box with outflow boundary conditions and an equation state determined self-consistent dissipation radiation losses. A series simulations increasing resolution are performed within fixed computational box. achieve numerical convergence respect to radial azimuthal resolution. As vertical is improved, ratio stress pressure increases slowly, but absolute levels both increase noticeably. These...

We present the results of local, vertically stratified, radiation magnetohydrodynamic (MHD) shearing box simulations magneto-rotational instability (MRI) turbulence appropriate for hydrogen ionizing regime dwarf nova and soft X-ray transient outbursts. incorporate frequency-integrated opacities equation state this regime, but neglect non-ideal MHD effects surface irradiation, do not impose net vertical magnetic flux. find two stable thermal equilibrium tracks in effective temperature versus...

We examine heating and cooling in protostellar disks using 3-D radiation-MHD calculations of a patch the Solar nebula at 1 AU, employing shearing-box flux-limited radiation diffusion approximations. The disk atmosphere is ionized by stellar X-rays, well-coupled to magnetic fields, sustains turbulent accretion flow driven magneto-rotational instability, while interior resistive magnetically dead. layers heat absorbing light from central star dissipating fields. They are optically-thin their...

view Abstract Citations (120) References (47) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Radio Jets and the Formation of Active Galaxies: Accretion Avalanches on Torus by Effect a Large-Scale Magnetic Field Matsumoto, R. ; Uchida, Y. Hirose, S. Shibata, K. Hayashi, M. Ferrari, A. Bodo, G. Norman, C. We present results 2.5-dimensional MHD simulations for magnetohydrodynamic model jet formation associated with active galaxies. also study enhanced accretion...

This paper continues the analysis of a set general relativistic three-dimensional MHD simulations accreting tori in Kerr metric with different black hole spins. We focus on bound matter inside initial pressure maximum, where time-averaged motion gas is inward and an accretion disk forms. use flows mass, angular momentum, energy order to understand dynamics this region. The sharp reduction rate increasing spin reported first series explained by strongly spin-dependent outward flux momentum...

Standard models of radiation supported accretion disks generally assume that diffusive flux is solely responsible for vertical heat transport. This requires must be generated at a critical rate per unit volume if the disk to in hydrostatic and thermal equilibrium. raises question how energy transported MHD turbulence. By analysis number radiation/MHD stratified shearing-box simulations, we show divergence indeed capped rate, but deep inside disk, substantial also carried by advection...

Accurate knowledge of the instrument transfer function (ITF) is vital for topography measurements using white‐light interferometry (WLI). To this end, we derive a complete set analytical expressions power spectral density (PSD) discretely-sampled binary pseudo‐random array (BPRA) as theoretical benchmark. We then determine ITF by comparing PSD with measured BPRA. For Zygo ZeGage™ Pro HR 50× objective, determined closely matches nominal modulation (MTF). Accordingly, integrate MTF into...

Accurate knowledge of the instrument transfer function (ITF) is vital for topography measurements using white‐light interferometry (WLI). To this end, we derive a complete set analytical expressions power spectral density (PSD) discretely-sampled binary pseudo‐random array (BPRA) as theoretical benchmark. We then determine ITF by comparing PSD with measured BPRA. For Zygo ZeGage™ Pro HR 50× objective, determined closely matches nominal modulation (MTF). Accordingly, integrate MTF into...

Accurate knowledge of the instrument transfer function (ITF) is vital for topography measurements using white‐light interferometry (WLI). To this end, we derive a complete set analytical expressions power spectral density (PSD) discretely-sampled binary pseudo‐random array (BPRA) as theoretical benchmark. We then determine ITF by comparing PSD with measured BPRA. For Zygo ZeGage™ Pro HR 50× objective, determined closely matches nominal modulation (MTF). Accordingly, integrate MTF into...

We present the results of a series radiation MHD simulations local patch an accretion disk, with fixed vertical gravity profile but different surface mass densities and broad range to gas pressure ratios. Each simulation achieves thermal equilibrium that lasts for many cooling times. After averaging over times are long compared time, we find vertically integrated stress is approximately proportional averaged total (gas plus radiation) pressure. map out—for first time on basis explicit...

Turbulence driven by magnetorotational instability (MRI) affects planetesimal formation inducing diffusion and collisional fragmentation of dust particles. We examine conditions preferred for in MRI-inactive "dead zones" using an analytic dead-zone model based on our recent resistive MHD simulations. argue that successful requires not only a sufficiently large dead zone (which can be produced tiny grains) but also small net vertical magnetic flux (NVF). Although often ignored, the latter...

The phenomenological Disc Instability Model has been successful in reproducing the observed light curves of dwarf nova outbursts by invoking an enhanced Shakura-Sunyaev $α$ parameter $\sim0.1-0.2$ outburst compared to a low value $\sim0.01$ quiescence. Recent thermodynamically consistent simulations magnetorotational (MRI) turbulence with appropriate opacities and equation state for accretion discs have found that thermal convection enhances outburst, but only near hydrogen ionization...

Young stars with masses 2–8 times solar, the Herbig Ae and Be stars, often show a near-infrared excess too large to explain hydrostatically supported circumstellar disk of gas dust. At same time, accretion flow carrying star is thought be driven by magnetorotational turbulence, which, according numerical MHD modeling, yields an extended low-density atmosphere magnetic fields. We demonstrate that base can optically thick starlight parts lying near 1 AU are tall enough double fraction stellar...

We investigated disk accretion onto a magnetized young star by performing MHD numerical simulations. considered the case in which stellar magnetosphere truncates carrying interstellar magnetic field, and is same direction as disk. In such case, interface between contains magnetically neutral ring equatorial plane. The results show that drives reconnection magnetospheric field allows mass transfer from to magnetosphere. Most of transferred accretes along reconnected while rest accelerated...

We present the results of one- and three-dimensional radiative transfer calculations polarized spectra emerging from snapshots radiation magnetohydrodynamical simulations local vertical structure black hole accretion disks. The cover a wide range physical regimes relevant for high/soft state X-ray binaries. constrain uncertainties in theoretical spectral color correction factors due to presence magnetic support disk surface layers strong density inhomogeneities. For radiation-dominated...

Using radiation magnetohydrodynamics simulations with realistic opacities and equation of state, zero net magnetic flux, we have explored thermodynamics in the inner part protoplanetary discs where turbulence is expected. The thermal equilibrium curve consists upper, lower, middle branches. upper (lower) branch corresponds to hot (cool) optically very (moderately) thick discs, respectively, while characterized by convective energy transport near midplane. Convection also major process low...

Stellar atmosphere models of ionized accretion disks have generally neglected the contribution magnetic fields to vertical hydrostatic support, although are widely believed play a critical role in transport angular momentum. Simulations magnetorotational turbulence vertically stratified shearing box geometry show that pressure support can be dominant upper layers disk. We present calculations disk spectra include this as well dissipation profile based on simulation. Magnetic generically...

We have employed a 3-d energy-conserving radiation MHD code to simulate the vertical structure and thermodynamics of shearing box whose parameters were chosen so that gas pressures would be comparable. The upper layers this disk segment are magnetically-dominated, creating conditions appropriate for both photon bubble Parker instabilities. find little evidence bubbles, even though simulation has enough spatial resolution see them their predicted growth rates high. On other hand, there is...

Vertically stratified shearing box simulations of magnetorotational turbulence commonly exhibit a so-called butterfly diagram quasi-periodic azimuthal field reversals. However, in the presence hydrodynamic convection, reversals no longer occur. Instead, strength fluctuates quasi-periodically while maintaining same polarity, which can either be symmetric or antisymmetric about disc midplane. Using data from Hirose et al. (2014), we demonstrate that lack convection is due to mixing magnetic...