Cusp structure in shadows casted by rotating wormholes

Gyulchev, Galin; Nedkova, Petya; Tinchev, Vassil K.; Yazadjiev, Stoytcho S.

doi:10.1063/1.5091165

Cited by 10 publications

(6 citation statements)

References 20 publications

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“…In literature, the theory of black hole shadows is well-developed and is under investigation for decades. After the seminal work of Synge [9] and [10] on the apparent shape of a spherically symmetric black hole and the appearance Schwarzschild black hole, some notable results of BH shadows are already discussed in the literature, to list a few: The shadow of a Kerr black hole was studied by Bardeen [11], shadow of Kerr-Newman black holes [12], naked singularities with deformation parameters [13], Kerr-Nut spacetimes [14], while shadows of black holes in Chern-Simons modified gravity, Randall-Sundrum braneworlds, and Kaluza-Klein rotating black holes have been studied in [15][16][17], shadow of Kerr-Perfect fluid dark matter BH [18][19][20][21] and rotating global monopoles with dark matter [22] and many other interesting studies concerning the Kerr-like wormholes as well as traversable wormholes and many others interesting studies [23][24][25][26][27][28]. Some authors have also tried to test theories of gravity by using the observations obtained from shadow of Sgr A* [30][31][32][33]; Einstein-dilaton-Gauss-Bonnet BH [35]; Konoplya-Zhidenko BH [36]; Einstein-Maxwell-Chern-Simon BH [37]; Kerr-Newman-Kasuya BH [38]; Kerr de Sitter BH [39]; Kerr-MOG BH [40]; rotating regular BH [41]; Kerr-Sen BH [42]; non-commutative BHs [43]; naked singularities [44,45], etc.…”

Section: Radius Distortion and Energy Emission 16mentioning

confidence: 99%

Black hole surrounded by a dark matter halo in the M87 galactic center and its identification with shadow images

et al. 2019

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In this paper we present a new black hole solution surrounded by dark matter halo in the galactic center using the mass model of M87 and that coming from the Universal Rotation Curve (URC) dark matter profile representing family of spiral galaxies. In both cases the DM halo density is cored with a size r 0 and a central density ρ 0 : ρ(r) = ρ 0 /(1 + r/r 0 )(1 + (r/r 0 ) 2 ). Since r 0 ρ 0 = 120 M /pc 2 [5], then by varying the central density one can reproduce the DM profile in any spiral. Using the Newman-Jains method we extend our solution to obtain a rotating black hole surrounded by dark matter halo. We find that, the apparent shape of the shadow beside the black hole spin a, it also depends on the central density of the surrounded dark matter ρ 0 . As a specific example we consider the galaxy M87, with a central density ρ 0 = 6.9 × 10 6 M /kpc 3 and a core radius r 0 = 91.2 kpc. In the case of M87, our analyses show that the effect of dark matter on the size of the black hole shadow is almost negligible compared to the shadow size of the Kerr vacuum solution hence the angular diameter 42 µas remains almost unaltered when the dark matter is considered. For a small totally dark matter dominated spiral such as UGC 7232, we find similar effect of dark matter on the shadow images compared to the M87. However, in specific conditions having a core radius comparable to the black hole mass and dark matter with very high density, we show that the shadow images decreases compared to the Kerr vacuum black hole. The effect of dark matter on the apparent shadow shape can shed some light in future observations as an indirect way to detect dark matter using the shadow images. Contents

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Section: Radius Distortion and Energy Emission 16mentioning

confidence: 99%

Black hole surrounded by a dark matter halo in the M87 galactic center and its identification with shadow images

et al. 2019

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“…To calculate the radial acceleration on a test baryonic particle within the superfluid core this is given by the sum of three contributions [53] a(r ) = a B (r ) + a DM (r ) + a phonon (r ), (25) where the first term is just the baryonic Newtonian acceleration a B = M B (r )/r 2 . The second term is the gravitational acceleration from the superfluid core, a DM = M DM (r )/r 2 .…”

Section: Effect Of Baryonic Matter and Superfluid Dark Mattermentioning

confidence: 99%

Shadows of Sgr A$$^{*}$$ black hole surrounded by superfluid dark matter halo

2020

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In this paper we construct a black hole solution surrounded by superfluid dark matter and baryonic matter, and study their effects on the shadow images of the Sgr A$$^{*}$$∗ black hole. To achieve this goal, we have considered two density profiles for the baryonic matter described by the spherical exponential profile and the power law profile including a special case describing a totally dominated dark matter galaxy. Using the present values for the parameters of the superfluid dark matter and baryonic density profiles for the Sgr A$$^{*}$$∗ black hole, we find that the effects of the superfluid dark matter and baryonic matter on the size of shadows are almost negligible compared to the Kerr vacuum black hole. In addition, we find that by increasing the baryonic mass the shadow size increases considerably. This result can be linked to the matter distribution in the galaxy, namely the baryonic matter is mostly located in the galactic center and, therefore, increasing the baryonic matter can affect the size of black hole shadow compared to the totally dominated dark matter galaxy where we observe an increase of the angular diameter of the Sgr A$$^{*}$$∗ black hole of the magnitude $$10^{-5}\,\upmu $$10-5μarcsec.

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“…Historically, Synge was the first to propose the apparent shape of a spherically symmetric black hole [7]. After that Luminet [8] discussed the appearance of a Schwarzschild black hole, the shadow of a Kerr black hole was studied by Bardeen [9], shadow of Kerr-Newman black holes [10], naked singularities with deformation parameters [11], Kerr-Nut spacetimes [12], while shadows of black holes in Chern-Simons modified gravity, Randall-Sundrum braneworlds, and Kaluza-Klein rotating black holes have been studied in [13][14][15], and many other interesting studies concerning the effect of dark matter and cosmological constant on the shadow images [16][17][18][19][20][21][22]24], Kerr-like wormholes as well as traversable wormholes and many others interesting studies [25][26][27][28][29][30][31][32][33]. Some authors have also tried to test theories of gravity by using the observations obtained from shadow of Sgr A* [34][35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Shadow Images of a Rotating Dyonic Black Hole with a Global Monopole Surrounded by Perfect Fluid

2020

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In this paper we revisit and extend the prior work of Filho and Bezerra [1] to rotating dyonic global monopoles in presence of a perfect fluid. We then show that the surface topology at the event horizon, related to the metric computed, is a 2-sphere using the Gauss-Bonnet theorem. By choosing ω = −1/3, 0, 1/3 we investigate the effect of dark matter, dust, radiation on the silhouette of black hole. The presence of the global monopole parameter γ and the perfect fluid parameters υ, also deforms the shape of black hole's shadow, which has been depicted through graphical illustrations. In the end we analyse energy emission rate of rotating dyonic global monopole surrounded by perfect fluid with respect to parameters.

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Cusp structure in shadows casted by rotating wormholes

Cited by 10 publications

References 20 publications

Black hole surrounded by a dark matter halo in the M87 galactic center and its identification with shadow images

Black hole surrounded by a dark matter halo in the M87 galactic center and its identification with shadow images

Shadows of Sgr A$$^{*}$$ black hole surrounded by superfluid dark matter halo

Shadow Images of a Rotating Dyonic Black Hole with a Global Monopole Surrounded by Perfect Fluid

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