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Title: 3D MHD Simulations of accreting neutron stars: evidence of QPO emission from the surface

Abstract

3D Magnetohydrodynamic simulations show that when matter accretes onto neutron stars, in particular if the misalignment angle is small, it does not constantly fall at a fixed spot. Instead, the location at which matter reaches the star moves. These moving hot spots can be produced both during stable accretion, where matter falls near the magnetic poles of the star, and unstable accretion, characterized by the presence of several tongues of matter which fall on the star near the equator, due to Rayleigh-Taylor instabilities. Precise modeling with Monte Carlo simulations shows that those movements could be observed as high frequency Quasi Periodic Oscillations. We performed a number of new simulation runs with a much wider set of parameters, focusing on neutron stars with a small misalignment angle. In most cases we observe oscillations whose frequency is correlated with the mass accretion rate M. Moreover, in some cases double QPOs appear, each of them showing the same correlation with M.

Authors:
;  [1]; ;  [2];  [3]
  1. Universita degli Studi di Cagliari (Italy)
  2. Cornell University (United States)
  3. Universita degli Studi di Palermo (Italy)
Publication Date:
OSTI Identifier:
21413473
Resource Type:
Journal Article
Journal Name:
AIP Conference Proceedings
Additional Journal Information:
Journal Volume: 1248; Journal Issue: 1; Conference: International conference on X-ray astronomy 2009: Present status, multi-wavelength approach and future perspectives, Bologna (Italy), 7-11 Sep 2009; Other Information: DOI: 10.1063/1.3475164; (c) 2010 American Institute of Physics; Journal ID: ISSN 0094-243X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ACCRETION DISKS; COMPUTERIZED SIMULATION; CORRELATIONS; EMISSION; EQUATOR; HOT SPOTS; MAGNETOHYDRODYNAMICS; MASS; MONTE CARLO METHOD; NEUTRON STARS; OSCILLATIONS; PERIODICITY; RAYLEIGH-TAYLOR INSTABILITY; SURFACES; CALCULATION METHODS; FLUID MECHANICS; HYDRODYNAMICS; INSTABILITY; MECHANICS; SIMULATION; STARS; VARIATIONS

Citation Formats

Bachetti, Matteo, Burderi, Luciano, Romanova, Marina M, Kulkarni, Akshay, and Salvo, Tiziana di. 3D MHD Simulations of accreting neutron stars: evidence of QPO emission from the surface. United States: N. p., 2010. Web. doi:10.1063/1.3475164.
Bachetti, Matteo, Burderi, Luciano, Romanova, Marina M, Kulkarni, Akshay, & Salvo, Tiziana di. 3D MHD Simulations of accreting neutron stars: evidence of QPO emission from the surface. United States. https://doi.org/10.1063/1.3475164
Bachetti, Matteo, Burderi, Luciano, Romanova, Marina M, Kulkarni, Akshay, and Salvo, Tiziana di. 2010. "3D MHD Simulations of accreting neutron stars: evidence of QPO emission from the surface". United States. https://doi.org/10.1063/1.3475164.
@article{osti_21413473,
title = {3D MHD Simulations of accreting neutron stars: evidence of QPO emission from the surface},
author = {Bachetti, Matteo and Burderi, Luciano and Romanova, Marina M and Kulkarni, Akshay and Salvo, Tiziana di},
abstractNote = {3D Magnetohydrodynamic simulations show that when matter accretes onto neutron stars, in particular if the misalignment angle is small, it does not constantly fall at a fixed spot. Instead, the location at which matter reaches the star moves. These moving hot spots can be produced both during stable accretion, where matter falls near the magnetic poles of the star, and unstable accretion, characterized by the presence of several tongues of matter which fall on the star near the equator, due to Rayleigh-Taylor instabilities. Precise modeling with Monte Carlo simulations shows that those movements could be observed as high frequency Quasi Periodic Oscillations. We performed a number of new simulation runs with a much wider set of parameters, focusing on neutron stars with a small misalignment angle. In most cases we observe oscillations whose frequency is correlated with the mass accretion rate M. Moreover, in some cases double QPOs appear, each of them showing the same correlation with M.},
doi = {10.1063/1.3475164},
url = {https://www.osti.gov/biblio/21413473}, journal = {AIP Conference Proceedings},
issn = {0094-243X},
number = 1,
volume = 1248,
place = {United States},
year = {Thu Jul 15 00:00:00 EDT 2010},
month = {Thu Jul 15 00:00:00 EDT 2010}
}