Journal of High Energy Astrophysics最新文献

{"title":"On the duration of gamma-ray bursts","authors":"Bing Zhang","doi":"10.1016/j.jheap.2024.12.013","DOIUrl":"10.1016/j.jheap.2024.12.013","url":null,"abstract":"<div><div>Recently, a short-duration GRB with supernova association (GRB 200826A) and two long-duration GRBs with kilonova associations (GRB 211211A and GRB 230307A) have been detected, which demolished the hope for a tidy connection between GRB duration with their progenitor systems. Here I summarize various physical factors that can shape the duration of a GRB and propose that the duration of a GRB can be defined by four factors: progenitor, central engine, emitter, and geometry. The progenitor-defined duration is only relevant when the central engine is powered by accretion and when the modifications by other factors are not important. The untidy situation of duration - progenitor mismatches suggests that other factors likely play important roles in defining GRB duration at least in some GRBs. In particular, a GRB may not be powered by accretion but rather by a millisecond magnetar at least for some GRBs. The complicated lightcurve of GRB 211211A suggests both progenitor- and engine-defined durations, which may require a new type of progenitor system involving a white dwarf - neutron star merger with a magnetar merger product. The single broad pulse lightcurve with well-behaved energy-dependent behavior of GRB 230307A suggests an emitter-defined long duration. The central engine timescale may be short enough to be accommodated within the framework of a standard binary neutron star merger. Its spiky lightcurve with fast variability as well as extended X-ray emission suggest the existence of mini-jets in the global dissipation region, powered by an underlying magnetar.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 325-332"},"PeriodicalIF":10.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102420","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":"Particle dynamics and quasi-periodic oscillations in the Dyonic ModMax: Constraint using quasars data","authors":"Husanboy Hoshimov ,&nbsp;Akbar Davlataliev ,&nbsp;Farruh Atamurotov ,&nbsp;Ahmadjon Abdujabbarov ,&nbsp;Ali Övgün","doi":"10.1016/j.jheap.2024.12.012","DOIUrl":"10.1016/j.jheap.2024.12.012","url":null,"abstract":"<div><div>In this work, we have worked out dynamical aspects for the particles moving in the Dyonic Mod Max spacetime. We have calculated the innermost stable circular orbit (ISCO) around black hole in Dyonic Mod Max and explored its implications for different microquasars. Considering the Dyonic Mod Max black hole as a microquasar source, we have studied quasi-periodic oscillation (QPO) around such a black hole. Finally, we determine constraint values for the parameters <em>Q</em> and <em>γ</em> in the Dyonic ModMax spacetime by analyzing QPOs observed from the quasars GRO J1655–40, XTE J1550–564, XTE J1859+226, GRS 1915+105, and H1743-322. We use the Monte Carlo Markov Chain (MCMC) method to analyze the observational data, which helps us refine these parameters and better understand the behavior of black holes in the Dyonic ModMax model.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 306-315"},"PeriodicalIF":10.2,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102767","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":"Static, spherically symmetric solutions in f(Q)-gravity and in nonmetricity scalar-tensor theory","authors":"Nikolaos Dimakis ,&nbsp;Petros A. Terzis ,&nbsp;Andronikos Paliathanasis ,&nbsp;Theodosios Christodoulakis","doi":"10.1016/j.jheap.2024.12.011","DOIUrl":"10.1016/j.jheap.2024.12.011","url":null,"abstract":"<div><div>We solve the gravitational field equations for a static, spherically symmetric spacetime within the framework of the symmetric teleparallel theory of gravity. Specifically, we derive new solutions within the context of power-law <span><math><mi>f</mi><mo>(</mo><mi>Q</mi><mo>)</mo></math></span> gravity and the nonmetricity scalar-tensor theory. For the connection in the non-coincidence gauge, we present the point-like Lagrangian that describes the employed field equations. Furthermore, we construct two conservation laws, and for different values of these conserved quantities, we analytically solve the gravitational field equations. New solutions are obtained, we investigate their physical properties and their general relativistic limit. Finally, we discuss the algebraic properties for the derived spacetimes.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 273-289"},"PeriodicalIF":10.2,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102790","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":"NuSTAR and NICER observations of X Persei","authors":"Binay Rai,&nbsp;Mohammed Tobrej,&nbsp;Manoj Ghising,&nbsp;Bikash Chandra Paul","doi":"10.1016/j.jheap.2024.12.009","DOIUrl":"10.1016/j.jheap.2024.12.009","url":null,"abstract":"<div><div>We have studied the timing and spectral properties of the persistent Be/X-ray pulsar namely, X Persei using the <em>NuSTAR</em> and <em>NICER</em> observations of 2019. The pulsar is continuously in spin-up phase since 2003 with a spin-up rate of ∼(-3.18±0.04)×10⁻⁴ <span><math><mi>y</mi><msup><mrow><mi>r</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. A broadband 0.7-79 keV energy spectral fitting is performed using <em>NuSTAR</em> and <em>NICER</em> observations. It is found that the two component model considered here fits the spectrum more satisfactorily than the single-component model. An additional <span>gabs</span> model was used to fit an absorption-like feature found in the residuals of the spectrum fitted by the two components model. We interpret the absorption-like feature in the spectrum with a cyclotron line as reported in the literature. The centroid energy of the absorption-like feature is found to lie in the energy range of 32.5- 36.0 keV. The absorption feature found here is independent of the models used in fitting the spectrum. The broadband spectrum is also fitted making use of the physical bulk and thermal Comptonization model suggesting that thermal Comptonization dominates over bulk Comptonization.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 265-272"},"PeriodicalIF":10.2,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102789","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":"Detection of polarized Fermi-bubble synchrotron and dust emission","authors":"Uri Keshet","doi":"10.1016/j.jheap.2024.12.010","DOIUrl":"10.1016/j.jheap.2024.12.010","url":null,"abstract":"<div><div>The elusive polarized microwave signal from the Fermi bubbles is disentangled from the more extended polarized lobes, which similarly emanate from the Galactic plane but stretch farther west of the bubbles. The projected <span><math><mo>∼</mo><mn>20</mn><mtext>%</mtext></math></span> synchrotron polarization reveals magnetic fields preferentially parallel to the bubble edges, as expected downstream of a strong shock. The projected <span><math><mo>∼</mo><mn>20</mn><mtext>%</mtext></math></span> polarization of thermal dust emission is similarly oriented, constraining grain alignment in an extreme environment. We argue that the larger lobes arise from an older Galactic-center, likely supermassive black-hole, outburst.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 299-305"},"PeriodicalIF":10.2,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102792","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 doublet of cosmological models to challenge the H0 tension in the Pantheon Supernovae Ia catalog","authors":"B. De Simone ,&nbsp;M.H.P.M. van Putten ,&nbsp;M.G. Dainotti ,&nbsp;G. Lambiase","doi":"10.1016/j.jheap.2024.12.003","DOIUrl":"10.1016/j.jheap.2024.12.003","url":null,"abstract":"<div><div>ΛCDM provides a leading framework in the interpretation of modern cosmology. Nevertheless, the scientific community still struggles with many open problems in cosmology. Among the most noticeable ones, the tension in the Hubble constant <em>H</em>₀ is particularly intriguing, prompting a wide range of possible solutions. In the present work, the flat scale-free cosmology (<em>S</em> CDM) of Maeder (2017) is tested for <em>H</em>₀ tension in fits to the Pantheon sample of Supernovae Ia. The Pantheon sample is a collection of 1048 SNe Ia, which formally defines <em>H</em>₀ = <em>H</em>(0) by extrapolation to redshift zero of data over positive redshifts <em>z</em> &gt; 0. Here, we consider <em>H</em>_0,<em>_k</em> in fits of <em>S</em> CDM over <em>k</em> equally sized bins of sub-samples of mean redshift <em>z_k</em>. To quantify a trend in <em>H</em>_0,<em>_k</em> with <em>z_k</em>, the results are fit by <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow><mo>=</mo><msup><mrow><mrow><msubsup><mi>H</mi><mn>0</mn><mo>′</mo></msubsup><mo>/</mo><mrow><mo>(</mo><mrow><mn>1</mn><mo>+</mo><mi>z</mi></mrow><mo>)</mo></mrow></mrow></mrow><mi>α</mi></msup></mrow></math></span> in the two parameters <span><math><msubsup><mi>H</mi><mn>0</mn><mo>′</mo></msubsup></math></span> and α. This approach tests for model imperfections or data biases by trends that are inconsistent with zero. Our findings show a decreasing trend inconsistent with zero at 5.3σ significance, significantly more so than in ΛCDM. These results are further confirmed in Pantheon+. It appears that a solution to <em>H</em>₀ tension is to be found in models with a deceleration parameter <em>q</em>₀ &lt; <em>q</em>_0,Λ below that of ΛCDM, rather than <em>q</em>_0,Λ &lt; <em>q</em>_0,<em>_S</em> &lt; 0 satisfied by <em>S</em> CDM.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 290-298"},"PeriodicalIF":10.2,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102791","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}

{"title":"Quantum Gravitational Atoms as New Matter: A chance of Hydrogen with Primordial Black Hole Nuclei?","authors":"Elio Quiroga Rodríguez","doi":"10.1016/j.jheap.2024.12.008","DOIUrl":"10.1016/j.jheap.2024.12.008","url":null,"abstract":"<div><div>In this study, the author examines the theoretical properties of a hypothetical hydrogen-like atom composed of a primordial black hole (PBH) nucleus, called <em>PBH<img>H protoatoms.</em></div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 262-264"},"PeriodicalIF":10.2,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102788","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":"Comprehensive spectro-temporal studies of GX 17+2 using AstroSat observations","authors":"Neal Titus Thomas,&nbsp;S. Lavanya,&nbsp;S.B. Gudennavar,&nbsp;S.G. Bubbly","doi":"10.1016/j.jheap.2024.12.007","DOIUrl":"10.1016/j.jheap.2024.12.007","url":null,"abstract":"<div><div>We performed a comprehensive spectro-temporal study of the Z-type neutron star low-mass X-ray binary GX 17+2 using long term data from the <em>AstroSat</em>/Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC). The hardness–intensity diagrams (HIDs) of the source revealed a positive correlation between the hardness and intensity, characteristic of soft spectral state. Additionally, the LAXPC-20 HID showed the presence of secular shifts in both hardness and intensity. Time-averaged spectral modelling in the 0.7 − 30.0 keV energy range indicated that the spectra could be well fitted with the model combination: <span>constant</span> × <span>edge</span> × <span>edge</span> × <span>tbabs</span> × <span>thcomp</span> × <span>bbodyrad</span>. This analysis yielded a blackbody radius (<span><math><msub><mrow><mi>R</mi></mrow><mrow><mi>b</mi><mi>b</mi></mrow></msub></math></span>) of ∼59 km, photon index (Γ) of ∼2.84 and electron temperature (<span><math><mi>k</mi><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi></mrow></msub></math></span>) of ∼4.84 keV. Time-averaged temporal analysis revealed normal branch oscillations (NBOs) at ∼ 7 Hz in Observations 1 and 3, flaring branch oscillation (FBO) at ∼15 Hz in Observation 2, and horizontal branch oscillation (HBO) at ∼36 Hz in Observation 5. Flux resolved spectro-temporal analysis indicated that the source remained in the soft spectral state throughout all observations. A positive correlation was observed between <span><math><mi>k</mi><msub><mrow><mi>T</mi></mrow><mrow><mi>b</mi><mi>b</mi></mrow></msub></math></span>, <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>b</mi><mi>b</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>b</mi><mi>o</mi><mi>l</mi></mrow></msub></math></span>, whereas an anti-correlation was noted between <span><math><mi>k</mi><msub><mrow><mi>T</mi></mrow><mrow><mi>e</mi></mrow></msub></math></span> and <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>b</mi><mi>o</mi><mi>l</mi></mrow></msub></math></span>. The constant frequency of NBOs with an increase in <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>b</mi><mi>o</mi><mi>l</mi></mrow></msub></math></span> suggests that their origin lies in a region strongly influenced by the corona, as explained by the radiation-hydrodynamic model. The origin of FBOs may be attributed to the damped radiation-hydrodynamic mode of radial flow, while the origin of HBOs is supported by the beat-frequency model.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 250-261"},"PeriodicalIF":10.2,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102787","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":"Effect of baryon number density (n) on the maximum mass and stability of strange stars","authors":"Anusmita Nag,&nbsp;Debadri Bhattacharjee,&nbsp;Koushik Ballav Goswami,&nbsp;Pradip Kumar Chattopadhyay","doi":"10.1016/j.jheap.2024.12.005","DOIUrl":"10.1016/j.jheap.2024.12.005","url":null,"abstract":"<div><div>A new class of relativistic solutions of Einstein field equations for an anisotropic strange star admitting the Vaidya-Tikekar type metric potential in the framework of MIT bag model equation of state of the strange matter, <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>r</mi></mrow></msub><mo>=</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>3</mn></mrow></mfrac><mo>(</mo><mi>ρ</mi><mo>−</mo><mn>4</mn><mi>B</mi><mo>)</mo></math></span>, where <em>B</em> is termed as bag constant, is presented. In order to integrate the quark core hypothesis and provide an explanation for a physically feasible stellar model, we have examined the baryon number dependent <em>B</em> (<em>n</em>) via an extreme Wood-Saxon, like parameterisation. The energy per baryon <span><math><mo>(</mo><msub><mrow><mi>E</mi></mrow><mrow><mi>B</mi></mrow></msub><mo>)</mo></math></span> has been calculated to restrict <em>B</em> (<em>n</em>) within the stable window, i.e., <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>B</mi></mrow></msub><mo>&lt;</mo><mn>930.4</mn><mspace></mspace><mi>M</mi><mi>e</mi><mi>V</mi></math></span> <span><math><mo>(</mo><mmultiscripts><mrow><mi>F</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>56</mn></mrow></mmultiscripts><mi>e</mi><mo>)</mo></math></span>. This study investigates the baryon number density (<em>n</em>) induced phase transition between hadrons and quarks inside a stellar configuration. Interestingly, the nature of the variation of <span><math><msub><mrow><mi>E</mi></mrow><mrow><mi>B</mi></mrow></msub></math></span> vs. <em>n</em>, shows that for <span><math><mi>n</mi><mo>≥</mo><mn>1.1</mn><mspace></mspace><mi>f</mi><msup><mrow><mi>m</mi></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span> the energy per baryon approaches a constant value. We choose <span><math><mi>n</mi><mo>=</mo><mn>0.6</mn><mspace></mspace><mi>f</mi><msup><mrow><mi>m</mi></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></math></span>, <span><math><mi>B</mi><mo>=</mo><mn>66.32</mn><mspace></mspace><mi>M</mi><mi>e</mi><mi>V</mi><mo>/</mo><mi>f</mi><msup><mrow><mi>m</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> within the stipulated restrictions and consider 4U 1608-52 as a strange star candidate. We find that all the characteristic properties are well satisfied within the stellar interior for the choice of parameters. The numerical solution of the TOV equations yields a maximum mass of strange quark stars of <span><math><mn>2.01</mn><mspace></mspace><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> and a corresponding radius of <span><math><mn>10.96</mn><mspace></mspace><mi>K</mi><mi>m</mi></math></span>. Proposed model meets the necessary energy conditions and also stability criteria, confirming its viability as a realistic stellar model within the parameter space used.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 231-240"},"PeriodicalIF":10.2,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102785","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":"Search for very high energy gamma-ray emission from a sample of high redshift blazars with MACE","authors":"A. Tolamatti ,&nbsp;A. Garg ,&nbsp;A. Pathania ,&nbsp;K.K. Singh ,&nbsp;C. Borwankar ,&nbsp;M. Khurana ,&nbsp;P. Chandra ,&nbsp;A. Shukla ,&nbsp;S. Godiyal ,&nbsp;S. Godambe ,&nbsp;J. Hariharan ,&nbsp;Keshavanand ,&nbsp;N. Mankuzhyil ,&nbsp;S. Norlha ,&nbsp;P. Pandey ,&nbsp;D. Sarkar ,&nbsp;R. Thubstan ,&nbsp;K. Venugopal ,&nbsp;Z.A. Dar ,&nbsp;S.V. Kotwal ,&nbsp;K.K. Yadav","doi":"10.1016/j.jheap.2024.12.006","DOIUrl":"10.1016/j.jheap.2024.12.006","url":null,"abstract":"<div><div>Blazars, a subclass of face-on jetted active galactic nuclei, are the most persistent and powerful sources of cosmic gamma-rays in the Universe. They represent a dominant population of gamma-ray sources, spread all over the sky with known and unknown redshifts up to z ∼ 6 (e.g. <span><span>Belladitta et al. (2020)</span></span>). Detection of more than 3500 blazars by the space-based <em>Fermi</em>-Large Area Telescope (LAT) in the high energy (HE, above 100 MeV) band reveals that a significant amount of power carried by the relativistic plasma jets in blazars is dissipated at gamma-ray energies. However, a small fraction of only less than 3% are detected at very high energies (VHE, above 30 GeV) by the ground-based Cherenkov telescopes. Therefore, their detection at the highest possible energies is extremely important to understand the blazar-phenomenon in the Universe. In this paper, we report observational results obtained from the recent monitoring of the six high redshift (<span><math><mi>z</mi><mspace></mspace><mo>&gt;</mo><mspace></mspace><mn>0.3</mn></math></span>) blazars with the Major Atmospheric Cherenkov Experiment (MACE) in the energy range above ∼ 80 GeV. No statistically significant detection of the sources is found. Thus, for the null detections, we estimate 99% confidence level upper limit on the integral flux for the individual sources and use the <em>Fermi</em>-LAT measurements to constrain their gamma-ray emission behavior.</div></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"45 ","pages":"Pages 241-249"},"PeriodicalIF":10.2,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143102786","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}