Quasar continuum spectrum disfavors black holes with a magnetic monopole charge

Banerjee, Indrani; Chawan, Vijay Shersingh; Mandal, Bhaswati; Sahoo, Siddharth Kumar; SenGupta, Soumitra

doi:10.1103/physrevd.105.064073

“…It may be important to note that even if we consider χ 2 min corresponding to g 0.25 the bounds on the monopole charge parameter turns out to be very stringent when RPM is considered and like all the other QPO models very high values of g seem to be disfavored from observations associated with QPOs. Interestingly, our present result is in agreement with our previous findings where we compare the theoretical spectrum from the accretion disk with the optical observations of quasars and note that the Kerr scenario is more favored compared to the Bardeen black holes [110].…”

Section: Jcap05(2022)020supporting

confidence: 93%

Deciphering signatures of Bardeen black holes from the observed quasi-periodic oscillations

Banerjee

¹

2022

J. Cosmol. Astropart. Phys.

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Quasi-periodic oscillations (QPOs) observed in the power spectrum of black holes are unique observational probes to the background spacetime since they can be directly related to the timescales associated with the motion of matter orbiting in the vicinity of the black hole horizon. In this regard, the high frequency QPOs (HFQPOs) are particularly interesting as they occur in commensurable pairs, the most common ratio being the 3:2 twin peak QPOs. The theoretical models which aim to explain these QPOs express the observed frequencies in terms of the epicyclic motion of test particles in a given background spacetime. In this work, we study the signatures of Bardeen spacetime from the observed QPOs in the black hole power spectrum. Bardeen black holes are rotating, regular black holes with a magnetic monopole charge. Such regular backgrounds are theoretically interesting as they can potentially evade the curvature singularity, otherwise unavoidable in general relativistic black holes. We perform a χ2 analysis by comparing the available observations of the quasi-periodic oscillations from black hole sources with the relevant theoretical models and note that the Kerr black holes in general relativity are observationally more favored compared to black holes with a monopole charge. Our analysis reveals that black holes with very high monopole charges are disfavored from QPO related observations.

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“…The observational signatures of regular black holes have been studied quite extensively [49][50][51][52][53][54][55][56][57][58][59][60][61]. In this work we investigate the nature of the black hole shadow cast by the regular black holes discussed above.…”

Section: Jcap09(2022)066mentioning

confidence: 99%

Signatures of regular black holes from the shadow of Sgr A* and M87*

Banerjee

¹

,

Sau

²

,

SenGupta

³

2022

J. Cosmol. Astropart. Phys.

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With the recent release of the black hole image of Sgr A* alongside the earlier image of M87*, one can now really hope to acquire a better understanding of the gravitational physics at the horizon scale. In this paper, we investigate the prospect of the regular black hole scenario with a Minkowski core in explaining the observed shadow of M87* and Sgr A*. Regular black holes generally appear in Einstein gravity coupled to non-linear electrodynamics and are interesting as they can evade the r = 0 curvature singularity arising in general relativity. Using the previously determined mass and distance we compute the observables associated with the black hole shadow. These when compared with the observed angular diameter reveals that the shadow of M87* and Sgr A* favor the regular black hole scenario with a small but non-zero charge. The implications are discussed.

show abstract

“…The observational signatures of regular black holes have been studied quite extensively [49][50][51][52][53][54][55][56][57][58][59]. In this work we investigate the nature of the black hole shadow cast by the regular black holes discussed above.…”

Section: Introductionmentioning

confidence: 99%

Signatures of regular black holes from the shadow of Sgr A* and M87*

Banerjee¹,

Sau²,

SenGupta³

2022

Preprint

Self Cite

View full text Add to dashboard Cite

With the recent release of the black hole image of Sgr A* alongside the earlier image of M87*, one can now really hope to acquire a better understanding of the gravitational physics at the horizon scale. In this paper, we investigate the prospect of the regular black hole scenario with a Minkowski core in explaining the observed shadow of M87* and Sgr A*. Regular black holes generally appear in Einstein gravity coupled to non-linear electrodynamics and are interesting as they can evade the r = 0 curvature singularity arising in general relativity. Using the previously determined mass and distance we compute the observables associated with the black hole shadow. These when compared with the observed angular diameter reveals that the shadow of M87* and Sgr A* favor the regular black hole scenario with a small but non-zero charge. The implications are discussed.

show abstract

Quasar continuum spectrum disfavors black holes with a magnetic monopole charge

Cited by 4 publications

References 79 publications

Deciphering signatures of Bardeen black holes from the observed quasi-periodic oscillations

Deciphering signatures of Bardeen black holes from the observed quasi-periodic oscillations

Signatures of regular black holes from the shadow of Sgr A* and M87*

Signatures of regular black holes from the shadow of Sgr A* and M87*

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