Pub Date : 2024-11-01DOI: 10.1016/j.jheap.2024.10.017
G. Mustafa , Faisal Javed , S.K. Maurya , Shalan Alkarni , Orhan Donmez , Arzu Cilli , Ertan Güdekli
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.
{"title":"Joule-Thomson expansion, motion of particles and QPOs around Bardeen-AdS black hole immersed in a fluid of strings","authors":"G. Mustafa , Faisal Javed , S.K. Maurya , Shalan Alkarni , Orhan Donmez , Arzu Cilli , 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}
Pub Date : 2024-11-01DOI: 10.1016/j.jheap.2024.10.013
Yihao Zhu, Hanji Wu, Wei Wang
<div><div>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 <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>, the hydrogen column density <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span>, and the photon index of the powerlaw component Γ. The fittings constrain <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>H</mi></mrow></msub><mo>=</mo><mo>(</mo><mn>1.1</mn><mo>±</mo><mn>0.1</mn><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>22</mn></mrow></msup></math></span> atom cm<sup>−2</sup>, and Γ evolving from ∼2.4 in 2020 to ∼1.9 in 2022. We find the dimensionless spin parameter <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>></mo><mn>0.977</mn></math></span> <span><math><mo>(</mo><mn>3</mn><mi>σ</mi><mo>)</mo></math></span> assuming the distance of the source <span><math><mi>D</mi><mo>=</mo><mn>2.22</mn></math></span> kpc, the mass of the black hole <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub><mo>=</mo><mn>21.4</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, and the inclination of the system <span><math><mi>i</mi><mo>=</mo><msup><mrow><mn>27.47</mn></mrow><mrow><mo>∘</mo></mrow></msup></math></span>. Furthermore, considering the uncertainty of <em>D</em> from 1.22 kpc to 3.22 kpc, <span><math><mn>16</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub><mo><</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub><mo><</mo><mn>25</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><msup><mrow><mn>22</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo><</mo><mi>i</mi><mo><</mo><msup><mrow><mn>31</mn></mrow><mrow><mo>∘</mo></mrow></msup></math></span>, the Monte Carlo analysis is performed and still confirms a large spin of the limitation <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>></mo><mn>0.999</mn><mo>(</mo><mn>1</mn><mi>σ</mi><mo>)</mo></math></span> without the <em>D</em>, <em>i</em>, and <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub></math></span> bias for Cygnus X-1. We also try to use the limits of <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span> to reversely constrain the range of <em>D</em>, <em>i</em>, and <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub></math></span>, and find that for the extreme situation (<span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>></mo><mn>0.99</mn></math></span>), the derived distributions prefer a low <em>i</em>, large <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub
{"title":"Spin and spectral properties of Cygnus X-1 observed with Insight-HXMT","authors":"Yihao Zhu, Hanji Wu, Wei Wang","doi":"10.1016/j.jheap.2024.10.013","DOIUrl":"10.1016/j.jheap.2024.10.013","url":null,"abstract":"<div><div>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 <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span>, the hydrogen column density <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>H</mi></mrow></msub></math></span>, and the photon index of the powerlaw component Γ. The fittings constrain <span><math><msub><mrow><mi>N</mi></mrow><mrow><mi>H</mi></mrow></msub><mo>=</mo><mo>(</mo><mn>1.1</mn><mo>±</mo><mn>0.1</mn><mo>)</mo><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>22</mn></mrow></msup></math></span> atom cm<sup>−2</sup>, and Γ evolving from ∼2.4 in 2020 to ∼1.9 in 2022. We find the dimensionless spin parameter <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>></mo><mn>0.977</mn></math></span> <span><math><mo>(</mo><mn>3</mn><mi>σ</mi><mo>)</mo></math></span> assuming the distance of the source <span><math><mi>D</mi><mo>=</mo><mn>2.22</mn></math></span> kpc, the mass of the black hole <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub><mo>=</mo><mn>21.4</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, and the inclination of the system <span><math><mi>i</mi><mo>=</mo><msup><mrow><mn>27.47</mn></mrow><mrow><mo>∘</mo></mrow></msup></math></span>. Furthermore, considering the uncertainty of <em>D</em> from 1.22 kpc to 3.22 kpc, <span><math><mn>16</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub><mo><</mo><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub><mo><</mo><mn>25</mn><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>, <span><math><msup><mrow><mn>22</mn></mrow><mrow><mo>∘</mo></mrow></msup><mo><</mo><mi>i</mi><mo><</mo><msup><mrow><mn>31</mn></mrow><mrow><mo>∘</mo></mrow></msup></math></span>, the Monte Carlo analysis is performed and still confirms a large spin of the limitation <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>></mo><mn>0.999</mn><mo>(</mo><mn>1</mn><mi>σ</mi><mo>)</mo></math></span> without the <em>D</em>, <em>i</em>, and <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub></math></span> bias for Cygnus X-1. We also try to use the limits of <span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup></math></span> to reversely constrain the range of <em>D</em>, <em>i</em>, and <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></msub></math></span>, and find that for the extreme situation (<span><math><msup><mrow><mi>a</mi></mrow><mrow><mo>⁎</mo></mrow></msup><mo>></mo><mn>0.99</mn></math></span>), the derived distributions prefer a low <em>i</em>, large <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>BH</mi></mrow></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}
Pub Date : 2024-11-01DOI: 10.1016/j.jheap.2024.11.005
Shiladittya Debnath , Brajagopal Majumder
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.
{"title":"Neutrino emission due to pair – annihilation in the neutron star magnetic field","authors":"Shiladittya Debnath , 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 10<sup>8</sup> to 10<sup>12</sup> 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}
Pub Date : 2024-11-01DOI: 10.1016/j.jheap.2024.11.003
Himanshu Chaudhary , Ujjal Debnath , S.K. Maurya , G. Mustafa , Farruh Atamurotov
In this paper, we investigate the late-time cosmic accelerated expansion using various equations of state parametrizations within the framework of Hořava-Lifshitz gravity. We utilize Markov Chain Monte Carlo (MCMC) analysis to constrain the parameters of each proposed model, employing observational Hubble data and Type Ia supernovae. Additionally, we analyze and plot the deceleration parameters for each model. Our findings suggest that the Universe has recently transitioned from a phase of deceleration to acceleration in all the models considered. We also analyzed the behavior of the energy conditions for each proposed model within the framework of Hořava-Lifshitz gravity, specifically at the present epoch (). To further assess the effectiveness of these models, we apply both the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC) to compare their performance against the standard ΛCDM model. Our results provide valuable insights into how different models perform relative to ΛCDM, offering a comprehensive evaluation of their viability in describing the Universe's accelerated expansion.
在本文中，我们利用霍热瓦-利夫希茨引力框架内的各种状态方程参数对晚期宇宙加速膨胀进行了研究。我们利用马尔可夫链蒙特卡罗（MCMC）分析法，利用哈勃观测数据和 Ia 型超新星来约束每个拟议模型的参数。此外，我们还分析并绘制了每个模型的减速参数。我们的研究结果表明，在所有考虑的模型中，宇宙最近都从减速阶段过渡到了加速阶段。我们还分析了在霍扎瓦-利夫希茨引力框架下，每个模型的能量条件行为，特别是在当前纪元（z=0）。为了进一步评估这些模型的有效性，我们应用阿凯克信息准则（AIC）和贝叶斯信息准则（BIC）将它们的性能与标准ΛCDM模型进行了比较。我们的结果为我们了解不同模型相对于ΛCDM的表现提供了宝贵的见解，为我们全面评估这些模型在描述宇宙加速膨胀方面的可行性提供了依据。
{"title":"Constraining the equation of state parametrization in Hořava-Lifshitz gravity","authors":"Himanshu Chaudhary , Ujjal Debnath , S.K. Maurya , G. Mustafa , Farruh Atamurotov","doi":"10.1016/j.jheap.2024.11.003","DOIUrl":"10.1016/j.jheap.2024.11.003","url":null,"abstract":"<div><div>In this paper, we investigate the late-time cosmic accelerated expansion using various equations of state parametrizations within the framework of Hořava-Lifshitz gravity. We utilize Markov Chain Monte Carlo (MCMC) analysis to constrain the parameters of each proposed model, employing observational Hubble data and Type Ia supernovae. Additionally, we analyze and plot the deceleration parameters for each model. Our findings suggest that the Universe has recently transitioned from a phase of deceleration to acceleration in all the models considered. We also analyzed the behavior of the energy conditions for each proposed model within the framework of Hořava-Lifshitz gravity, specifically at the present epoch (<span><math><mi>z</mi><mo>=</mo><mn>0</mn></math></span>). To further assess the effectiveness of these models, we apply both the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC) to compare their performance against the standard ΛCDM model. Our results provide valuable insights into how different models perform relative to ΛCDM, offering a comprehensive evaluation of their viability in describing the Universe's accelerated expansion.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 427-436"},"PeriodicalIF":10.2,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656499","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}
Pub Date : 2024-10-18DOI: 10.1016/j.jheap.2024.10.011
Alison M.W. Mitchell , Silvia Celli
Supernova remnants (SNRs) are considered as the most promising source class to account for the bulk of the Galactic cosmic-ray flux. Yet amongst the population of ultra-high energy (UHE) sources that has recently emerged, due to high-altitude particle detector experiments such as LHAASO and HAWC, remarkably few are associated with known SNRs. These observations might well indicate that the highest energy particles would escape the remnant early during the shock evolution as a result of its reduced confinement capabilities. This flux of escaping particles may then encounter dense targets (gas and dust) for hadronic interactions in the form of both atomic and molecular material such as interstellar clouds, thereby generating a UHE gamma-ray flux. We explore such a scenario here, considering known SNRs in a physically driven model for particle escape, and as coupled to molecular clouds in the Galaxy. Our analysis allows the investigation of SNR-illuminated clouds in coincidence with sources detected in the first LHAASO catalogue. Indeed, the illuminated interstellar clouds may contribute to the total gamma-ray flux from several unidentified sources, as we discuss here. Yet we nevertheless find that further detailed studies will be necessary to verify or refute this scenario of passive UHE gamma-ray sources in future.
{"title":"Exploring the supernova remnant contribution to the first LHAASO source catalog via passively illuminated interstellar clouds","authors":"Alison M.W. Mitchell , Silvia Celli","doi":"10.1016/j.jheap.2024.10.011","DOIUrl":"10.1016/j.jheap.2024.10.011","url":null,"abstract":"<div><div>Supernova remnants (SNRs) are considered as the most promising source class to account for the bulk of the Galactic cosmic-ray flux. Yet amongst the population of ultra-high energy (UHE) sources that has recently emerged, due to high-altitude particle detector experiments such as LHAASO and HAWC, remarkably few are associated with known SNRs. These observations might well indicate that the highest energy particles would escape the remnant early during the shock evolution as a result of its reduced confinement capabilities. This flux of escaping particles may then encounter dense targets (gas and dust) for hadronic interactions in the form of both atomic and molecular material such as interstellar clouds, thereby generating a UHE gamma-ray flux. We explore such a scenario here, considering known SNRs in a physically driven model for particle escape, and as coupled to molecular clouds in the Galaxy. Our analysis allows the investigation of SNR-illuminated clouds in coincidence with sources detected in the first LHAASO catalogue. Indeed, the illuminated interstellar clouds may contribute to the total gamma-ray flux from several unidentified sources, as we discuss here. Yet we nevertheless find that further detailed studies will be necessary to verify or refute this scenario of passive UHE gamma-ray sources in future.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 340-355"},"PeriodicalIF":10.2,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<div><div>Current data on baryon acoustic oscillations and Supernovae of Type Ia (SNIa) cover up to <span><math><mi>z</mi><mo>∼</mo><mn>2.5</mn></math></span>. These low-redshift observations play a very important role in the determination of cosmological parameters and have been widely used to constrain the ΛCDM and models beyond the standard, such as the ones with open curvature. To extend this investigation to higher redshifts, Gamma-Ray Bursts (GRBs) stand out as one of the most promising observables. In spite of being transient, they are extremely energetic and can be used to probe the universe up to <span><math><mi>z</mi><mo>∼</mo><mn>9.4</mn></math></span>. They exhibit characteristics that suggest they are potentially standardizable candles and this allows their use to extend the distance ladder beyond SNIa. The use of GRB correlations is still a challenge due to the spread in their intrinsic properties. One of the correlations that can be employed for the standardization is the fundamental plane relation between the peak prompt luminosity, the rest-frame end time of the plateau phase, and its corresponding luminosity, also known as the <em>three-dimensional Dainotti correlation</em>. In this work, we propose an innovative method of calibration of the Dainotti relation which is independent of cosmology. We employ state-of-the-art data on Cosmic Chronometers (CCH) at <span><math><mi>z</mi><mo>≲</mo><mn>2</mn></math></span> and use the Gaussian Processes Bayesian reconstruction tool. To match the CCH redshift range, we select 20 long GRBs in the range <span><math><mn>0.553</mn><mo>≤</mo><mi>z</mi><mo>≤</mo><mn>1.96</mn></math></span> from the <em>Platinum sample</em>, which consists of well-defined GRB plateau properties that obey the fundamental plane relation. To ensure the generality of our method, we verify that the choice of priors on the parameters of the Dainotti relation and the modeling of CCH uncertainties and covariance have negligible impact on our results. Moreover, we consider the case in which the redshift evolution of the physical features of the plane is accounted for. We find that the use of CCH allows us to identify a sub-sample of GRBs that adhere even more closely to the fundamental plane relation, with an intrinsic scatter of <span><math><msub><mrow><mi>σ</mi></mrow><mrow><mi>i</mi><mi>n</mi><mi>t</mi></mrow></msub><mo>=</mo><msubsup><mrow><mn>0.20</mn></mrow><mrow><mo>−</mo><mn>0.05</mn></mrow><mrow><mo>+</mo><mn>0.03</mn></mrow></msubsup></math></span> obtained in this analysis when evolutionary effects are considered. In an epoch in which we strive to reduce uncertainties on the variables of the GRB correlations in order to tighten constraints on cosmological parameters, we have found a novel model-independent approach to pinpoint a sub-sample that can thus represent a valuable set of standardizable candles. This allows us to extend the cosmic distance ladder presenting a new catalog of calibrated luminosity distanc
{"title":"Towards a new model-independent calibration of Gamma-Ray Bursts","authors":"Arianna Favale , Maria Giovanna Dainotti , Adrià Gómez-Valent , Marina Migliaccio","doi":"10.1016/j.jheap.2024.10.010","DOIUrl":"10.1016/j.jheap.2024.10.010","url":null,"abstract":"<div><div>Current data on baryon acoustic oscillations and Supernovae of Type Ia (SNIa) cover up to <span><math><mi>z</mi><mo>∼</mo><mn>2.5</mn></math></span>. These low-redshift observations play a very important role in the determination of cosmological parameters and have been widely used to constrain the ΛCDM and models beyond the standard, such as the ones with open curvature. To extend this investigation to higher redshifts, Gamma-Ray Bursts (GRBs) stand out as one of the most promising observables. In spite of being transient, they are extremely energetic and can be used to probe the universe up to <span><math><mi>z</mi><mo>∼</mo><mn>9.4</mn></math></span>. They exhibit characteristics that suggest they are potentially standardizable candles and this allows their use to extend the distance ladder beyond SNIa. The use of GRB correlations is still a challenge due to the spread in their intrinsic properties. One of the correlations that can be employed for the standardization is the fundamental plane relation between the peak prompt luminosity, the rest-frame end time of the plateau phase, and its corresponding luminosity, also known as the <em>three-dimensional Dainotti correlation</em>. In this work, we propose an innovative method of calibration of the Dainotti relation which is independent of cosmology. We employ state-of-the-art data on Cosmic Chronometers (CCH) at <span><math><mi>z</mi><mo>≲</mo><mn>2</mn></math></span> and use the Gaussian Processes Bayesian reconstruction tool. To match the CCH redshift range, we select 20 long GRBs in the range <span><math><mn>0.553</mn><mo>≤</mo><mi>z</mi><mo>≤</mo><mn>1.96</mn></math></span> from the <em>Platinum sample</em>, which consists of well-defined GRB plateau properties that obey the fundamental plane relation. To ensure the generality of our method, we verify that the choice of priors on the parameters of the Dainotti relation and the modeling of CCH uncertainties and covariance have negligible impact on our results. Moreover, we consider the case in which the redshift evolution of the physical features of the plane is accounted for. We find that the use of CCH allows us to identify a sub-sample of GRBs that adhere even more closely to the fundamental plane relation, with an intrinsic scatter of <span><math><msub><mrow><mi>σ</mi></mrow><mrow><mi>i</mi><mi>n</mi><mi>t</mi></mrow></msub><mo>=</mo><msubsup><mrow><mn>0.20</mn></mrow><mrow><mo>−</mo><mn>0.05</mn></mrow><mrow><mo>+</mo><mn>0.03</mn></mrow></msubsup></math></span> obtained in this analysis when evolutionary effects are considered. In an epoch in which we strive to reduce uncertainties on the variables of the GRB correlations in order to tighten constraints on cosmological parameters, we have found a novel model-independent approach to pinpoint a sub-sample that can thus represent a valuable set of standardizable candles. This allows us to extend the cosmic distance ladder presenting a new catalog of calibrated luminosity distanc","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 323-339"},"PeriodicalIF":10.2,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.jheap.2024.10.008
Srijita Hazra , Vaidehi S. Paliya , A. Domínguez , C. Cabello , N. Cardiel , J. Gallego
BL Lac objects are a class of jetted active galactic nuclei that do not exhibit or have weak emission lines in their optical spectra. Recently, the first γ-ray emitting BL Lac beyond , 4FGL J1219.0 +3653 (hereafter J1219), was identified, i.e., within the first two billion years of the age of the universe. Here we report the results obtained from a detailed broadband study of this peculiar source by analyzing the new ∼58 ksec XMM-Newton and archival observations and reproducing the multiwavelength spectral energy distribution with the conventional one-zone leptonic radiative model. The XMM-Newton data revealed that J1219 is a faint X-ray emitter ( ) and exhibits a soft spectrum (0.3−10 keV photon index). By comparing the broadband physical properties of J1219 with γ-ray detected flat spectrum radio quasars (FSRQs), we have found that it has a relatively low jet power and, similar to FSRQs, the jet power is larger than the accretion disk luminosity. We conclude that deeper multiwavelength observations will be needed to fully explore the physical properties of this unique high-redshift BL Lac object.
{"title":"A multiwavelength study of the most distant gamma-ray detected BL Lacertae object 4FGL J1219.0+3653 (z = 3.59)","authors":"Srijita Hazra , Vaidehi S. Paliya , A. Domínguez , C. Cabello , N. Cardiel , J. Gallego","doi":"10.1016/j.jheap.2024.10.008","DOIUrl":"10.1016/j.jheap.2024.10.008","url":null,"abstract":"<div><div>BL Lac objects are a class of jetted active galactic nuclei that do not exhibit or have weak emission lines in their optical spectra. Recently, the first <em>γ</em>-ray emitting BL Lac beyond <span><math><mi>z</mi><mo>=</mo><mn>3</mn></math></span>, 4FGL J1219.0 +3653 (hereafter J1219), was identified, i.e., within the first two billion years of the age of the universe. Here we report the results obtained from a detailed broadband study of this peculiar source by analyzing the new ∼58 ksec <em>XMM-Newton</em> and archival observations and reproducing the multiwavelength spectral energy distribution with the conventional one-zone leptonic radiative model. The <em>XMM-Newton</em> data revealed that J1219 is a faint X-ray emitter (<span><math><msub><mrow><mi>F</mi></mrow><mrow><mn>0.3</mn><mo>−</mo><mn>10 keV</mn></mrow></msub><mo>=</mo><msubsup><mrow><mn>1.02</mn></mrow><mrow><mo>−</mo><mn>0.24</mn></mrow><mrow><mo>+</mo><mn>0.47</mn></mrow></msubsup><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>15</mn></mrow></msup></math></span> <span><math><mrow><mi>erg</mi></mrow><mspace></mspace><mspace></mspace><msup><mrow><mi>cm</mi></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup><mspace></mspace><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>) and exhibits a soft spectrum (0.3−10 keV photon index<span><math><mo>=</mo><msubsup><mrow><mn>2.28</mn></mrow><mrow><mo>−</mo><mn>0.46</mn></mrow><mrow><mo>+</mo><mn>0.58</mn></mrow></msubsup></math></span>). By comparing the broadband physical properties of J1219 with <span><math><mi>z</mi><mo>></mo><mn>3</mn></math></span> <em>γ</em>-ray detected flat spectrum radio quasars (FSRQs), we have found that it has a relatively low jet power and, similar to FSRQs, the jet power is larger than the accretion disk luminosity. We conclude that deeper multiwavelength observations will be needed to fully explore the physical properties of this unique high-redshift BL Lac object.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 290-299"},"PeriodicalIF":10.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441579","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}
Pub Date : 2024-10-16DOI: 10.1016/j.jheap.2024.10.009
J. Praveen, S.K. Narasimhamurthy
In this study, we explore the dynamics of matter bounce cosmology within the framework of Finsler-Randers geometry, focusing on the role of the Finslerian correction term . By integrating Finsler geometry into cosmological models, we introduce anisotropic effects that significantly impact the evolution of the universe, particularly during the bounce phase. The research examines various cosmological parameters, including the deceleration (), jerk (), and snap () parameters, highlighting the influence of the Finsler correction on these key indicators. Our results demonstrate that the Finslerian framework leads to more complex and abrupt transitions in the universe's expansion dynamics compared to traditional Riemannian models. The study also reveals that the Finslerian correction intensifies the violations of energy conditions, such as the null energy condition (NEC), which are crucial for the occurrence of a successful bounce. Furthermore, the analysis of the squared sound speed indicates that the model's stability is highly sensitive to the choice of the Finslerian parameters, with certain configurations leading to instability during the bounce. Our findings underscore the unique contributions of Finsler geometry to cosmological models, offering deeper insights into the behavior of the universe under anisotropic influences and providing a potential avenue for addressing longstanding challenges in cosmology.
{"title":"Matter bounce cosmology within Finsler-Randers geometry: A comprehensive study of anisotropic influences","authors":"J. Praveen, S.K. Narasimhamurthy","doi":"10.1016/j.jheap.2024.10.009","DOIUrl":"10.1016/j.jheap.2024.10.009","url":null,"abstract":"<div><div>In this study, we explore the dynamics of matter bounce cosmology within the framework of Finsler-Randers geometry, focusing on the role of the Finslerian correction term <span><math><mi>η</mi><mo>(</mo><mi>t</mi><mo>)</mo></math></span>. By integrating Finsler geometry into cosmological models, we introduce anisotropic effects that significantly impact the evolution of the universe, particularly during the bounce phase. The research examines various cosmological parameters, including the deceleration (<span><math><msub><mrow><mi>q</mi></mrow><mrow><mi>η</mi></mrow></msub><mo>(</mo><mi>t</mi><mo>)</mo></math></span>), jerk (<span><math><msub><mrow><mi>j</mi></mrow><mrow><mi>η</mi></mrow></msub><mo>(</mo><mi>t</mi><mo>)</mo></math></span>), and snap (<span><math><msub><mrow><mi>s</mi></mrow><mrow><mi>η</mi></mrow></msub><mo>(</mo><mi>t</mi><mo>)</mo></math></span>) parameters, highlighting the influence of the Finsler correction on these key indicators. Our results demonstrate that the Finslerian framework leads to more complex and abrupt transitions in the universe's expansion dynamics compared to traditional Riemannian models. The study also reveals that the Finslerian correction intensifies the violations of energy conditions, such as the null energy condition (NEC), which are crucial for the occurrence of a successful bounce. Furthermore, the analysis of the squared sound speed <span><math><msubsup><mrow><mi>v</mi></mrow><mrow><mi>s</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> indicates that the model's stability is highly sensitive to the choice of the Finslerian parameters, with certain configurations leading to instability during the bounce. Our findings underscore the unique contributions of Finsler geometry to cosmological models, offering deeper insights into the behavior of the universe under anisotropic influences and providing a potential avenue for addressing longstanding challenges in cosmology.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 300-314"},"PeriodicalIF":10.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441580","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}
Pub Date : 2024-10-16DOI: 10.1016/j.jheap.2024.10.007
Tao Wen , Yu-Hua Yao , Song-Zhan Chen , Ben-Zhong Dai , Yi-Qing Guo
The recent and brightest GRB 221009A observed by LHAASO marked the first detection of the onset of TeV afterglow, with a total of 7 GRBs exhibiting very high energy (VHE) afterglow radiation. However, consensus on VHE radiation of GRBs is still lacking. Multi-wavelength studies are currently a primary research method for investigating high-energy γ-ray astronomy. The limited sample of VHE GRBs, combined with their transient nature, hinders the progress of physical studies of GRBs. This paper aims to obtain useful information for GRB research through the properties of blazars, which share significant similarities with GRBs. By fitting high-quality and simultaneous multiwavelength spectral energy distributions with a one-zone leptonic model, the study explores the similarity of radiation properties of blazars and GRBs. A tight correlation between synchrotron and synchrotron self-Compton (SSC) emission luminosities suggests that blazars and GRBs share similar radiation mechanisms, to be specific, synchrotron radiation produces the observed X-ray photons, which also serve as targets for electrons in the SSC process. We hope that ground-based experiments can observe more GRBs in sub-TeV to confirm these findings.
最近由LHAASO观测到的最亮的GRB 221009A标志着首次探测到TeV余辉的开始，总共有7个GRB表现出极高能（VHE）余辉辐射。然而，人们对 GRB 的 VHE 辐射仍然缺乏共识。多波长研究是目前研究高能γ射线天文学的主要方法。VHE GRBs 样本有限，加之其瞬态性质，阻碍了 GRBs 物理研究的进展。本文旨在通过与 GRBs 有着显著相似性的类星体的特性来获取对 GRB 研究有用的信息。通过用单区轻子模型拟合高质量的多波长同步光谱能量分布，该研究探索了类星体和古雷暴暴的辐射特性的相似性。同步加速器和同步加速器自康普顿（SSC）发射光度之间的紧密相关性表明，蓝星和GRB具有相似的辐射机制，具体来说，同步加速器辐射产生了观测到的X射线光子，而X射线光子也是SSC过程中电子的目标。我们希望地面实验能够观测到更多的亚天文单位的GRB，以证实这些发现。
{"title":"A universal energy relation between synchrotron and synchrotron self-Compton radiation in GRBs and blazars","authors":"Tao Wen , Yu-Hua Yao , Song-Zhan Chen , Ben-Zhong Dai , Yi-Qing Guo","doi":"10.1016/j.jheap.2024.10.007","DOIUrl":"10.1016/j.jheap.2024.10.007","url":null,"abstract":"<div><div>The recent and brightest GRB 221009A observed by LHAASO marked the first detection of the onset of TeV afterglow, with a total of 7 GRBs exhibiting very high energy (VHE) afterglow radiation. However, consensus on VHE radiation of GRBs is still lacking. Multi-wavelength studies are currently a primary research method for investigating high-energy <em>γ</em>-ray astronomy. The limited sample of VHE GRBs, combined with their transient nature, hinders the progress of physical studies of GRBs. This paper aims to obtain useful information for GRB research through the properties of blazars, which share significant similarities with GRBs. By fitting high-quality and simultaneous multiwavelength spectral energy distributions with a one-zone leptonic model, the study explores the similarity of radiation properties of blazars and GRBs. A tight correlation between synchrotron and synchrotron self-Compton (SSC) emission luminosities suggests that blazars and GRBs share similar radiation mechanisms, to be specific, synchrotron radiation produces the observed X-ray photons, which also serve as targets for electrons in the SSC process. We hope that ground-based experiments can observe more GRBs in sub-TeV to confirm these findings.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 315-322"},"PeriodicalIF":10.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444817","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}
Pub Date : 2024-10-10DOI: 10.1016/j.jheap.2024.10.005
M. Zubair , Quratulien Muneer , Saira Waheed , G. Dilara Açan Yildiz , Ertan Gudekli
Exploration of bouncing cosmic models in modified theories has gained much popularity in modern cosmology. This paper explores the Lagrangian function of a new theory namely framework by taking four renowned cosmic bouncing models, i.e., the exponential bounce, oscillatory bounce scenario, power law, and matter bouncing. Our primary objective is to fix the form of function for each model and investigate which kinds of reconstructed Lagrangian function have potential of regenerating bouncing scenario in terms of analytical form. It is seen that except power law model, the analytical solutions are conceivable only for certain cases of these bouncing models. For power law bounce, different cases of Lagrangian function may be rebuilt analytically while for some other bouncing scenarios, it is found that particular solutions are not always attainable and hence only the complimentary solutions can be explored. Further, we examine the behavior of energy constraints and stability of these analytically formed bouncing solutions. Additionally, we determine that the dark energy phase in gravity is compatible with the experimental data of BAO+Sne-Ia+CMB+H(z) and it is shown that cosmic bounce can be produced with dark energy eras in this gravity. We also present some constraints on the model parameters with Hubble parameter values and ΛCDM to determine the best-fit values of model via least square and reduced chi-squares methods. It is concluded that matter bounce model is the best fitted with the observational data set as well as ΛCDM model because it has least value of .
{"title":"Bouncing universe scenarios in an extended gravitational framework involving curvature-matter coupling","authors":"M. Zubair , Quratulien Muneer , Saira Waheed , G. Dilara Açan Yildiz , Ertan Gudekli","doi":"10.1016/j.jheap.2024.10.005","DOIUrl":"10.1016/j.jheap.2024.10.005","url":null,"abstract":"<div><div>Exploration of bouncing cosmic models in modified theories has gained much popularity in modern cosmology. This paper explores the Lagrangian function of a new theory namely <span><math><mi>F</mi><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>,</mo><mi>T</mi><mo>)</mo></math></span> framework by taking four renowned cosmic bouncing models, i.e., the exponential bounce, oscillatory bounce scenario, power law, and matter bouncing. Our primary objective is to fix the form of <span><math><mi>F</mi><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>,</mo><mi>T</mi><mo>)</mo></math></span> function for each model and investigate which kinds of reconstructed Lagrangian function have potential of regenerating bouncing scenario in terms of analytical form. It is seen that except power law model, the analytical solutions are conceivable only for certain cases of these bouncing models. For power law bounce, different cases of Lagrangian function may be rebuilt analytically while for some other bouncing scenarios, it is found that particular solutions are not always attainable and hence only the complimentary solutions can be explored. Further, we examine the behavior of energy constraints and stability of these analytically formed bouncing solutions. Additionally, we determine that the dark energy phase in <span><math><mi>F</mi><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>,</mo><mi>T</mi><mo>)</mo></math></span> gravity is compatible with the experimental data of BAO+Sne-Ia+CMB+H(z) and it is shown that cosmic bounce can be produced with dark energy eras in this gravity. We also present some constraints on the model parameters with Hubble parameter values and ΛCDM to determine the best-fit values of model via least square and reduced chi-squares methods. It is concluded that matter bounce model is the best fitted with the observational data set as well as ΛCDM model because it has least value of <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mi>m</mi></mrow><mrow><mn>2</mn></mrow></msubsup></math></span>.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"44 ","pages":"Pages 243-265"},"PeriodicalIF":10.2,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433060","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}
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