Journal of High Energy Astrophysics最新文献

{"title":"Thermal instability of thin disk in the presence of wind and corona","authors":"Arezoo Tajmohamadi ,&nbsp;Shahram Abbassi","doi":"10.1016/j.jheap.2025.01.018","DOIUrl":"10.1016/j.jheap.2025.01.018","url":null,"abstract":"<div><div>This study investigates the thermal stability of thin accretion disks in high-energy astrophysical systems, incorporating the effects of magnetic fields, winds, and coronae. We analyze how these factors influence disk stability, focusing on conditions under which magnetic fields enhance stability and on scenarios where winds and coronae can either stabilize or destabilize the disk. Our results reveal that increasing corona parameters raises disk thickness and reduces temperature, thereby affecting gas, radiation, and magnetic pressures. These interactions underscore the complex dependencies that shape accretion disk dynamics, offering insights into their structural and thermal behavior under varying physical conditions. The findings contribute to advancing theoretical models and numerical simulations of accretion processes in environments such as active galactic nuclei (AGN) and X-ray binaries, where disk stability plays a critical role in observed emissions and variability patterns.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"46 ","pages":"Article 100346"},"PeriodicalIF":10.2,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175922","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":"Shadow images of Ghosh-Kumar rotating black hole illuminated by spherical light sources and thin accretion disks","authors":"Chen-Yu Yang ,&nbsp;M. Israr Aslam ,&nbsp;Xiao-Xiong Zeng ,&nbsp;Rabia Saleem","doi":"10.1016/j.jheap.2025.01.017","DOIUrl":"10.1016/j.jheap.2025.01.017","url":null,"abstract":"<div><div>This study investigates the astronomical implications of the Ghosh-Kumar rotating Black Hole (BH), particularly its behaviour on shadow images, illuminated by celestial light sources and equatorial thin accretion disks. Our research delineates a crucial correlation between dynamics of the shadow images and the parameters <em>a</em>, <em>q</em> and the <span><math><msub><mrow><mi>θ</mi></mrow><mrow><mi>o</mi><mi>b</mi><mi>s</mi></mrow></msub></math></span>, which aptly reflect the influence of the model parameters on the optical features of shadow images. Initially, elevated behaviour of both <em>a</em> and <em>q</em> transforms the geometry of the shadow images from perfect circles to an oval shape and converges them towards the centre of the screen. By imposing the backward ray-tracing method, we demonstrate the optical appearance of shadow images of the considering BH space-time in the celestial light source. The results demonstrate that the Einstein ring shows a transition from an axisymmetric closed circle to an arc-like shape on the screen as well as producing the deformation on the shadow shape with the modifications of space-time parameters at the fixed observational position. Next, we observe that the attributes of accretion disks along with the relevant parameters on the shadow images are illuminated by both prograde and retrograde accreting flow. Our study reveals the process by which the accretion disk transitions from a disk-like structure to a hat-like shape with the aid of observational angles. Moreover, with an increase of <em>q</em>, the observed flux of both direct and lensed images of the accretion disk gradually moves towards the lower zone of the screen. Furthermore, we present the intensity distribution of the red-shift factors on the screen. Our analysis suggests that the observer can see both red-shift and blue-shift factors on the screen at higher observational angles, while augmenting the values of both <em>a</em> and <em>q</em>, enhancing the effect of red-shift on the screen.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"46 ","pages":"Article 100345"},"PeriodicalIF":10.2,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143175921","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":"Spectro-temporal investigation of quasi-periodic oscillations from black hole X-ray binary 4U 1630-472 using NICER","authors":"Ansh Chopra ,&nbsp;Manoneeta Chakraborty ,&nbsp;Unnati Kashyap","doi":"10.1016/j.jheap.2025.01.016","DOIUrl":"10.1016/j.jheap.2025.01.016","url":null,"abstract":"<div><div>We present a comprehensive analysis of the spectro-temporal characteristics of the X-ray variabilities from black hole X-ray binary 4U 1630–472 during its three outbursts (2018, 2020, and 2021) as observed by <em>NICER</em>. We detected 27 Quasi-Periodic Oscillations (QPOs), out of which 25 were observed during the 2021 outburst. In this study, we specifically focus on the relationship between spectral and timing parameters and the frequency of type-C QPOs in the 2021 outburst of the black hole binary 4U 1630–472 during its rising phase. We found strong correlations between the photon index of the non-thermal emission and the QPO frequency. We also observed a critical frequency at ∼ 2.31 Hz, above which the behavior of the Q-factor of the QPO changed significantly with the QPO frequency. We further identified two events characterized by a surge in the total flux, corresponding to the disappearance of type-C QPOs. Although the first event appeared like an X-ray flare, during the second event, the source reached a state with a total flux higher than 10⁻⁸ erg/cm²/s and exhibited a different type of QPO with lower frequencies and weaker amplitudes. We compare our results with the previously reported QPO characteristics for black hole outbursts and discuss the various models that could interpret the critical frequency and potentially explain the origin and evolution of these type-C QPOs.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"46 ","pages":"Article 100344"},"PeriodicalIF":10.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577626","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":"Probing spectral evolution and intrinsic variability of Mkn 421: A multi-epoch AstroSat study of X-ray spectra","authors":"Sikandar Akbar ,&nbsp;Zahir Shah ,&nbsp;Ranjeev Misra ,&nbsp;Naseer Iqbal ,&nbsp;Javaid Tantry","doi":"10.1016/j.jheap.2025.01.009","DOIUrl":"10.1016/j.jheap.2025.01.009","url":null,"abstract":"<div><div>Our study presents a time-resolved X-ray spectral analysis of Mkn<!--> <!-->421, using AstroSat observations taken during different epochs between 2016 and 2019. The variability of the source in X-rays is utilized to investigate the evolution of its spectral properties. Each observation period was divided into segments of about 10 ks, and we employed three forms of particle distributions like broken-power law (BPL), log-parabola (LP), and power-law with maximum electron energy (<span><math><mi>ξ</mi><mo>−</mo><mi>m</mi><mi>a</mi><mi>x</mi></math></span> model) undergoing synchrotron losses to fit the broad X-ray spectrum in each segment. We observed that all of these models provided good fit to the spectra. In case of broken-power law model, we investigated the relationship between normalized particle density at an energy less than the break energy and the index before the break. The results revealed an inverse correlation between the index and particle density with no time delay. Additionally, correlations between spectral parameters were used to determine the pivot energy. We observed that the pivot energy remained same across the observations. For <span><math><mi>ξ</mi><mo>−</mo><mi>m</mi><mi>a</mi><mi>x</mi></math></span> and LP model, we define analogous pivot energies and show that they also do not vary, indicating the model independent nature of the result. The constant pivot energy suggests that the source's variability arises from index variations and not due to changes in the normalization. Consequently, parameters such as magnetic field strength, doppler factor etc may not contribute to the source's variability. Instead, variations are primarily associated with the acceleration or escape timescales of emitted particles within the source.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 438-455"},"PeriodicalIF":10.2,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162961","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":"A white dwarf binary candidate discovered by LAMOST using dynamical method","authors":"Haifan Zhu ,&nbsp;Wei Wang ,&nbsp;Xue Li ,&nbsp;Jia-jia Li ,&nbsp;Pengfu Tian","doi":"10.1016/j.jheap.2025.01.015","DOIUrl":"10.1016/j.jheap.2025.01.015","url":null,"abstract":"<div><div>We present the discovery of a binary system containing a white dwarf candidate using data from the LAMOST. Our analysis of the radial velocity data allowed us to determine an orbital period of approximately 0.953 days and a mass function of 0.129 <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span>. Through spectral energy distribution (SED) fitting, we obtained the stellar parameters of the visible star. By combining these results with the mass function, we established a relationship between the mass of the invisible star and the system's inclination angle, along with the Roche lobe radius. We find that the mass of the invisible star is below the Chandrasekhar limit when the inclination angle exceeds <span><math><msup><mrow><mn>35</mn></mrow><mrow><mo>∘</mo></mrow></msup></math></span>. Given that systems with large variations in radial velocity typically have high inclination angles, we classify the invisible star as a white dwarf candidate. The Roche lobe radius exceeds the physical radius of the visible star, indicating that no mass transfer occurs, which results in a weak ellipsoidal modulation effect. Additionally, we obtained light curves from the TESS, ASAS-SN, and CRTS surveys. The light curves also exhibit a periodicity of approximately 0.95 days, with ellipsoidal modulation only in the 2019 TESS observations. Coupled with the strong <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span> emission line observed in the LAMOST MRS spectrum, we infer that the surface of the visible star contains significant hot spots. This obscures the system's inherently weak ellipsoidal modulation, resulting in a manifestation of rotational variables. Furthermore, an analysis of the dynamical characteristics of this system indicates that it has a high inclination angle (&gt;60 degrees) and its orbital properties are consistent with those of typical thin disk stars, supporting the hypothesis that the invisible object is a white dwarf.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 428-437"},"PeriodicalIF":10.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162960","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":"Gamma ray flares from active region within inhomogeneous AGN jet","authors":"A. Śmiałkowski,&nbsp;W. Bednarek","doi":"10.1016/j.jheap.2025.01.012","DOIUrl":"10.1016/j.jheap.2025.01.012","url":null,"abstract":"<div><div>Two stages of non-thermal emission from relativistic jets in active galaxies can be distinguished: a low level persistent emission and a high level variable emission. It has been recently proposed that both stages are produced in the inner (parsec scale) jet region where electrons are accelerated to TeV energies. We consider a scenario in which the low-level persistent emission originates in the extended, parsec-scale jet but the high level emission is produced by electrons accelerated in a localized region within the inner jet. Our aim is to calculate self-consistently the non-thermal emission expected from the AGN jet in different radiation stages. Then, we will be able to model different emission stages observed in blazars in terms of a single scenario. We modify the stationary, non-local, inhomogeneous AGN jet model for the stationary jet emission by introducing a small active region within the stationary jet, whose physical parameters differ significantly from those in the extended large-scale jet. We distinguish four different emission components which are due to the interaction of relativistic electrons in the active region with the radiation from the active region and radiation from the extended jet and also due to the electrons in the extended jet, which comptonize synchrotron radiation from the extended jet and the active region. Depending on the nature of the active region, we are able to explain the appearance of different types of emission levels in BL Lac type blazars, i.e. the high states observed only in the X-rays or only in the <em>γ</em>-rays. Moreover, we predict the existence of a new type of high emission state in BL Lacs, so called the orphan MeV-soft synchrotron state, in which the inverse Compton emission is mainly limited to the MeV energy range. Such type of blazars have not been observed up to now due to the limited sensitivity of telescopes in the MeV energy range.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 456-462"},"PeriodicalIF":10.2,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162959","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":"Modelling the energy dependent X-ray variability of Mrk 335","authors":"K. Akhila ,&nbsp;Ranjeev Misra ,&nbsp;Rathin Sarma ,&nbsp;Savithri H. Ezhikode ,&nbsp;K. Jeena","doi":"10.1016/j.jheap.2025.01.014","DOIUrl":"10.1016/j.jheap.2025.01.014","url":null,"abstract":"<div><div>We present a technique which predicts the energy dependent fractional r.m.s. for linear correlated variations of a pair of spectral parameters and apply it to an <em>XMM-Newton</em> observation of Mrk 335. The broadband X-ray spectrum can be interpreted as a patchy absorber partially covering the primary emission, a warm and hot coronal emission or a relativistically blurred reflection along with the primary emission. The fractional r.m.s. has a non-monotonic behaviour with energy for segments of lengths 3 and 6 ksecs. For each spectral model, we consider every pair of spectral parameters and fit the predicted r.m.s. with the observed ones, to get the pair which provides the best fit. We find that a variation in at least two parameters is required for all spectral interpretations. For both time segments, variations in the covering fraction of the absorber and the primary power law index gives the best result for the partial covering model, while a variation in the normalization and spectral index of the warm component gives the best fit in the two corona interpretation. For the reflection model, the best fit parameters are different for the two time segment lengths, and the results suggests that more than two parameters are required to explain the data. This, combined with the extreme values of emissivity index and reflection fraction parameters obtained from the spectral analysis, indicates that the blurred reflection model might not be a suitable explanation for the Mrk 335 spectrum. We discuss the results as well as the potential of the technique to be applied to other data sets of different AGN.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 418-427"},"PeriodicalIF":10.2,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102962","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":"Insights into f(Q) gravity: Modeling through deceleration parameter","authors":"S.A. Narawade,&nbsp;B. Mishra","doi":"10.1016/j.jheap.2025.01.013","DOIUrl":"10.1016/j.jheap.2025.01.013","url":null,"abstract":"<div><div>In this paper, we have reconstructed <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> gravity cosmological models with the novel forms of the deceleration parameter. The parameters are constrained by incorporating the cosmological datasets from Hubble parameter, Type Ia Supernovae and Baryon Acoustic Oscillations. We have examined two parametrizations of the deceleration parameter and fit them into the models through Monte Carlo Markov Chain (MCMC) analysis, one with the power-law function and the other one with the logarithmic function. The Power-law model exhibits strong agreement with higher <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> values, aligning well with recent <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> measurements, whereas the logarithmic model achieves lower matter density constraints. Both the models successfully recover observationally consistent estimates for the Hubble constant <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> and matter density <span><math><msub><mrow><mi>Ω</mi></mrow><mrow><msub><mrow><mi>m</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></msub></math></span>, though with varying degrees of precision and alignment with the ΛCDM as a limit. These two models are used to reconstruct the <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> function for each case, yielding analytical expressions that closely align with the numerical solutions. Statistical comparisons using Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) reveal a competitive performance with the ΛCDM model and positioning these <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> models as promising alternatives to explain late time cosmic phenomena.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 409-417"},"PeriodicalIF":10.2,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102418","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":"Greybody factor and accretion disk around regular black holes in Verlinde emergent gravity","authors":"Shahid Chaudhary ,&nbsp;Muhammad Danish Sultan ,&nbsp;Adnan Malik ,&nbsp;Asifa Ashraf ,&nbsp;Yousef Mohammad Alanazi ,&nbsp;Abdulrahman Bin Jumah ,&nbsp;Ali M. Mubaraki","doi":"10.1016/j.jheap.2025.01.011","DOIUrl":"10.1016/j.jheap.2025.01.011","url":null,"abstract":"<div><div>Verlinde's emergent gravity (VEG) posits that gravity is not a fundamental force but an emergent phenomenon arising from the entropic nature of spacetime. Building on this concept, recent research has introduced a novel class of black holes within the VEG framework, linking the effects of apparent dark matter to baryonic matter distributions. In this study, we investigate the greybody factors and accretion disk properties around a Simpson–Visser Minkowski core black hole solution in VEG. We derive the effective potential and rigorous bounds for this black hole model, showing that various model parameters significantly influence both the effective potential and greybody factor bounds. Notably, increasing parameters associated with emergent gravity heightens the peak of the effective potential while reducing greybody factor bounds, offering insights into how VEG modifies black hole radiation. Through detailed density plots, we highlight potential observational signatures that could distinguish black holes governed by emergent gravity from those predicted by traditional theories. Using the established Novikov-Thorne model, we explore thin accretion disks around this unique black hole solution, uncovering a strong correlation between disk dynamics and VEG parameters. Our results indicate that VEG induces vertical stretching and outward expansion in the accretion disk structure. We present a comprehensive analysis of the accretion disk by examining both direct and secondary images at varying radial distances and observational angles, offering new perspectives on how emergent gravity influences observable black hole environments.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"46 ","pages":"Article 100339"},"PeriodicalIF":10.2,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577627","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":"Dark matter admixed neutron stars with a realistic nuclear equation of state from chiral nuclear interactions","authors":"Domenico Scordino ,&nbsp;Ignazio Bombaci","doi":"10.1016/j.jheap.2025.01.008","DOIUrl":"10.1016/j.jheap.2025.01.008","url":null,"abstract":"<div><div>We study the effects of dark matter on the structural properties of neutron stars. In particular we investigate how the presence of a dark matter component influences the mass-radius relation, the value of the maximum mass of a neutron star and other stellar properties. To model ordinary matter we use a state-of-the-art equation of state of <em>β</em>-stable nuclear matter obtained using the Brueckner-Hartree-Fock quantum many-body approach starting from two-body and three-body nuclear interactions derived from chiral effective field theory. The dark matter component of the star is modeled as a non-self-annihilating system of spin 1/2 fermions at zero temperature and its equation of state as an ideal relativistic Fermi gas. The equilibrium configurations of these dark matter admixed neutron stars (DANS) are calculated by solving a generalization of the Tolman-Oppenheimer-Volkoff equations to the case where the system consists of two perfect fluids interacting solely through gravity. We find that, depending on the dark matter particle mass <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>χ</mi></mrow></msub></math></span>, one can have somehow opposite effects on the stellar properties. In the case <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>χ</mi></mrow></msub><mo>=</mo><mn>1</mn><mspace></mspace><mtext>GeV</mtext></math></span>, the stellar gravitational maximum mass <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span> decreases, whereas in the case <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>χ</mi></mrow></msub><mo>=</mo><mn>0.1</mn><mspace></mspace><mtext>GeV</mtext></math></span>, <span><math><msub><mrow><mi>M</mi></mrow><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span> increases with respect to the maximum mass of ordinary neutron stars. We also show that the presence of dark matter has indirect sizable effect on the proton fraction in the ordinary matter fluid and, in the case <span><math><msub><mrow><mi>m</mi></mrow><mrow><mi>χ</mi></mrow></msub><mo>=</mo><mn>1</mn><mspace></mspace><mtext>GeV</mtext></math></span>, results in a decrease of the threshold gravitational mass <span><math><msubsup><mrow><mi>M</mi></mrow><mrow><mi>t</mi><mi>o</mi><mi>t</mi></mrow><mrow><mi>d</mi><mi>u</mi><mi>r</mi><mi>c</mi><mi>a</mi></mrow></msubsup></math></span> for having direct URCA processes and fast stellar cooling. Finally we study the stability of dark matter admixed neutron stars with respect to radial perturbations.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 371-381"},"PeriodicalIF":10.2,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102417","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}