Distinguishing magnetically and electrically charged Reissner–Nordström black holes by magnetized particle motion
Аннотация
Abstract In the present paper, we investigate the dynamics of magnetized particles around magnetically and electrically Reissner–Nordström (RN) black hole. The main idea of the work is to distinguish the effects of electric and magnetic charges of the RN black hole and spin of the rotating Kerr black hole through the dynamics of the magnetized particles. In this study, we have treated a magnetized neutron star as a magnetized test particle, in particular, the magnetar SGR (PSR) J1745-2900 orbiting around the supermassive black hole Sagittarius A* (SMBH SgrA*) with the magnetic interaction parameter $$b=0.716$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>b</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0.716</mml:mn> </mml:mrow> </mml:math> and the parameter $$\beta =10.2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>β</mml:mi> <mml:mo>=</mml:mo> <mml:mn>10.2</mml:mn> </mml:mrow> </mml:math> . The comparison of the effects of the magnetic and electric charges, and magnetic interaction parameters on the dynamics of the magnetar modeled as a magnetized particle near the SMBH Sgr A* has shown that the magnetic charge of the RN black hole can mimic the spin parameter of a rotating Kerr black hole up to $$a/M \simeq 0.82$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>a</mml:mi> <mml:mo>/</mml:mo> <mml:mi>M</mml:mi> <mml:mo>≃</mml:mo> <mml:mn>0.82</mml:mn> </mml:mrow> </mml:math> . The external magnetic field can mimic the magnetic charge of the RN black hole up to $$Q_m/M=0.4465$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>Q</mml:mi> <mml:mi>m</mml:mi> </mml:msub> <mml:mo>/</mml:mo> <mml:mi>M</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0.4465</mml:mn> </mml:mrow> </mml:math> . We have shown that the electric charge of the RN black hole can mimic the black hole magnetic charge up to $$Q_m/M=0.5482$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>Q</mml:mi> <mml:mi>m</mml:mi> </mml:msub> <mml:mo>/</mml:mo> <mml:mi>M</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0.5482</mml:mn> </mml:mrow> </mml:math> and the magnetic field interaction with the magnetized particle acts against the increase of the mimicking value of the black hole spin parameter. The studies may be helpful to explain the observability of radio pulsars around the SMBH SgrA* system and taking it as a real astrophysical laboratory to get more precise constraints on the central black hole and dominated parameters of the alternate gravity. Finally, we have investigated the effects of magnetic and electric charge of the RN black hole in the center-of-mass energy of head-on collisions of magnetized particles with neutral, electrically charged, and magnetized particles. Both electric and magnetic charges of the RN black hole would lead to an increase in the center of the mass–energy of the collisions.