Journal of High Energy Astrophysics最新文献

{"title":"Exploring Universe acceleration through observational constraints via Hubble parameter reconstruction","authors":"M. Koussour ,&nbsp;N. Myrzakulov ,&nbsp;M.K.M. Ali","doi":"10.1016/j.jheap.2024.04.003","DOIUrl":"https://doi.org/10.1016/j.jheap.2024.04.003","url":null,"abstract":"<div><p>In this article, we introduce an innovative parametric representation of the Hubble parameter, providing a model-independent means to explore the dynamics of an accelerating cosmos. The model's parameters are rigorously constrained through a Markov Chain Monte Carlo (MCMC) approach, leveraging a comprehensive dataset consisting of 31 data points from cosmic chronometers (CC), 1701 updated observations of Pantheon supernovae type Ia (SNeIa), and 6 data points from baryonic acoustic oscillations (BAO). Our analysis delves into the behavior of various cosmological parameters within the model, including the transition from a decelerating phase to an accelerating one, as well as the density parameters and the equation of state (EoS) parameter. The outcomes of our investigation reveal that the equation of state parameter aligns with characteristics reminiscent of the phantom model, supporting the prevailing understanding of our universe's current state of acceleration. This research contributes valuable insights into the ongoing cosmic expansion and underscores the utility of our novel parametric approach.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 96-103"},"PeriodicalIF":3.8,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140545771","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 variability and multi-wavelength insights into the unprecedented outburst from 4C 31.03","authors":"Aminabi Thekkoth ,&nbsp;C. Baheeja ,&nbsp;S. Sahayanathan ,&nbsp;Ravikumar C.D.","doi":"10.1016/j.jheap.2024.04.005","DOIUrl":"https://doi.org/10.1016/j.jheap.2024.04.005","url":null,"abstract":"<div><p>The blazar 4C<!--> <!-->31.03 recently underwent a major <em>γ</em>-ray outburst at the beginning of 2023 after a prolonged quiescent phase. <em>Fermi</em>-LAT reported a daily average flux of <span><math><mn>5</mn><mspace></mspace><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>6</mn></mrow></msup></math></span> phs cm⁻² s⁻¹, which is about 60 times its average value. We investigated this extraordinary outbreak through temporal and multi-wavelength analysis. From the statistical analysis of the <em>γ</em>-ray lightcurves using Bayesian blocks, we identified 3 epochs of prominent flares. The fastest flux decay during this major outburst was observed within <span><math><mn>5.5</mn><mo>±</mo><mn>0.7</mn></math></span> hours. The highest energy of <em>γ</em>-ray photons found from the source during the active phase is ∼82<!--> <!-->GeV. Using the transparency of <em>γ</em>-rays against pair production and light crossing time argument, we could obtain the minimum jet Doppler factor as 17 corresponding to the flaring state. The broadband spectral energy distribution study performed using synchrotron, SSC and EC emission processes supports the external Compton scattering of IR photons as the likely mechanism for the <em>γ</em>-ray emission from the source. The results of this study support the scenario of the emission region in 4C<!--> <!-->31.03, being located beyond the Broad line region from the central blackhole. The long-term <em>γ</em>-ray flux distribution depicts a double log-normal variability, indicating that two distinct flux states are active in this energy band. The index distribution also reveals a two distinct variability pattern and hints that the <em>γ</em>-ray spectrum can be more precisely described by two photon indices.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 115-128"},"PeriodicalIF":3.8,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140632949","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":"Estimation of the atmospheric absorption profile with isotropic background events observed by Imaging Atmospheric Cherenkov Telescopes","authors":"Julian Sitarek ,&nbsp;Mario Pecimotika ,&nbsp;Natalia Żywucka ,&nbsp;Dorota Sobczyńska ,&nbsp;Abelardo Moralejo ,&nbsp;Dario Hrupec","doi":"10.1016/j.jheap.2024.03.003","DOIUrl":"https://doi.org/10.1016/j.jheap.2024.03.003","url":null,"abstract":"<div><p>Atmospheric Cherenkov telescopes rely on the Earth's atmosphere as part of the detector. The presence of clouds affects observations and can introduce biases if not corrected for. Correction methods typically require an atmospheric profile, that can be measured with external atmospheric monitoring devices. We present a novel method for measuring the atmospheric profile using the data from Imaging Atmospheric Cherenkov telescopes directly. The method exploits the comparison of average longitudinal distributions of the registered Cherenkov light between clear atmosphere and cloud presence cases. Using Monte Carlo simulations of a subarray of four Large-Sized Telescopes of the upcoming Cherenkov Telescope Array Observatory and a simple cloud model we evaluate the accuracy of the method in determining the basic cloud parameters. We find that the method can reconstruct the transmission of typical clouds with an absolute accuracy of a few per cent. For low-zenith observations, the height of the cloud centre can be reconstructed with a typical accuracy of a few hundred metres, while the geometrical thickness can be accurately reconstructed only if it is ≳3 km. We also evaluate the robustness of the method against the typical systematic uncertainties affecting atmospheric Cherenkov telescopes.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 87-95"},"PeriodicalIF":3.8,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S221440482400020X/pdfft?md5=f43746625827350c239bb86aaa6e4160&pid=1-s2.0-S221440482400020X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140543723","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":"Estimating power-law exponents from observations in electromagnetic non-minimal Maxwell-Gauss-Bonnet coupling cosmology","authors":"Rami Ahmad El-Nabulsi ,&nbsp;Waranont Anukool","doi":"10.1016/j.jheap.2024.04.002","DOIUrl":"https://doi.org/10.1016/j.jheap.2024.04.002","url":null,"abstract":"<div><p>We discuss a generalized non-minimal Maxwell-Gauss-Bonnet power-law cosmological model characterized by the presence of electromagnetic field and variable cosmological and gravitational constant. We analyze the late-time dynamics characterized by power-law solutions. The model is constrained with local gravitational acceleration measurements, the SH0ES project which estimate the Hubble parameter, Planck TT, TE, EE + low <em>E</em> +lensing +SNe+ BAO data which estimate the EoS parameter and data coming from distant supernovae type Ia, the Hubble function <span><math><mrow><mi>H</mi><mo>(</mo><mi>z</mi><mo>)</mo></mrow></math></span> measurements and information coming from the Alcock-Paczynski test which estimate the numerical range of the non-minimal coupling parameter. By adopting a variable cosmological and gravitational constants, it was found that the universe is acceleratedly expanding with time and dominated by dark/phantom energy and an electromagnetic field comparable to the cosmological lambda. The variations of the gravitational constant time agree with several phenomenological theories including the entropic and holographic principle. The final fate of an asymptotically static universe was found also to be a plausible scenario in the model discussed.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 104-114"},"PeriodicalIF":3.8,"publicationDate":"2024-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140605789","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":"Evidence for 3XMM J185246.6+003317 as a massive magnetar with a low magnetic field","authors":"Rafael C.R. de Lima ,&nbsp;Jonas P. Pereira ,&nbsp;Jaziel G. Coelho ,&nbsp;Rafael C. Nunes ,&nbsp;Paulo E. Stecchini ,&nbsp;Manuel Castro ,&nbsp;Pierre Gomes ,&nbsp;Rodrigo R. da Silva ,&nbsp;Claudia V. Rodrigues ,&nbsp;José C.N. de Araujo ,&nbsp;Michał Bejger ,&nbsp;Paweł Haensel ,&nbsp;J. Leszek Zdunik","doi":"10.1016/j.jheap.2024.04.001","DOIUrl":"https://doi.org/10.1016/j.jheap.2024.04.001","url":null,"abstract":"<div><p>3XMM J185246.6+003317 is a transient magnetar located in the vicinity of the supernova remnant Kes<!--> <!-->79. So far, observations have only set upper limits to its surface magnetic field and spindown, and there is no estimate for its mass and radius. Using ray-tracing modelling and Bayesian inference for the analysis of several light curves spanning a period of around three weeks, we have found that it may be one of the most massive neutron stars to date. In addition, our analysis suggests a multipolar magnetic field structure with a subcritical field strength and a carbon atmosphere composition. Due to the time-resolution limitation of the available light curves, we estimate the surface magnetic field and the mass to be <span><math><msub><mrow><mi>log</mi></mrow><mrow><mn>10</mn></mrow></msub><mo>⁡</mo><mo>(</mo><mi>B</mi><mo>/</mo><mi>G</mi><mo>)</mo><mo>=</mo><msubsup><mrow><mn>11.89</mn></mrow><mrow><mo>−</mo><mn>0.93</mn></mrow><mrow><mo>+</mo><mn>0.19</mn></mrow></msubsup></math></span> and <span><math><mi>M</mi><mo>=</mo><msubsup><mrow><mn>2.09</mn></mrow><mrow><mo>−</mo><mn>0.09</mn></mrow><mrow><mo>+</mo><mn>0.16</mn></mrow></msubsup></math></span> <span><math><msub><mrow><mi>M</mi></mrow><mrow><mo>⊙</mo></mrow></msub></math></span> at 1<em>σ</em> confidence level, while the radius is estimated to be <span><math><mi>R</mi><mo>=</mo><msubsup><mrow><mn>12.02</mn></mrow><mrow><mo>−</mo><mn>1.42</mn></mrow><mrow><mo>+</mo><mn>1.44</mn></mrow></msubsup></math></span> km at 2<em>σ</em> confidence level. They were verified by simulations, i.e., data injections with known model parameters, and their subsequent recovery. The best-fitting model has three small hot spots, two of them in the southern hemisphere. These are, however, just first estimates and conclusions, based on a simple ray-tracing model with anisotropic emission; we also estimate the impact of modelling on the parameter uncertainties and the relevant phenomena on which to focus in more precise analyses. We interpret the above best-fitting results as due to accretion of supernova layers/interstellar medium onto 3XMM J185246.6+003317 leading to burying and a subsequent re-emergence of the magnetic field, and a carbon atmosphere being formed possibly due to hydrogen/helium diffusive nuclear burning. Finally, we briefly discuss some consequences of our findings for superdense matter constraints.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 52-62"},"PeriodicalIF":3.8,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140536779","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":"Rényi topology of charged-flat black hole: Hawking-Page and Van-der-Waals phase transitions","authors":"F. Barzi ,&nbsp;H. El Moumni ,&nbsp;K. Masmar","doi":"10.1016/j.jheap.2024.03.005","DOIUrl":"https://doi.org/10.1016/j.jheap.2024.03.005","url":null,"abstract":"<div><p>In this paper, we extend the proposed setup in <span>Wei et al. (2022)</span>; <span>Yerra et al. (2022)</span> for finding the topological charges associated with the Hawking-Page and Van-der-Waals transition points as well as equilibrium phases to catch the nonextensive nature of the black hole entropy. Rigorously speaking we incorporate the Rényi statistics formalism in off-shell Bragg-Williams free energy landscape, to examine topologically the Hawking-Page phase transition related to the uncharged/charged asymptotically flat black hole in grand canonical and the Van-der-Waals transition in the canonical ensemble, where a vortex/anti-vortex structure is found. For this purpose, we introduce three mappings, the <em>ψ</em>- and <em>ξ</em>-mapping, for phase transitions classification and the <em>η</em>-mapping for equilibrium phases classification. We found that Hawking-Page and Van-der-Waals phase transitions belong to different topological classes and exhibit an interplay of total charge values hinting to a possible new correspondence.</p><p>Our topological study provides further substantiation for a possible conjecture positing a correspondence between the thermodynamic characteristics of black holes in asymptotically flat spacetime using Rényi statistics, and those in asymptotically Anti-de-Sitter spacetime employing Gibbs-Boltzmann statistics.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 63-86"},"PeriodicalIF":3.8,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140536780","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":"LISA and LISA-like mission test-mass charging for gamma-ray burst detection","authors":"Catia Grimani ,&nbsp;Mattia Villani ,&nbsp;Michele Fabi ,&nbsp;Federico Sabbatini","doi":"10.1016/j.jheap.2024.03.004","DOIUrl":"https://doi.org/10.1016/j.jheap.2024.03.004","url":null,"abstract":"<div><p>Cubic gold-platinum test-masses (TMs) play the role of free-falling geodesic reference and interferometer end mirrors of the future Laser Interferometer Space Antenna (LISA) observatory for low-frequency gravitational wave detection in space. A similar arrangement has been proposed for the Chinese missions Taiji and TianQin and for the LISA follow-on missions such as ALIA and BBO. The TMs are charged by high-energy particles and photons. The deposited charge couples with stray electric fields surrounding the TMs thus inducing spurious forces that limit the sensitivity of the mission mainly at low frequencies. The TM charging was measured in space in 2016-2017 with LISA Pathfinder (LPF), meant for the testing of the LISA instrumentation. Unfortunately, during the time LPF remained in orbit, no solar energetic particle events or major astrophysical phenomena were observed. We aim at estimating the LISA TM charging attributable to long, short gamma-ray bursts (GRBs) and magnetar flares in comparison to that of charged particles of galactic and solar origin. The contribution of these major astrophysical phenomena to the LISA TM charging is discussed here for the first time. The results found here can be extended to LISA-like missions. The response of the radiation monitors hosted on the three LISA S/C is also evaluated. We show that long, intense extragalactic GRBs and galactic magnetar flares at kpc distances can be detected and monitored through a sudden change from positive to negative charging of the TMs and an increase of the TM charging noise. This is a unique signature since both galactic and solar particles charge positively the LISA TMs. This peculiar behavior of the TM charging would allow monitoring the whole dynamics of GRBs. The suggestion reported in the literature, about the detection of long GRBs and gravitational waves from the same sources, in principle, may apply to LISA and other LISA-like missions since the increase of the TM charging noise during these extreme transient phenomena is estimated to remain below the mission sensitivity while particle detectors are expected to saturate.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 38-51"},"PeriodicalIF":3.8,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2214404824000211/pdfft?md5=8bed941077f774c30dabc23dc1b831b3&pid=1-s2.0-S2214404824000211-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140536782","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":"Periodicity of sub-pulses in a radio pulsar","authors":"Peng-Fu Tian ,&nbsp;Ping Zhang ,&nbsp;Wen Yang ,&nbsp;Wei Wang ,&nbsp;Pei Wang","doi":"10.1016/j.jheap.2024.03.002","DOIUrl":"10.1016/j.jheap.2024.03.002","url":null,"abstract":"<div><p>Pulsars are known to manifest complex phenomena, such as nulling, sub-pulse drifting, and periodicity. Within the purview of this investigation, we have harnessed the wavelet analysis technique to scrutinize the multifaceted periodicities and sub-pulse drifting characteristics exhibited by PSR J1926-0652, discovered by the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Our analysis draws upon the rich dataset acquired from the FAST ultra-wide-bandwidth receiver (UWB), meticulously examining pulse attributes encompassing an entire pulse. It is notable that the pulse apex recurrently manifests approximately every 17.11 times the pulsar's period P, individual sub-pulses exhibit a drifting phenomenon, with a phase decrement of approximately <span><math><msup><mrow><mn>1.04</mn></mrow><mrow><mo>∘</mo></mrow></msup></math></span> over each P. Intriguingly, the central phase of each sub-pulse track gradually increments over temporal evolution. Furthermore, the relative offset distribution between successive sub-pulse tracks emanating from the trailing and leading components remains comparatively stable, with a central tendency of approximately ∼6.87±2.56 P. Most notably, derived from the outcomes of wavelet analysis, we ascertain a negative correlation of -0.98 between the periods of sub-pulses and their drifting rates, alongside the intrinsic period of sub-pulses identified at 28.14 seconds.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 27-37"},"PeriodicalIF":3.8,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202783","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":"The properties of FR0 radio galaxies as intermediate objects in the evolution of radio galaxies","authors":"David Garofalo ,&nbsp;Chandra B. Singh ,&nbsp;Eddie Harmon ,&nbsp;Michael Williams ,&nbsp;Luis Rojas Castillo","doi":"10.1016/j.jheap.2024.03.001","DOIUrl":"10.1016/j.jheap.2024.03.001","url":null,"abstract":"<div><p>It is becoming increasingly clear that counter-rotation between black holes and accretion disks is key to understanding radio galaxies. Such an accretion configuration was introduced over a decade ago to elucidate the nature of the radio loud/radio quiet dichotomy and the jet-disk connection, but has since been applied to a plethora of observations across space and time, from isolated to rich environments and from the formation of the first quasars to the nature of mature objects like M87. We briefly review the paradigm in which counter-rotation is key for the triggering of radio galaxies and its observational support, to then apply it to a series of seemingly unrelated observations concerning FR0 radio galaxies which we argue trace their explanation to one overarching theoretical idea. FR0 radio galaxies appear to be radio galaxies in transition, with low spinning black holes and thus weaker but tilted jets with respect to an earlier radio quasar phase. As a result of this jet reorientation, FR0 radio galaxies are prescribed to be in an earlier phase of star formation suppression in radio galaxies, compared to a later phase that is unlikely to be less than tens of millions of years in their future if they have enough accretion fuel to evolve into more powerful FRI radio galaxies. FR0 radio galaxies will have a greater or lesser star formation suppression feedback effect depending on how long they live. Tilted jets also enhance stellar velocities in the bulge. Because FR0 jet lengths are of the same order of magnitude as the radius of the stellar bulge, FR0 jets are prescribed to have begun, more or less recently depending on their age, to affect stellar velocity dispersions as well. As a result, they will be associated with dispersion values that tend to be larger than for characteristically non-jetted active galaxies, but smaller than for giant radio galaxies such as M87 that have experienced a long-term tilted and more powerful FRI jet. With these ideas it is possible to make a coarse-grained prediction for the slope on the M-σ plane for FR0 radio galaxies with values between 4 and 8.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"42 ","pages":"Pages 21-26"},"PeriodicalIF":3.8,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140202782","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":"Type-I X-ray burst evolution of the new millisecond pulsar MAXI J1816–195 revealed by Insight-HXMT","authors":"P.J. Wang ,&nbsp;Y.P. Chen ,&nbsp;L. Ji ,&nbsp;S. Zhang ,&nbsp;S.N. Zhang ,&nbsp;L.D. Kong ,&nbsp;L. Zhang ,&nbsp;L. Tao ,&nbsp;J.L. Qu ,&nbsp;M.Y. Ge ,&nbsp;J. Li ,&nbsp;Z. Chang ,&nbsp;J.Q. Peng ,&nbsp;Q.C. Shui ,&nbsp;Z.S. Li","doi":"10.1016/j.jheap.2024.02.004","DOIUrl":"10.1016/j.jheap.2024.02.004","url":null,"abstract":"<div><p>We report a study of the type-I X-ray bursts and persistent spectrum of the 2022 outburst of the newly discovered accreting millisecond pulsar MAXI J1816–195 observed by <em>Insight-HXMT</em>. The spectra of MAXI J1816–195 are similar to other accreting millisecond pulsars, i.e., a Comptonization shape with an electron temperature of ∼10 keV. We find that the profiles of type-I X-ray bursts, as well as their spectra, evolve during the outburst. The evolutionary pattern becomes varied towards the end phase of outburst, suggesting a potential correlation with alterations in the burst fuel or the ignition region. Moreover, we find a giant burst, for the first time, with a peak luminosity twice than others and a shorter burst duration. The complete burst sample derived from this research provides more clues in probing the thermonuclear bursts during the outburst of the accreting millisecond pulsar system.</p></div>","PeriodicalId":54265,"journal":{"name":"Journal of High Energy Astrophysics","volume":"41 ","pages":"Pages 106-113"},"PeriodicalIF":3.8,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140016655","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}