☆ 4.7 Article

Dynamical effects of magnetic opacity in neutron star accretion columns

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Related references

Note: Only part of the references are listed.

Article Astronomy & Astrophysics

Dynamics of neutron star accretion columns in split-monopole magnetic fields

Lizhong Zhang et al.

Summary: We conducted 2D axisymmetric radiative relativistic MHD simulations on accretion columns in split-monopole magnetic fields of radiation pressure supported neutron stars. The oscillations of the accretion columns exhibit quasi-periodic behavior with peaks at 2-10 kHz in the luminosity power spectrum. The peak frequency decreases as the columns become wider or the mass accretion rates increase. pdV work plays a significant role in maintaining the radiation pressure against sideways radiative cooling inside the column, which is partly due to the compression associated with accretion along the converging magnetic field lines towards the stellar surface. Entropy waves formed by the slow-diffusion photon bubble instability are present in all simulations.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2023)

Add to Collection

Article Astronomy & Astrophysics

Ultraluminous X-ray sources

Andrew King et al.

Summary: The study of ultraluminous X-ray sources (ULXs) has undergone significant changes in the past decade. This review discusses the important observations of ULXs across different wavebands and scales in space and time. The recent progress and unanswered questions are considered, with a focus on the application of current theories to neutron-star ULXs.

NEW ASTRONOMY REVIEWS (2023)

Add to Collection

Article Astronomy & Astrophysics

Radiative relativistic magnetohydrodynamic simulations of neutron star column accretion in Cartesian geometry

Lizhong Zhang et al.

Summary: The study reveals that when high luminosity matter accretes onto a strongly magnetized neutron star, it forms a radiation pressure-dominated, magnetically confined accretion column. These columns are dynamically maintained through high-frequency oscillations of the accretion shock, which redistribute energy released at the shock through bulk vertical motions.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

Multigroup Radiation Magnetohydrodynamics Based on Discrete Ordinates including Compton Scattering

Yan-Fei Jiang

Summary: We present a formulation and numerical algorithm that extends the gray radiation magnetohydrodynamics (MHD) scheme to include frequency dependence. The algorithm can accurately handle a wide range of optical depth conditions, different coordinate systems, and adaptive mesh refinement.

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES (2022)

Add to Collection

Article Astronomy & Astrophysics

Mean opacities of a strongly magnetized high-temperature plasma

Valery F. Suleimanov et al.

Summary: The geometry and dynamical structure of emission regions in accreting pulsars are influenced by the interplay between gravity, radiation, and strong magnetic field. This study focuses on the quantitative consideration of magnetic plasma opacities in the modeling of emission regions in X-ray pulsars. The results show that the magnetic Planck mean opacity determines the radiative cooling of a strongly magnetized plasma and its value varies with temperature and magnetic field strength.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Add to Collection

Article Astronomy & Astrophysics

An Implicit Finite Volume Scheme to Solve the Time-dependent Radiation Transport Equation Based on Discrete Ordinates

Yan-Fei Jiang

Summary: This algorithm efficiently solves the RT equation coupled with the MHD equations using a conservative finite volume approach. By evolving specific intensities along discrete rays and using a Jacobi-like iteration scheme to remove time-step constraints, it simplifies the transport step by evolving intensities in the lab frame and transforming them to the comoving frame via Lorentz transformation during source term calculation. The time step is determined by the Courant-Friedrichs-Lewy condition in the MHD module, and various test problems demonstrate its accuracy and efficiency in both optically thick and thin regimes.

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES (2021)

Add to Collection

Article Astronomy & Astrophysics

Radiative MHD simulations of photon bubbles in radiation-supported magnetized atmospheres of neutron stars with isotropic Thomson scattering

Lizhong Zhang et al.

Summary: The study investigates the development of photon bubble instability in a static atmosphere, finding that the bubbles generally grow faster towards shorter wavelengths, leading to collapse of the atmosphere. Higher resolution simulations collapse faster due to the presence of shorter length-scale non-linear structures.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Add to Collection

Article Astronomy & Astrophysics

Polarization of accreting X-ray pulsars. I. A new model

Ilaria Caiazzo et al.

Summary: The development of X-ray polarimetry in high-energy astronomy will provide new insights into the emission mechanisms of accreting X-ray pulsars, requiring sound theoretical models as a basis.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Add to Collection

Article Astronomy & Astrophysics

The Athena plus plus Adaptive Mesh Refinement Framework: Design and Magnetohydrodynamic Solvers

James M. Stone et al.

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES (2020)

Add to Collection

Article Astronomy & Astrophysics

Super-critical column accretion on to strongly magnetized neutron stars in ULX pulsars

Tomohisa Kawashima et al.

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN (2020)

Add to Collection

Article Astronomy & Astrophysics

Cyclotron lines in highly magnetized neutron stars

R. Staubert et al.

ASTRONOMY & ASTROPHYSICS (2019)

Add to Collection

Article Astronomy & Astrophysics

Spectral and Timing Analysis of the Accretion-powered Pulsar 4U 1626-67 Observed with Suzaku and NuSTAR

Wataru B. Iwakiri et al.

ASTROPHYSICAL JOURNAL (2019)

Add to Collection

Article Astronomy & Astrophysics

Luminosity dependence of the cyclotron line and evidence for the accretion regime transition in V 0332+53

Victor Doroshenko et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2017)

Add to Collection

Article Astronomy & Astrophysics

Detection of cyclotron resonance scattering feature in high-mass X-ray binary pulsar SMC X-2

Gaurava K. Jaisawal et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2016)

Add to Collection

Article Astronomy & Astrophysics

AN ALGORITHM FOR RADIATION MAGNETOHYDRODYNAMICS BASED ON SOLVING THE TIME-DEPENDENT TRANSFER EQUATION

Yan-Fei Jiang et al.

ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES (2014)

Add to Collection

Article Astronomy & Astrophysics

Firm detection of a cyclotron resonance feature with Suzaku in the X-ray spectrum of GRO J1008-57 during a giant outburst in 2012

Takayuki Yamamoto et al.

PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN (2014)

Add to Collection

Article Astronomy & Astrophysics

A REFLECTION MODEL FOR THE CYCLOTRON LINES IN THE SPECTRA OF X-RAY PULSARS

Juri Poutanen et al.

ASTROPHYSICAL JOURNAL (2013)

Add to Collection

Article Astronomy & Astrophysics

Spectral formation in accreting X-ray pulsars: bimodal variation of the cyclotron energy with luminosity

P. A. Becker et al.

ASTRONOMY & ASTROPHYSICS (2012)

Add to Collection

Article Astronomy & Astrophysics

Completing the puzzle of the 2004-2005 outburst in V0332+53: the brightening phase included

S. S. Tsygankov et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2010)

Add to Collection

Article Astronomy & Astrophysics

Giant outburst of EXO 2030+375: pulse-phase resolved analysis of INTEGRAL data

D. Klochkov et al.

ASTRONOMY & ASTROPHYSICS (2008)

Add to Collection

Article Astronomy & Astrophysics

V0332+53 in the outburst of 2004-2005: luminosity dependence of the cyclotron line and pulse profile

S. S. Tsygankov et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2006)

Add to Collection

Article Astronomy & Astrophysics

Local radiative hydrodynamic and magnetohydrodynamic instabilities in optically thick media

O Blaes et al.

ASTROPHYSICAL JOURNAL (2003)

Add to Collection

© Peeref 2019-2024. All rights reserved.