Energy Flow and Radiation Efficiency in Radiative GRMHD Simulations of Neutron Star Ultraluminous X-Ray Sources

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F47813059%3A19630%2F25%3AA0000439" target="_blank" >RIV/47813059:19630/25:A0000439 - isvavai.cz</a>

Výsledek na webu

<a href="https://iopscience.iop.org/article/10.3847/1538-4357/ae11af" target="_blank" >https://iopscience.iop.org/article/10.3847/1538-4357/ae11af</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ae11af" target="_blank" >10.3847/1538-4357/ae11af</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Energy Flow and Radiation Efficiency in Radiative GRMHD Simulations of Neutron Star Ultraluminous X-Ray Sources

Popis výsledku v původním jazyce

We investigate numerically the energy flow and radiation efficiency of accreting neutron stars as potential ultraluminous X-ray sources (ULXs). We perform 10 simulations in radiative general relativistic magnetohydrodynamics, exploring six different magnetic dipole strengths ranging from 10 to 100 GigaGauss, along with three accretion rates, 100, 300, and 1000 Eddington luminosity units. Our results show that the energy efficiency in simulations with a strong magnetic dipole of 100 GigaGauss is approximately half that of simulations with a magnetic dipole an order of magnitude weaker. Consequently, radiation efficiency is lower in simulations with stronger magnetic dipoles. We also demonstrate that outflow power increases as the magnetic dipole weakens, resulting in stronger beaming in simulations with weaker magnetic dipoles. As a result of beaming, simulations with magnetic dipole strengths below 30 GigaGauss exhibit apparent luminosities consistent with those observed in ULXs. As for the accretion rates, we find that higher accretion rates lead to more powerful outflows, higher kinetic efficiency, and lower radiation efficiency compared to those of lower accretion rate simulations.

Název v anglickém jazyce

Energy Flow and Radiation Efficiency in Radiative GRMHD Simulations of Neutron Star Ultraluminous X-Ray Sources

Popis výsledku anglicky

We investigate numerically the energy flow and radiation efficiency of accreting neutron stars as potential ultraluminous X-ray sources (ULXs). We perform 10 simulations in radiative general relativistic magnetohydrodynamics, exploring six different magnetic dipole strengths ranging from 10 to 100 GigaGauss, along with three accretion rates, 100, 300, and 1000 Eddington luminosity units. Our results show that the energy efficiency in simulations with a strong magnetic dipole of 100 GigaGauss is approximately half that of simulations with a magnetic dipole an order of magnitude weaker. Consequently, radiation efficiency is lower in simulations with stronger magnetic dipoles. We also demonstrate that outflow power increases as the magnetic dipole weakens, resulting in stronger beaming in simulations with weaker magnetic dipoles. As a result of beaming, simulations with magnetic dipole strengths below 30 GigaGauss exhibit apparent luminosities consistent with those observed in ULXs. As for the accretion rates, we find that higher accretion rates lead to more powerful outflows, higher kinetic efficiency, and lower radiation efficiency compared to those of lower accretion rate simulations.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

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OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Svazek periodika

995

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

14

Strana od-do

„10-1“-„10-14“

Kód UT WoS článku

001629202700001

EID výsledku v databázi Scopus

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