Journal of High Energy Astrophysics最新文献

{"title":"Radiative back-reaction on charged particle motion in the dipole magnetosphere of neutron stars","authors":"Zdeněk Stuchlík,&nbsp;Jaroslav Vrba,&nbsp;Martin Kološ,&nbsp;Arman Tursunov","doi":"10.1016/j.jheap.2024.11.006","DOIUrl":"10.1016/j.jheap.2024.11.006","url":null,"abstract":"<div><div>The motion of charged particles under the Lorentz force in the magnetosphere of neutron stars, represented by a dipole field in the Schwarzschild spacetime, can be determined by an effective potential, whose local extrema govern circular orbits both in and off the equatorial plane, which coincides with the symmetry plane of the dipole field. In this work, we provide a detailed description of the properties of these “conservative” circular orbits and, using the approximation represented by the Landau-Lifshitz equation, examine the role of the radiative back-reaction force that influences the motion of charged particles following both the in and off equatorial circular orbits, as well as the chaotic orbits confined to belts centered around the circular orbits. To provide clear insight into these dynamics, we compare particle motion with and without the back-reaction force. We demonstrate that, in the case of an attractive Lorentz force, the back-reaction leads to the charged particles falling onto the neutron star's surface in all scenarios considered. For the repulsive Lorentz force, in combination with the back-reaction force, we observe a widening of stable equatorial circular orbits; the off-equatorial orbits shift toward the equatorial plane and subsequently widen if they are sufficiently close to the plane. Otherwise, the off-equatorial orbits evolve toward the neutron star surface. The critical latitude, which separates orbital widening from falling onto the surface, is determined numerically as a function of the electromagnetic interaction's intensity.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 500-530"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constraining anisotropic universe under f(R,T) theory of gravity","authors":"Lokesh Kumar Sharma ,&nbsp;Suresh Parekh ,&nbsp;Saibal Ray ,&nbsp;Anil Kumar Yadav","doi":"10.1016/j.jheap.2024.11.001","DOIUrl":"10.1016/j.jheap.2024.11.001","url":null,"abstract":"<div><div>We investigate the possibility of a Bianchi V universe in the modified gravitational field theory of <span><math><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><mi>T</mi><mo>)</mo></math></span>. We have considered a Lagrangian model in connection between the trace of the energy-momentum tensor <em>T</em> and the Ricci scalar <em>R</em>. In order to solve the field equations a power law for the scaling factor was also considered. To make a comparison of the model parameters with the observational data we put constraint on the model under the datasets of the Hubble parameter, Baryon Acoustic Oscillations, Pantheon, joint datasets of Hubble parameter + Pantheon and collective datasets of the Hubble parameter + Baryon Acoustic Oscillations + Pantheon. The outcomes for the Hubble parameter in the present epoch are reasonably acceptable, especially our estimation of this <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> is remarkably consistent with various recent Planck Collaboration studies that utilize the Λ-CDM model.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 457-467"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of anisotropic quark stars with interacting quark matter in f(R,T) gravity","authors":"Abdelghani Errehymy ,&nbsp;Indrani Karar ,&nbsp;Kairat Myrzakulov ,&nbsp;Ayan Banerjee ,&nbsp;Abdel-Haleem Abdel-Aty ,&nbsp;Kottakkaran Sooppy Nisar","doi":"10.1016/j.jheap.2024.10.016","DOIUrl":"10.1016/j.jheap.2024.10.016","url":null,"abstract":"&lt;div&gt;&lt;div&gt;We explore the structural properties of quark stars (QSs) in a modified gravity theory known as &lt;span&gt;&lt;math&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; gravity, which introduces a coupling between matter and spacetime geometry, through a basic linear functional form &lt;span&gt;&lt;math&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;. Our study focuses on QSs made of interacting quark matter (IQM) as an equation of state. We first derive the modified Tolman-Oppenheimer-Volkoff (TOV) equations for anisotropic matter in a spherically symmetric context and solve them numerically to obtain the structural properties of QSs. Stability is analyzed through static stability analysis, critical adiabatic indices, and sound speed profiles. Using astrophysical constraints from the “black widow” pulsar PSR J0952-0607 and the GW190814 event, we calibrate our model parameters. Our results indicate that with higher &lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;λ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;/math&gt;&lt;/span&gt;, both the maximum mass and radius of QSs increase, achieving a maximum mass of over &lt;span&gt;&lt;math&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, peaking at &lt;span&gt;&lt;math&gt;&lt;mn&gt;3.15&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; for a radius of &lt;span&gt;&lt;math&gt;&lt;mn&gt;14.90&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mtext&gt;km&lt;/mtext&gt;&lt;/math&gt;&lt;/span&gt; at &lt;span&gt;&lt;math&gt;&lt;mover&gt;&lt;mrow&gt;&lt;mi&gt;λ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;¯&lt;/mo&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0.9&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;. The maximum compactness also rises to &lt;span&gt;&lt;math&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0.313&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt; while adhering to the Buchdahl limit. Additionally, varying &lt;em&gt;β&lt;/em&gt; in the range &lt;span&gt;&lt;math&gt;&lt;mo&gt;[&lt;/mo&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;0.2&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;0.2&lt;/mn&gt;&lt;mo&gt;]&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; with fixed parameters shows that lower &lt;em&gt;β&lt;/em&gt; values enhance the maximum mass of QSs, reaching &lt;span&gt;&lt;math&gt;&lt;mn&gt;2.65&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; at &lt;span&gt;&lt;math&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;0.2&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;, with the compactness remaining around &lt;span&gt;&lt;math&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;≈&lt;/mo&gt;&lt;mn&gt;0.3&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;. Furthermore, changes in &lt;em&gt;μ&lt;/em&gt; from &lt;span&gt;&lt;math&gt;&lt;mo&gt;[&lt;/mo&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1.0&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;1.0&lt;/mn&gt;&lt;mo&gt;]&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; significantly affect maximum mass; at &lt;span&gt;&lt;math&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1.0&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;, the mass peaks at &lt;span&gt;&lt;math&gt;&lt;mn&gt;3.15&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and decrease to &lt;span&gt;&lt;math&gt;&lt;mn&gt;2.68&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; at &lt;span&gt;&lt;math&gt;&lt;mi&gt;μ&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;. The compactness increases with &lt;em&gt;μ&lt;/em&gt;, indicating that anisotropic pressure influences the &lt;span&gt;&lt;math&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; relations. In summary, our f","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 410-418"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weak cosmic censorship and weak gravity conjectures in CFT thermodynamics","authors":"Jafar Sadeghi ,&nbsp;Saeed Noori Gashti ,&nbsp;Mohammad Reza Alipour ,&nbsp;Mohammad Ali S. Afshar","doi":"10.1016/j.jheap.2024.11.004","DOIUrl":"10.1016/j.jheap.2024.11.004","url":null,"abstract":"<div><div>In this paper, we explore the intriguing interplay between fundamental theoretical physics concepts within the context of charged black holes. Specifically, we focus on the consistency of the weak gravity conjecture (WGC) and weak cosmic censorship conjecture (WCCC) in the thermodynamics of conformal field theory (CFT), and restricted phase space thermodynamics (RPST) for AdS Reissner-Nordström black holes with a perfect fluid dark matter (RN-PFDM). The WGC ensures that gravity remains the weakest force in the system. Meanwhile, the WCCC addresses the cosmic censorship problem by preventing the violation of fundamental physical laws near the black hole singularity. First, we analyze the RN black hole's free energy in both spaces, revealing a distinctive swallowtail pattern indicative of a first-order phase transition when certain free parameter conditions are met. We explore the WGC across different phase spaces, emphasizing the need for certain conditions in extended phase space thermodynamics (EPST), RPST, and CFT. We demonstrate that PFDM parameter <em>γ</em> and the radius of AdS <em>l</em> have a vital role in proving the satisfaction of the WGC. Also, these values have a linear relation with the range compatibility of WGC. The range of compatibility for WGC in RPST and EPST is the same while for CFT, this range is larger than EPST, and RPST. It means somehow the WGC and CFT are more consistent. The WCCC was examined at the critical juncture, confirming its validity in critical points. We conclude that the WGC is supported at the critical point of black holes, and the WCCC is also maintained, demonstrating the robustness of these conjectures within the critical ranges of black hole parameters.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 482-493"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exact solution to the Wheeler-DeWitt equation: Early and current Universe","authors":"David Senjaya","doi":"10.1016/j.jheap.2024.11.007","DOIUrl":"10.1016/j.jheap.2024.11.007","url":null,"abstract":"<div><div>In this paper, we present exact solutions to the Wheeler-DeWitt equation in two different scenarios: the early Universe, where the ordering parameter of kinetic energy is important, and the current Universe, where the ordering parameter effect is negligible. To make the exact solutions as general as possible, we incorporate as many different types of energy density as possible into the Hamiltonian, including baryonic and non-baryonic matter (dark matter), radiation, vacuum, and quintessence (dark energy). In the early Universe scenario, we obtain exact solutions in terms of the Biconfluent Heun functions, whereas in the current Universe, the exact solutions are given in terms of the Triconfluent Heun functions. Furthermore, by applying the polynomial conditions to each case, we obtain a constraint equation that supports the notion that the Wheeler-DeWitt equation can be viewed as an eigenvalue problem for the cosmological constant.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 494-499"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"General relativistic viscous accretion flow around Konoplya-Zhidenko black hole","authors":"Subhankar Patra,&nbsp;Bibhas Ranjan Majhi,&nbsp;Santabrata Das","doi":"10.1016/j.jheap.2024.10.012","DOIUrl":"10.1016/j.jheap.2024.10.012","url":null,"abstract":"<div><div>We investigate the properties of accretion flows around the Konoplya-Zhidenko (KZ) black hole, which is proposed by deforming the Kerr metric with a single deformation parameter to test the no-hair theorem using gravitational wave observations. The dynamical equations describing the general relativistic viscous accreting flow are solved self-consistently to find the transonic accretion solutions in terms of global constants, such as energy (<em>E</em>), angular momentum (<span><math><mi>L</mi></math></span>), viscosity parameter (<em>α</em>), spin (<span><math><msub><mrow><mi>a</mi></mrow><mrow><mi>k</mi></mrow></msub></math></span>), and deformation parameter (<span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>). We obtain five distinct types of accretion solutions (O, A, <span><math><msup><mrow><mtext>A</mtext></mrow><mrow><mo>′</mo></mrow></msup></math></span>, W, and I-types), and observe that those solutions are not unique but rather continue to exist for wide range of parameter spaces in the <span><math><mi>L</mi><mo>−</mo><mi>E</mi></math></span> plane. Furthermore, we find that the viscous accretion flows can harbor shock waves when the relativistic shock conditions are satisfied. Consequently, the shock-induced global accretion solutions are obtained, and the effect of <span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> on shock properties, such as shock radius (<span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>sh</mi></mrow></msub></math></span>) and change in electron temperature (<span><math><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi></mrow></msub></math></span>) across the shock front are investigated. Moreover, we calculate the spectral energy distributions (SEDs) of accretion flow using the relativistic thermal bremsstrahlung emission coefficient and study the modification of SEDs due to the increase of <span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> for both shock-induced and shock-free solutions. In addition, it has been noticed that the observable quantities, like quasi-periodic oscillation frequency (<span><math><msub><mrow><mi>ν</mi></mrow><mrow><mi>QPO</mi></mrow></msub></math></span>) and bolometric disc luminosity (<em>L</em>), are strongly dependent on <span><math><msub><mrow><mi>η</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>. Finally, we phenomenologically show that the KZ black hole is consistent with the high-frequency QPOs, commonly observed in black hole binaries and black hole candidates.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 371-380"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum-gravitational effects on Joule-Thomson expansion and black hole shadows in F(R) gravity with barrow entropy corrections","authors":"Muhammad Yasir ,&nbsp;Xia Tiecheng ,&nbsp;Shahid Chaudhary ,&nbsp;Abdulrahman Bin Jumah","doi":"10.1016/j.jheap.2024.10.006","DOIUrl":"10.1016/j.jheap.2024.10.006","url":null,"abstract":"<div><div>We present a novel investigation into the thermodynamic properties and shadow images of a topological phantom AdS black hole within the framework of <span><math><mi>F</mi><mo>(</mo><mi>R</mi><mo>)</mo></math></span> gravity, utilizing the Barrow entropy formulation. We introduce a detailed study of the Joule-Thomson expansion, calculating the Joule-Thomson coefficient and mapping isenthalpic and inversion curves to characterize heating/cooling phases. Our findings reveal that the Barrow parameter plays a crucial role in altering the shape and position of these thermodynamic curves, thereby significantly impacting the black hole's thermal behavior. Moreover, we demonstrate that variations in <span><math><mi>F</mi><mo>(</mo><mi>R</mi><mo>)</mo></math></span> gravity parameters such as the scalar curvature <span><math><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, the type of field interaction <em>η</em>, and <span><math><msub><mrow><mi>f</mi></mrow><mrow><msub><mrow><mi>R</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></msub></math></span>—lead to substantial modifications in the shadow of the black hole. These changes in shadow size and shape underscore the direct influence of the underlying gravitational theory on the interaction between black holes and light, offering new perspectives on how black holes are perceived by distant observers. Additionally, we calculate the total observed intensities from the emission function of the accretion disk, with graphical analysis showing that the <span><math><mi>F</mi><mo>(</mo><mi>R</mi><mo>)</mo></math></span> gravity parameters markedly affect the intensity distribution around the black hole. This has significant implications for the accretion disk's emission properties and the resulting shadow image, highlighting the critical impact of modified gravity theories on observable black hole phenomena. This work offers fresh insights and underscores the importance of considering modified gravity frameworks when studying black hole thermodynamics and optical properties.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 356-370"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Joule-Thomson expansion, motion of particles and QPOs around Bardeen-AdS black hole immersed in a fluid of strings","authors":"G. Mustafa ,&nbsp;Faisal Javed ,&nbsp;S.K. Maurya ,&nbsp;Shalan Alkarni ,&nbsp;Orhan Donmez ,&nbsp;Arzu Cilli ,&nbsp;Ertan Güdekli","doi":"10.1016/j.jheap.2024.10.017","DOIUrl":"10.1016/j.jheap.2024.10.017","url":null,"abstract":"<div><div>In this work, we investigate the dynamics of particles around a Bardeen AdS black hole immersed in a fluid of strings, focusing on how the black hole parameters affect particle motion. We observe the black hole's Joule-Thomson expansion and the impact of physical parameters on the cooling and heating zones. Using Joule-Thomson coefficients, we also discuss the stable and unstable configuration of the considered black hole for both cases. The stability of circular equatorial orbits is analyzed using the effective potential approach. We derive analytical expressions for the energy and angular momentum of these circular orbits as functions of the black hole parameters. We also explore the impact of these parameters on the innermost stable circular orbits and discuss the effective forces acting on the particles. In addition, we examine the epicyclic oscillations of particles near a stable equatorial orbits and calculate the corresponding oscillation frequencies as function of black hole parameters. The periastron frequency is also analyzed. Furthermore, we study particle collisions and the resulting center of mass-energy in the vicinity of the black hole. We show that the parameters of the model significantly influence particle motion. Lastly, we compare the particle dynamics around the Bardeen AdS black hole immersed in a fluid of strings with those around the Bardeen black hole and the Bardeen Reissner-Nordström black hole.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 437-456"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spin and spectral properties of Cygnus X-1 observed with Insight-HXMT","authors":"Yihao Zhu,&nbsp;Hanji Wu,&nbsp;Wei Wang","doi":"10.1016/j.jheap.2024.10.013","DOIUrl":"10.1016/j.jheap.2024.10.013","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Cygnus X-1 is a Galactic black hole X-ray binary with persistent X-ray emissions. We examine the spectral data from 2 – 22 keV gathered by Insight-HXMT observations conducted from 2020 to 2022. We use the continuum-fitting method to constrain three parameters of Cygnus X-1: the black hole spin &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⁎&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, the hydrogen column density &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, and the photon index of the powerlaw component Γ. The fittings constrain &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;1.1&lt;/mn&gt;&lt;mo&gt;±&lt;/mo&gt;&lt;mn&gt;0.1&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;22&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; atom cm&lt;sup&gt;−2&lt;/sup&gt;, and Γ evolving from ∼2.4 in 2020 to ∼1.9 in 2022. We find the dimensionless spin parameter &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⁎&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;mn&gt;0.977&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt; &lt;span&gt;&lt;math&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; assuming the distance of the source &lt;span&gt;&lt;math&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;2.22&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt; kpc, the mass of the black hole &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;BH&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;21.4&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, and the inclination of the system &lt;span&gt;&lt;math&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;27.47&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;. Furthermore, considering the uncertainty of &lt;em&gt;D&lt;/em&gt; from 1.22 kpc to 3.22 kpc, &lt;span&gt;&lt;math&gt;&lt;mn&gt;16&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;BH&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;mn&gt;25&lt;/mn&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⊙&lt;/mo&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;22&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;mo&gt;&lt;&lt;/mo&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mn&gt;31&lt;/mn&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;∘&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, the Monte Carlo analysis is performed and still confirms a large spin of the limitation &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⁎&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;mn&gt;0.999&lt;/mn&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mi&gt;σ&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt; without the &lt;em&gt;D&lt;/em&gt;, &lt;em&gt;i&lt;/em&gt;, and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;BH&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; bias for Cygnus X-1. We also try to use the limits of &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⁎&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; to reversely constrain the range of &lt;em&gt;D&lt;/em&gt;, &lt;em&gt;i&lt;/em&gt;, and &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;BH&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;, and find that for the extreme situation (&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mo&gt;⁎&lt;/mo&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;mn&gt;0.99&lt;/mn&gt;&lt;/math&gt;&lt;/span&gt;), the derived distributions prefer a low &lt;em&gt;i&lt;/em&gt;, large &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;BH&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 381-392"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neutrino emission due to pair – annihilation in the neutron star magnetic field","authors":"Shiladittya Debnath ,&nbsp;Brajagopal Majumder","doi":"10.1016/j.jheap.2024.11.005","DOIUrl":"10.1016/j.jheap.2024.11.005","url":null,"abstract":"<div><div>In this paper, we have calculated the energy loss in terms of luminosity for neutrinos produced by the annihilation of electron–positron pair in the light of Photo – Neutrino weak interaction with an intense magnetic field. After analytical calculation, we may conclude that the neutrino luminosity increases with the magnetic field in the temperature range of 10⁸ to 10¹² Kelvins giving rise to an energy loss channel. This may provide an alternate cooling mechanism for highly magnetized neutron stars. We have also conducted a comparative study of neutrino emission from magnetized neutron stars based on both Photo–Neutrino interaction and Conventional (current – current) weak interaction. We found a remarkable similarity between the two models on temperature versus energy loss behaviour of neutron stars. However, these are found to differ from one another on the overall time scale of evolution.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 468-481"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}