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Journal articles on the topic 'Gamma-rays: burst'

Author: Grafiati

Published: 9 March 2023

Last updated: 19 July 2025

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Fishman, Gerald J. "Gamma-Ray Burst Observations with BATSE." Symposium - International Astronomical Union 188 (1998): 159–62. http://dx.doi.org/10.1017/s0074180900114664.

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Gamma-ray bursts (GRBs) will be recorded as one of the outstanding new phenomena discovered in astronomy this century. About once per day, a burst of gamma rays appears from a random direction on the sky. Often, the burst outshines all other sources of gamma-rays in the sky, combined. This paper reviews some of the key observed phenomenon of bursts in the hard x-ray/gamma-ray region, as observed with the BATSE experiment on the Compton Gamma Ray Observatory. The observed time profiles, spectral properties and durations of gamma-ray bursts cover a wide range. Recent breakthroughs in the observation of gamma-ray burst counterparts and afterglows in other wavelength regions have marked the beginning of a new era in gamma-ray burst research. Those observations are described in following papers in these proceedings.

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Chadwick, Paula M. "Very high-energy gamma rays from gamma-ray bursts." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 365, no. 1854 (2007): 1343–56. http://dx.doi.org/10.1098/rsta.2006.1971.

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Very high-energy (VHE) gamma-ray astronomy has undergone a transformation in the last few years, with telescopes of unprecedented sensitivity having greatly expanded the source catalogue. Such progress makes the detection of a gamma-ray burst at the highest energies much more likely than previously. This paper describes the facilities currently operating and their chances for detecting gamma-ray bursts, and reviews predictions for VHE gamma-ray emission from gamma-ray bursts. Results to date are summarized.

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Epstein, Richard I. "Physical Constraints on Models of Gamma-Ray Bursters." International Astronomical Union Colloquium 89 (1986): 305–21. http://dx.doi.org/10.1017/s0252921100086140.

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AbstractThe power per logarithmic bandwidth in gamma-ray burst spectra generally increases rapidly with energy through the x-ray range and does not cut off sharply above a few MeV. This spectral form indicates that a very small fraction of the energy from a gamma-ray burst source is emitted at low energies or is reprocessed into x-rays and that the high-energy gamma rays are not destroyed by photon-photon interactions. The implications are that the emission mechanism for the gamma-ray bursts is not synchrotron radiation from electrons that lose most of their energy before being re-accelerated and that either the regions from which the gamma rays are emitted are large compared to the size of a neutron star or the emission is collimated and beamed away from the stellar surface.

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Aharonian, F., F. Ait Benkhali, J. Aschersleben, et al. "Search for the evaporation of primordial black holes with H.E.S.S." Journal of Cosmology and Astroparticle Physics 2023, no. 04 (2023): 040. http://dx.doi.org/10.1088/1475-7516/2023/04/040.

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Abstract Primordial Black Holes (PBHs) are hypothetical black holes predicted to have been formed from density fluctuations in the early Universe. PBHs with an initial mass around 1014–1015 g are expected to end their evaporation at present times in a burst of particles and very-high-energy (VHE) gamma rays. Those gamma rays may be detectable by the High Energy Stereoscopic System (H.E.S.S.), an array of imaging atmospheric Cherenkov telescopes. This paper reports on the search for evaporation bursts of VHE gamma rays with H.E.S.S., ranging from 10 to 120 seconds, as expected from the final stage of PBH evaporation and using a total of 4816 hours of observations. The most constraining upper limit on the burst rate of local PBHs is 2000 pc-3 yr-1 for a burst interval of 120 seconds, at the 95% confidence level. The implication of these measurements for PBH dark matter are also discussed.

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BARSHAY, SAUL, and GEORG KREYERHOFF. "VERY HIGH-ENERGY NEUTRINOS FROM SLOWLY DECAYING, MASSIVE DARK MATTER AS A SOURCE OF EXPLOSIVE ENERGY FOR GAMMA-RAY BURSTS." Modern Physics Letters A 18, no. 07 (2003): 477–89. http://dx.doi.org/10.1142/s0217732303009654.

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We consider a speculative model for gamma-ray bursts (GRB), which predicts that the total kinetic energy in the ejected matter is less than the total energy in the gamma rays. There is also secondary energy in X-rays, which are emitted contemporaneously with the gamma rays. The model suggests that bremsstrahlung and Compton up-scattering by very energetic electrons, are important processes for producing the observed burst radiation. The dynamics naturally allows for the possibility of a moderate degree of beaming of matter and radiation in some gamma-ray bursts. GRB are predicted to have an intrinsically wide distribution in total energies, in particular, on the low side. They are predicted to occur at large redshifts, z ~ 8, in local regions of dense matter.

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Harding, Alice K. "Gamma-Ray Burst Theory: Back to the Drawing Board." International Astronomical Union Colloquium 142 (1994): 863–68. http://dx.doi.org/10.1017/s0252921100078222.

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AbstractGamma-ray bursts have always been intriguing sources to study in terms of particle acceleration, but not since their discovery two decades ago has the theory of these objects been in such turmoil. Prior to the launch of Compton Gamma-Ray Observatory and observations by BATSE, there was strong evidence pointing to magnetized Galactic neutron stars as the sources of gamma-ray bursts. However, since BATSE the observational picture has changed dramatically, requiring much more distant and possibly cosmological sources. I review the history of gamma-ray burst theory from the era of growing consensus for nearby neutron stars to the recent explosion of halo and cosmological models and the impact of the present confusion on the particle acceleration problem.Subject headings: acceleration of particles — gamma rays: bursts

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Coelho, Jaziel G., Luana N. Padilha, Rita C. dos Anjos, Cynthia V. Ventura, and Geanderson A. Carvalho. "An updated view and perspectives on high-energy gamma-ray emission from SGR J1935+2154 and its environment." Journal of Cosmology and Astroparticle Physics 2022, no. 10 (2022): 041. http://dx.doi.org/10.1088/1475-7516/2022/10/041.

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Abstract SGR J1935+2154 was discovered in 2016 and is currently one of the most burst-active Soft Gamma-ray Repeaters (SGR), having emitted many X-ray bursts in recent years. In one of our previous articles, we investigated the contribution to high-energy and very high-energy gamma-ray emission (VHE, E > 100 GeV) due to cosmic-ray acceleration of SNR G57.2+0.8 hosting SGR J1935+2154 using the GALPROP propagation code. However, follow-up observations of SGR 1935+2154 were made for 2 hours on April 28, 2020, using the High Energy Stereoscopic System (H.E.S.S.). The observations coincide with X-ray bursts detected by INTEGRAL and Fermi/Gamma-ray Burst Monitor (GBM). These are the first high-energy gamma-ray observations of an SGR in a flaring state, and upper limits on sustained and transient emission have been derived. Now that new H.E.S.S. observations have been made, it is interesting to update our model with respect to these new upper limits. We extend our previous results to a more general situation using the new version of GALPROP. We obtain a hadronic model that confirms the results discussed by H.E.S.S. . This leads to an optimistic prospect that cosmic ray gamma rays from SGR J1935+2154 can contribute to the overall gamma energy density distribution and in particular to the diffusion gamma rays from the Galactic center.

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Huang, Jihong, Yilin Wang, Bingrong Yu, and Shun Zhou. "Invisible neutrino decays as origin of TeV gamma rays from GRB221009A." Journal of Cosmology and Astroparticle Physics 2023, no. 04 (2023): 056. http://dx.doi.org/10.1088/1475-7516/2023/04/056.

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Abstract Recently, the LHAASO collaboration has observed the gamma rays of energies up to ten TeV from the gamma-ray burst GRB221009A, which has stimulated the community of astronomy, particle physics and astrophysics to propose various possible interpretations. In this paper, we put forward a viable scenario that neutrinos are produced together with TeV photons in the gamma-ray burst and gradually decay into the axion-like particles, which are then converted into gamma rays in the galactic magnetic fields. In such a scenario, the tension between previous axion-like particle interpretations and the existing observational constraints on the relevant coupling constant and mass can be relaxed.

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Hurley, Kevin. "Observational Features of Cosmic Gamma-Ray Bursts: Evidence for Galactic Versus Extragalactic Origin." International Astronomical Union Colloquium 142 (1994): 857–61. http://dx.doi.org/10.1017/s0252921100078210.

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AbstractThe recent observational data on gamma-ray bursts are reviewed. Burst time histories display features at the millisecond level which suggest a compact object origin. Lines in the energy spectra and spectral evolution point toward a Galactic neutron star origin, even though line features have not yet been confirmed in recent data. The Galactic distribution of burst sources, however, is both isotropic and sampled to its characteristic distance, making it unlikely that the sources are related to populations of Galactic neutrons stars we are familiar with. Counterpart searches, previously carried out years after the gamma-ray bursts, are now proceeding days after the events. Based on the current data, it is impossible to conclude whether bursters are Galactic, extragalactic, or both. Data being returned from current experiments, as well as data from new experiments to be launched in the next few years, may yet provide the answer.Subject heading: gamma rays: bursts

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Vestrand, W. T., J. A. Wren, A. Panaitescu, et al. "The Bright Optical Flash and Afterglow from the Gamma-Ray Burst GRB 130427A." Science 343, no. 6166 (2013): 38–41. http://dx.doi.org/10.1126/science.1242316.

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The optical light generated simultaneously with x-rays and gamma rays during a gamma-ray burst (GRB) provides clues about the nature of the explosions that occur as massive stars collapse. We report on the bright optical flash and fading afterglow from powerful burst GRB 130427A. The optical and >100–megaelectron volt (MeV) gamma-ray flux show a close correlation during the first 7000 seconds, which is best explained by reverse shock emission cogenerated in the relativistic burst ejecta as it collides with surrounding material. At later times, optical observations show the emergence of emission generated by a forward shock traversing the circumburst environment. The link between optical afterglow and >100-MeV emission suggests that nearby early peaked afterglows will be the best candidates for studying gamma-ray emission at energies ranging from gigaelectron volts to teraelectron volts.

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van Eerten, Hendrik. "Gamma-ray burst afterglow blast waves." International Journal of Modern Physics D 27, no. 13 (2018): 1842002. http://dx.doi.org/10.1142/s0218271818420026.

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The various stages of baryonic gamma-ray burst (GRB) afterglow blast waves are reviewed. These are responsible for the afterglow emission from which much of our understanding of gamma-ray bursts derives. Initially, the blast waves are confined to the dense medium surrounding the burster (stellar envelope or dense wind), giving rise to a jet-cocoon structure. A massive ejecta is released and potentially fed by ongoing energy release from the burster and a forward–reverse shock system is set up between ejecta and ambient density. Ultimately the blast wave spreads sideways and slows down, and the dominant afterglow emission shifts from X-rays down to radio. Over the past years significant progress has been made both observationally and theoretically/numerically in our understanding of these blast waves, unique in the universe due to their often incredibly high initial Lorentz factors of 100–1000. The recent discovery of a short gamma-ray burst counterpart to a gravitational wave detection (GW 170817) brings the promise of a completely new avenue to explore and constrain the dynamics of gamma-ray burst blast waves.

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MÉSZÁROS, PETER. "GAMMA-RAY BURSTS AS VHE-UHE SOURCES." International Journal of Modern Physics D 17, no. 09 (2008): 1319–32. http://dx.doi.org/10.1142/s0218271808012875.

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Gamma-ray bursts are capable of accelerating cosmic rays up to GZK energies Ep ~ 1020 eV, which can lead to a flux at Earth comparable to that observed by large EAS arrays such as Auger. The semi-relativistic outflows inferred in GRB-related hypernovae are also likely sources of somewhat lower energy cosmic rays. Leptonic processes, such as synchrotron and inverse Compton, as well as hadronic processes, can lead to GeV-TeV gamma-rays measurable by GLAST, AGILE, or ACTs, providing useful probes of the burst physics and model parameters. Photo-meson interactions also produce neutrinos at energies ranging from sub-TeV to EeV, which will be probed with forthcoming experiments such as IceCube, ANITA and KM3NeT. This would provide information about the fundamental interaction physics, the acceleration mechanism, the nature of the sources and their environment.

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MARTÍN, OSMEL, ROLANDO CÁRDENAS, JORGE E. HORVATH, and LIUBA PEÑATE. "EFFECTS OF GALACTIC GAMMA RAYS BURSTS ON PLANETARY ATMOSPHERES." International Journal of Modern Physics E 20, supp02 (2011): 67–70. http://dx.doi.org/10.1142/s021830131104061x.

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We discuss the potential past incidence of a galactic gamma ray burst on Earth. Rough estimates for the relative frequencies of this kind of event are given, for the different eons of our planet's geological history. Additionally, we explore the effectiveness of the ozone layer of different paleo-atmospheres to shield the surface of the planet from the ultraviolet flash, which arises as a short-term effect after the incidence of a galactic gamma ray burst.

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KAPPES, ALEXANDER. "GAMMA-RAY BURST DETECTION WITH ICECUBE." International Journal of Modern Physics D 18, no. 10 (2009): 1561–65. http://dx.doi.org/10.1142/s0218271809015473.

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With their narrow emission window gamma-ray bursts (GRBs) are among the most promising objects for the first identification of high-energy cosmic neutrinos. If a considerable fraction of the ultra-high energy cosmic rays is indeed produced in GRBs, IceCube, which is now more than half-way completed, should be able to detect the associated neutrinos in the next few years. Furthermore, optical follow-up observations of neutrino multiplets will enhance IceCube's sensitivity to choked GRBs which do not produce a gamma-ray signal.

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Adriani, O., Y. Akaike, K. Asano, et al. "CALET Search for Electromagnetic Counterparts of Gravitational Waves during the LIGO/Virgo O3 Run." Astrophysical Journal 933, no. 1 (2022): 85. http://dx.doi.org/10.3847/1538-4357/ac6f53.

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Abstract The CALorimetric Electron Telescope (CALET) on the International Space Station consists of a high-energy cosmic-ray CALorimeter (CAL) and a lower-energy CALET Gamma-ray Burst Monitor (CGBM). CAL is sensitive to electrons up to 20 TeV, cosmic-ray nuclei from Z = 1 through Z ∼ 40, and gamma rays over the range 1 GeV–10 TeV. CGBM observes gamma rays from 7 keV to 20 MeV. The combined CAL-CGBM instrument has conducted a search for gamma-ray bursts (GRBs) since 2015 October. We report here on the results of a search for X-ray/gamma-ray counterparts to gravitational-wave events reported during the LIGO/Virgo observing run O3. No events have been detected that pass all acceptance criteria. We describe the components, performance, and triggering algorithms of the CGBM—the two Hard X-ray Monitors consisting of LaBr3(Ce) scintillators sensitive to 7 keV–1 MeV gamma rays and a Soft Gamma-ray Monitor BGO scintillator sensitive to 40 keV–20 MeV—and the high-energy CAL consisting of a charge detection module, imaging calorimeter, and the fully active total absorption calorimeter. The analysis procedure is described and upper limits to the time-averaged fluxes are presented.

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Jordana-Mitjans, N., C. G. Mundell, C. Guidorzi, et al. "A Short Gamma-Ray Burst from a Protomagnetar Remnant." Astrophysical Journal 939, no. 2 (2022): 106. http://dx.doi.org/10.3847/1538-4357/ac972b.

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Abstract The contemporaneous detection of gravitational waves and gamma rays from GW170817/GRB 170817A, followed by kilonova emission a day after, confirmed compact binary neutron star mergers as progenitors of short-duration gamma-ray bursts (GRBs) and cosmic sources of heavy r-process nuclei. However, the nature (and life span) of the merger remnant and the energy reservoir powering these bright gamma-ray flashes remains debated, while the first minutes after the merger are unexplored at optical wavelengths. Here, we report the earliest discovery of bright thermal optical emission associated with short GRB 180618A with extended gamma-ray emission—with ultraviolet and optical multicolor observations starting as soon as 1.4 minutes post-burst. The spectrum is consistent with a fast-fading afterglow and emerging thermal optical emission 15 minutes post-burst, which fades abruptly and chromatically (flux density F ν ∝ t −α , α = 4.6 ± 0.3) just 35 minutes after the GRB. Our observations from gamma rays to optical wavelengths are consistent with a hot nebula expanding at relativistic speeds, powered by the plasma winds from a newborn, rapidly spinning and highly magnetized neutron star (i.e., a millisecond magnetar), whose rotational energy is released at a rate L th ∝ t −(2.22±0.14) to reheat the unbound merger-remnant material. These results suggest that such neutron stars can survive the collapse to a black hole on timescales much larger than a few hundred milliseconds after the merger and power the GRB itself through accretion. Bright thermal optical counterparts to binary merger gravitational wave sources may be common in future wide-field fast-cadence sky surveys.

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Dainotti, M. G., S. Bhardwaj, E. Bissaldi, N. Fraija, S. Sourav, and A. Galvan-Gamez. "Analysis of Gamma-Ray Burst Closure Relationship in Multiple Wavelengths." Astrophysical Journal 978, no. 1 (2024): 51. https://doi.org/10.3847/1538-4357/ad93b5.

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Abstract Gamma-ray bursts (GRBs) are intense pulses of high-energy emission associated with the death of massive stars or compact objects’ coalescence. Their multiwavelength observations help verify the reliability of the standard fireball model. We analyze 14 GRBs observed contemporaneously in gamma rays by the Fermi Large Area Telescope, in X-rays by the Swift Telescope, and in the optical bands by Swift and many ground-based telescopes. We study the correlation between the spectral and temporal indices using closure relations according to the synchrotron forward-shock model in a stratified medium (n ∝ r −k ) with k ranging from 0 to 2.5. We find that the model without energy injection is preferred over the one with energy injection in all the investigated wavelengths. In gamma rays, we only explored the ν > max{ν c , ν m } (slow cooling, SC/fast cooling, FC) cooling condition (where ν c and ν m are the cooling and characteristic frequencies, namely the frequencies at the spectral break). In the X-ray and optical bands, we explored all the cooling conditions, including ν m < ν < ν c (SC), ν c < ν < ν m (FC), and SC/FC, and found a clear preference for SC for X-rays and SC/FC for optical. Within these cooling conditions, X-rays exhibit the highest rate of occurrence for the density profile with k = 0, while the optical band has the highest occurrence for k = 2.5 when considering no energy injection. Although we can pinpoint a definite environment for some GRBs, we find degeneracies in other GRBs.

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Sato, Yuri, Kaori Obayashi, Ryo Yamazaki, Kohta Murase, and Yutaka Ohira. "Off-axis jet scenario for early afterglow emission of low-luminosity gamma-ray burst GRB 190829A." Monthly Notices of the Royal Astronomical Society 504, no. 4 (2021): 5647–55. http://dx.doi.org/10.1093/mnras/stab1273.

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ABSTRACT Recently, ground-based Imaging Atmospheric Cherenkov Telescopes have reported the detection of very-high-energy (VHE) gamma-rays from some gamma-ray bursts (GRBs). One of them, GRB 190829A, was triggered by the Swift satellite, and about 2 × 104 s after the burst onset the VHE gamma-ray emission was detected by H.E.S.S. with ∼5σ significance. This event had unusual features of having much smaller isotropic equivalent gamma-ray energy than typical long GRBs and achromatic peaks in X-ray and optical afterglow at about 1.4 × 103 s. Here, we propose an off-axis jet scenario that explains these observational results. In this model, the relativistic beaming effect is responsible for the apparently small isotropic gamma-ray energy and spectral peak energy. Using a jetted afterglow model, we find that the narrow jet, which has the initial Lorentz factor of 350 and the initial jet opening half-angle of 0.015 rad, viewed off-axis can describe the observed achromatic behaviour in the X-ray and optical afterglow. Another wide, baryon-loaded jet is necessary for the later-epoch X-ray and radio emissions. According to our model, the VHE gamma rays observed by H.E.S.S. at 2 × 104 s may come from the narrow jet through the synchrotron self-Compton process.

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Merck, M., D. L. Bertsch, B. L. Dingus, et al. "Observations of High-energy Gamma-ray Bursts with EGRET." International Astronomical Union Colloquium 151 (1995): 358–62. http://dx.doi.org/10.1017/s0252921100035351.

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Gamma Ray Bursts (GRBs) have puzzled astronomers since their discovery more than 20 years ago. As no counterparts at wavelengths other than X- and γ-rays have yet been found the identification of the sources is still missing. Theoretical explanations range from colliding comets (1993) and merging neutron stars (1982) to more exotic objects, such as superconducting cosmic strings (1988). Data accumulated until now still do not discriminate between these models, although results from the BATSE (Burst and Transient Source Experiment) instrument aboard the Compton Gamma Ray Observatory (CGRO) strongly favor extragalactic models.The Energetic Gamma Ray Experiment Telescope (EGRET) aboard CGRO has s ofar detected photons from 5 GRBs with its spark chamber. These are the highest energy γ-rays associated with GRBs to date. In this work we review previously published data and summarize the properties of these events. Elsewhere we present possible constraints from the data on the models proposed to explain GRBs.

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Hartmann, Dieter H., Lawrence E. Brown, Lih-Sin The, et al. "Do Gamma-Ray Bursts Originate from an Extended Galactic Halo of High-Velocity Neutron Stars?" International Astronomical Union Colloquium 142 (1994): 893–97. http://dx.doi.org/10.1017/s0252921100078271.

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AbstractThe γ-ray burst brightness distribution is inhomogeneous and the distribution on the sky is nearly isotropic. These features argue against an association of γ-ray bursts with those Galactic objects that are known to exhibit a strong concentration toward the Galactic center or plane. The observed statistical properties indicate a cosmological origin. Circumstantial evidence suggests that neutron stars are involved in the burst phenomenon. Here we consider Population II neutron stars in an extended Galactic Halo (EGH) as an alternative to cosmological scenarios. The BATSE data indicate a small deviation from isotropy near the 2 σ level of statistical significance. If confirmed for an increasing number of bursts, these anisotropies could rule out cosmological scenarios. On the other hand, EGH models require small anisotropies like those observed by BATSE. We consider simple distribution models to determine the generic properties such halos must have to be consistent with the observations and discuss the implications of the corresponding distance scale on burst models.Subject headings: gamma rays: bursts — stars: neutron — stars: Population II — stars: statistics

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Li, Dong, Hu Jiang, Xiaofeng Zhang, Ruifeng Su, and Junwang He. "Space approaching assessment of SVOM satellite to other space objects." Journal of Physics: Conference Series 2879, no. 1 (2024): 012046. http://dx.doi.org/10.1088/1742-6596/2879/1/012046.

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Abstract The SVOM satellite is one of the joint space projects between China and France. It was successfully launched into the preferred orbit in June 2024. Its goal is to monitor the Gamma Ray Burst in space. The mission consists of 4 main instruments: ECLAIRs, MXT, GRM, and VT. The ECLAIRs telescope is used to detect and position gamma bursts in the X-ray band and low-energy gamma rays. Micro-channel X-ray Telescope (MXT telescope) will make the observation of gamma bursts in the soft X-ray range. GRM (Gamma Ray Burst Monitor) is used to measure the spectrum of high-energy bursts. VT telescope (Visible Telescope) operates in the visible range to detect and observe the visible emission produced immediately after a gamma burst. Based on recent orbit elements for the SVOM satellite, which was available via TT&C, SOCRATES Plus software is used to carry out space collision assessment for the SVOM satellite. SVOM and the accompanying satellite shared the same rocket before they were sent into their own preferred orbits. During the simulations, the mean main orbit elements are derived from the GNSS PV data sets, which can help to know the orbit health of SVOM. On June 27, 2024, the distance between SVOM and the accompanying satellite varies between 509 km and 620 km, and the distance between SVOM and the rocket residual varies between 441 km and 5263 km. On July 2, 2024, the distance between SVOM and the accompanying satellite varies between 1067 km and 1180 km, and the distance between SVOM and the rocket residual varies between 357 Km and 5107 Km. In addition, space approaching the SVOM satellite and other objects is simulated for five-day intervals; it turns out that there are three space objects approaching the SVOM satellite with about 4 km - 5 Km separation.

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Zhang, B. Theodore, Kohta Murase, Kunihito Ioka, Deheng Song, Chengchao Yuan, and Péter Mészáros. "External Inverse-compton and Proton Synchrotron Emission from the Reverse Shock as the Origin of VHE Gamma Rays from the Hyper-bright GRB 221009A." Astrophysical Journal Letters 947, no. 1 (2023): L14. http://dx.doi.org/10.3847/2041-8213/acc79f.

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Abstract The detection of the hyper-bright gamma-ray burst (GRB) 221009A enables us to explore the nature of the GRB emission and the origin of very high-energy gamma rays. We analyze the Fermi Large Area Telescope (Fermi-LAT) data of this burst and investigate the GeV–TeV emission in the framework of the external reverse-shock model. We show that the early ∼1–10 GeV emission can be explained by the external inverse-Compton mechanism via upscattering MeV gamma rays by electrons accelerated at the reverse shock, in addition to the synchrotron self-Compton component. The predicted early optical flux could have been brighter than that of the naked-eye GRB 080319B. We also show that proton synchrotron emission from accelerated ultrahigh-energy cosmic rays (UHECRs) is detectable and could potentially explain ≳TeV photons detected by LHAASO or constrain the UHECR acceleration mechanism. Our model suggests that the detection of  ( 10 TeV ) photons with energies up to ∼18 TeV is possible for reasonable models of the extragalactic background light without invoking new physics and predicts anticorrelations between MeV photons and TeV photons, which can be tested with the LHAASO data.

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Fletcher, C., J. Wood, R. Hamburg, et al. "A Joint Fermi-GBM and Swift-BAT Analysis of Gravitational-wave Candidates from the Third Gravitational-wave Observing Run." Astrophysical Journal 964, no. 2 (2024): 149. http://dx.doi.org/10.3847/1538-4357/ad1eed.

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Abstract We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift-BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers.

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Kryvdyk, Volodymyr. "Particle dynamics in the stellar magnetosphere by gravitational collapse." Proceedings of the International Astronomical Union 6, S271 (2010): 383–84. http://dx.doi.org/10.1017/s174392131101790x.

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AbstractThe particle dynamics and in the stellar magnetosphere during gravitational collapse is investigated. The formations of relativistic jets and the generation of the radiation bursts in the stellar magnetosphere by gravitational collapse are considered. As follows from results, the stars on the stage of gravitational collapse must be powerful sources of the relativistic jets and the non-thermal radiation. These jets will formed in the polar caps of collapsing stars magnetospheres, when the stellar magnetic field increases during collapse and the charged particles will be accelerate. These jets will generate the non-thermal radiation. The radiation flux grows with decreasing stellar radius and can be observed in the form of radiation burst in wide band wave- from radio to gamma-ray. These bursts radiation can be observed as gamma- and X- rays bursts.

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Ahlers, Markus, and Lea Halser. "Neutrino fluence from gamma-ray bursts: off-axis view of structured jets." Monthly Notices of the Royal Astronomical Society 490, no. 4 (2019): 4935–43. http://dx.doi.org/10.1093/mnras/stz2980.

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ABSTRACT We investigate the expected high-energy neutrino fluence from internal shocks produced in the relativistic outflow of gamma-ray bursts. Previous model predictions have primarily focused on on-axis observations of uniform jets. Here, we present a generalization to account for arbitrary viewing angles and jet structures. Based on this formalism, we provide an improved scaling relation that expresses off-axis neutrino fluences in terms of on-axis model predictions. We also find that the neutrino fluence from structured jets can exhibit a strong angular dependence relative to that of gamma-rays and can be far more extended. We examine this behaviour in detail for the recent short gamma-ray burst GRB 170817A observed in coincidence with the gravitational wave event GW170817.

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Biscoveanu, Sylvia, Eric Thrane, and Salvatore Vitale. "Constraining Short Gamma-Ray Burst Jet Properties with Gravitational Waves and Gamma-Rays." Astrophysical Journal 893, no. 1 (2020): 38. http://dx.doi.org/10.3847/1538-4357/ab7eaf.

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Sommer, M., D. L. Bertsch, B. L. Dingus, et al. "High-energy gamma rays from the intense 1993 January 31 gamma-ray burst." Astrophysical Journal 422 (February 1994): L63. http://dx.doi.org/10.1086/187213.

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Axelsson, M., M. Ajello, M. Arimoto, et al. "GRB 221009A: The B.O.A.T. Burst that Shines in Gamma Rays." Astrophysical Journal Supplement Series 277, no. 1 (2025): 24. https://doi.org/10.3847/1538-4365/ada272.

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Abstract We present a complete analysis of Fermi Large Area Telescope (LAT) data of GRB 221009A, the brightest gamma-ray burst (GRB) ever detected. The burst emission above 30 MeV detected by the LAT preceded, by 1 s, the low-energy (<10 MeV) pulse that triggered the Fermi Gamma-Ray Burst Monitor (GBM), as has been observed in other GRBs. The prompt phase of GRB 221009A lasted a few hundred seconds. It was so bright that we identify a bad time interval of 64 s caused by the extremely high flux of hard X-rays and soft gamma rays, during which the event reconstruction efficiency was poor and the dead time fraction quite high. The late-time emission decayed as a power law, but the extrapolation of the late-time emission during the first 450 s suggests that the afterglow started during the prompt emission. We also found that high-energy events observed by the LAT are incompatible with synchrotron origin, and, during the prompt emission, are more likely related to an extra component identified as synchrotron self-Compton (SSC). A remarkable 400 GeV photon, detected by the LAT 33 ks after the GBM trigger and directionally consistent with the location of GRB 221009A, is hard to explain as a product of SSC or TeV electromagnetic cascades, and the process responsible for its origin is uncertain. Because of its proximity and energetic nature, GRB 221009A is an extremely rare event.

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Chadwick, P. M., J. E. Dickinson, M. R. Dickinson, et al. "A burst of pulsed VHE gamma rays from AE Aquarii." Astroparticle Physics 4, no. 2 (1995): 99–111. http://dx.doi.org/10.1016/0927-6505(95)00035-1.

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ZHANG, BING. "GAMMA-RAY BURST PROMPT EMISSION." International Journal of Modern Physics D 23, no. 02 (2014): 1430002. http://dx.doi.org/10.1142/s021827181430002x.

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The origin of gamma-ray burst (GRB) prompt emission, bursts of γ-rays lasting from shorter than one second to thousands of seconds, remains not fully understood after more than 40 years of observations. The uncertainties lie in several open questions in the GRB physics, including jet composition, energy dissipation mechanism, particle acceleration mechanism and radiation mechanism. Recent broad-band observations of prompt emission with Fermi sharpen the debates in these areas, which stimulated intense theoretical investigations invoking very different ideas. I will review these debates, and argue that the current data suggest the following picture: A quasi-thermal spectral component originating from the photosphere of the relativistic ejecta has been detected in some GRBs. Even though in some cases (e.g. GRB 090902B) this component dominates the spectrum, in most GRBs, this component either forms a sub-dominant "shoulder" spectral component in the low energy spectral regime of the more dominant "Band" component, or is not detectable at all. The main "Band" spectral component likely originates from the optically thin region due to synchrotron radiation. The diverse magnetization in the GRB central engine is likely the origin of the observed diverse prompt emission properties among bursts.

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Vilmer, N. "Solar Hard X-Ray and Gamma-Ray Observations from GRANAT." International Astronomical Union Colloquium 142 (1994): 611–21. http://dx.doi.org/10.1017/s0252921100077885.

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AbstractHard X-rays and gamma-rays are the most direct signature of the energetic electrons and ions which are accelerated during solar flares. Since the beginning of 1990 the PHEBUS instrument and the SIGMA anticoincidence shield aboard GRANAT have provided hard X-ray and gamma-ray observations of solar bursts in the energy range 0.075-124 and 0.200-15 MeV, respectively. After a brief description of the experiments, we present some results obtained on solar bursts recorded in 1990 and 1991 June. Special emphasis is given to the results related with particle acceleration during solar flares.The first part of the review is devoted to the constraints obtained on the electron acceleration timescale through the analysis of the temporal characteristics of the bursts. Combined studies of hard X-ray and gamma-ray emissions from PHEBUS and radio emissions from the Nançay Multifrequency Radioheliograph are used to infer constraints on the coronal magnetic topology involved in flares. The characteristics (location, spectrum) of the radio-emitting sources are found to vary within a flare from one hard X-ray peak to the other. Hard X-ray and gamma-ray burst onsets and rapid increases of the > 10 MeV emission are coincident with changes in the associated radio emission pattern. These results will be discussed in the context of the flare energy release.The second part of the paper concerns the heliocentric angle distribution of > 10 MeV events and presents more detailed observations of some of the largest flares in the gamma-ray line and the high-energy domains produced by ultrarelativistic electrons and > 100 MeV nucleon−1 ions. The PHEBUS observations of the gamma-ray line flare of 11 June 1991 have been used to deduce the hardness of the accelerated ion spectrum. The link between the main part of the flare and the late long-lasting >50 MeV emission detected by EGRET/COMPTON is discussed. Finally some observations of the large 1990 May 24 flare which produced a large neutron event at ground level are presented.Subject headings: acceleration of particles — Sun: flares — Sun: radio radiation — Sun: X-rays, gamma rays

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DERISHEV, E. V. "LIMITS TO THE PHYSICAL PARAMETERS IN EXTRAGALACTIC GAMMA-RAY SOURCES." International Journal of Modern Physics D 18, no. 10 (2009): 1523–27. http://dx.doi.org/10.1142/s0218271809015448.

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We examine several constraints on the physical parameters in active galactic nuclei and gamma-ray burst, originating from the assumption that these sources are efficient in converting their energy into gamma-rays. It is shown that in most cases these constraints may be reformulated in terms of bounds on the jet Lorentz factor, for which both the lower and the upper limits can be evaluated.

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Baring, Matthew G. "Gamma-Ray Burst Spectral Breaks and Source Beaming." International Astronomical Union Colloquium 142 (1994): 899–903. http://dx.doi.org/10.1017/s0252921100078283.

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AbstractThe principal discovery of the ComptonGamma-Ray Observatory(GRO) concerning gamma-ray bursts is that these sources are isotropic but with a comparative deficiency of fainter sources, suggesting that they are probably cosmological in origin. If they are at such large distances from Earth then they are extremely luminous and compact. A consequence of this is that two-photon pair production attenuation of the gamma-ray continuum cannot be avoided unless the source radiation is substantially beamed. Most sources do not display gamma-ray turnovers although a few GRB detected byGROexhibit distinct spectral breaks in the MeV range. A derivation of the relationship defining of the degree of beaming in burst sources with spectral breaks due toγ-γattenuation, as a function of source spectral index and break energy, is presented. It is found that sources at distances of ~1 Gpc must typically be beamed with bulk Lorentz factors of around 103-104, indicating powerful bulk acceleration in bursts, although these Lorentz factors are reduced markedly for steep source spectra. Since the source spectra are not strongly Comptonized, such beaming will blueshift the γ-γ attenuation breaks to energies much higher than 1 MeV; an absolute lower bound to the source bulk Lorentz factor is determined from this additional constraint. This blueshifting suggests that those sources with MeV breaks may not be cosmological, or that their breaks are produced by a mechanism that dominates γ-γ attenuation at these energies.Subject headings:gamma-rays: bursts — radiation mechanisms: nonthermal

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Wang, Yun, Tian-Ci Zheng, and Zhi-Ping Jin. "GRB 220426A: A Thermal Radiation–Dominated Gamma-Ray Burst." Astrophysical Journal 940, no. 2 (2022): 142. http://dx.doi.org/10.3847/1538-4357/aca017.

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Abstract The physical composition of the ejecta of gamma-ray bursts (GRBs) remains an open question. The radiation mechanism of the prompt gamma rays is also in debate. This problem can be solved for the bursts hosting distinct thermal radiation. However, the events with dominant thermal spectral components are still rare. In this work, we focus on GRB 220426A, a recent event detected by the Fermi Gamma-ray Burst Monitor. The time-resolved and time-integrated data analyses yield very hard low-energy spectral indices and rather soft high-energy spectral indices. This means that the spectra of GRB 220426A are narrowly distributed. And the Bayesian inference results are in favor of the multicolor blackbody model. The physical properties of the relativistic outflow are calculated. Assuming a redshift z = 1.4, the bulk Lorentz factors Γ of the shells are found to be between 274 − 18 + 24 and 827 − 71 + 100 , and the corresponding photosphere radii R ph are in the range of 1.83 − 0.50 + 0.52 × 10 11 and 2.97 − 0.15 + 0.14 × 10 12 cm. Similar to GRB 090902B, the time-resolved properties of GRB 220426A satisfy the observed Γ–L and E p –L correlations, where L is the luminosity of the prompt emission and E p is the spectral peak energy.

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Thakur, Pranali, Gauri Datar, Geeta Vichare, and Selvaraj Chelliah. "Effect of the brightest gamma-ray burst (GRB 221009A) on low energy gamma-ray counts at sea level." Journal of Cosmology and Astroparticle Physics 2024, no. 04 (2024): 086. http://dx.doi.org/10.1088/1475-7516/2024/04/086.

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Abstract A gamma-ray burst, named GRB 221009A, occurred on 9 October 2022 and is the brightest ever observed GRB, whose frequency is now estimated as once in 10,000 years. This GRB was reported to be observed from many space missions, VLF receivers, and ground observations in optical and radio data. Additionally, a strikingly large number of very high energy (VHE) photons associated with this GRB were observed by the gamma-ray and cosmic ray observatory LHAASO. Though gamma-rays of cosmic origin usually tend to be absorbed by the atmosphere, the high fluence of this GRB, along with the observation of more than 5000 VHE photons (0.5 to 18 TeV) by LHAASO from the ground, emphasises the need to explore other possible ground observations of this GRB. With RA = 288.3° and Dec = 19.8°, the exceptionally bright fluence of this GRB was geographically centred on India. The present paper examines the effect of this GRB using gamma-ray data in a low energy range (0.2–6) MeV obtained using NaI (Tl) detectors located at Tirunelveli (Geographic coordinates: 8.71°N, 77.76°E), India. We report no significant change in the observations associated with GRB 221009A. We discuss the extent of attenuation of gamma-rays in the atmosphere that could explain the reported observations. Further, we investigate the likelihood of ground observation of gamma-rays (< 10 MeV) for a much more intense hypothetical GRB and estimate the parameters, such as distance, fluence, and isotropic energy of such a GRB.

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Yang, Chen, Sai Wang, Meng-Lin Zhao, and Xin Zhang. "Search for the Hawking radiation of primordial black holes: prospective sensitivity of LHAASO." Journal of Cosmology and Astroparticle Physics 2024, no. 10 (2024): 083. http://dx.doi.org/10.1088/1475-7516/2024/10/083.

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Abstract Primordial black holes (PBHs), more generally, BHs, undergo evaporation and, in principle, will end their lives in bursts of very high-energy gamma rays. The notable aspect of the PBHs with an initial mass of ∼ 1014 g is that they are expected to end their lives today. In this work, we assess the potential sensitivity of the Large High Altitude Air Shower Observatory (LHAASO) in detecting the local burst rate density of PBHs. Our results suggest that LHAASO is capable of probing for PBH bursts within a proximity of ∼ 0.1 pc from the Sun, measuring a local burst rate density of ∼ 1200 (or 700)pc-3 yr-1 with 99% confidence during a 3-year (or 5-year) observational campaign. This level of sensitivity surpasses the most rigorous observational constraint provided by the High Altitude Water Cherenkov Observatory (HAWC) by an order of magnitude. Additionally, we propose data analysis strategies for LHAASO to optimize the search for PBHs and reach its potential detection limits.

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Gupta, Nayantara. "On the gamma ray burst origin of extremely energetic cosmic rays." Astroparticle Physics 31, no. 5 (2009): 359–65. http://dx.doi.org/10.1016/j.astropartphys.2009.03.006.

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HORVATH, J. E. "ENERGETICS OF THE SUPERFLARE FROM SGR1806-20 AND A POSSIBLE ASSOCIATED GRAVITATIONAL WAVE BURST." Modern Physics Letters A 20, no. 36 (2005): 2799–804. http://dx.doi.org/10.1142/s0217732305018359.

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We discuss in this paper the energetics of large gamma-ray superflares observed from Soft-Gamma Repeater sources. The last recorded event has in fact ruled out some models for the energy release. For the first time actual information about a possible associated gravitational wave emission may have been gathered from the LIGO data, even in the case that most of the energy was emitted in gamma-rays. Even upper limits on the amplitude of the latter h at the expected frequency fc≤2 kHz may be useful to further constrain the remaining mechanisms.

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GALANTE, DOUGLAS, and JORGE ERNESTO HORVATH. "QUANTITATIVE BIOLOGICAL EFFECTS OF GAMMA-RAY BURSTS." International Journal of Modern Physics D 16, no. 02n03 (2007): 509–14. http://dx.doi.org/10.1142/s0218271807010328.

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We present a unified, quantitative synthesis of analytical and numerical calculations of the effects caused on an Earth-like planet by a Gamma-Ray Burst (GRB), considering atmospheric and biological implications. The main effects of the illumination by a GRB are classified in four distinct phenomena and analyzed separately, namely: direct γ radiation transmission, UV flash, ozone layer depletion and cosmic rays. The "effectiveness" of each of these effects is compared and lethal distances for significant biological damage are given for each one. We find that the first three effects have potential to cause global environmental changes and biospheric damages, even if the source is located at a great distance (perhaps 100 kpc). In contrast, cosmic rays would only be a serious threat for very close sources.

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Totani, Tomonori. "T[CLC]e[/CLC]V Burst of Gamma-Ray Bursts and Ultra–High-Energy Cosmic Rays." Astrophysical Journal 509, no. 2 (1998): L81—L84. http://dx.doi.org/10.1086/311772.

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He, Hao-Ning, B. Thoedore Zhang, and Yi-Zhong Fan. "A Detectable Ultra-high-energy Cosmic-Ray Outburst from GRB 221009A." Astrophysical Journal 963, no. 2 (2024): 109. http://dx.doi.org/10.3847/1538-4357/ad2352.

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Abstract Gamma-ray bursts (GRBs) have been proposed as one of the promising sources of ultra-high-energy cosmic rays (UHECRs), but observational evidence is still lacking. The nearby brightest of all time GRB 221009A, a once in 1000 yr event, is able to accelerate protons to ∼103 EeV, and then generate extremly energetic neutrons via the photomeson production interaction. Protons arriving at the Milky Way are dominated by neutron-decay-induced protons. The intergalactic magnetic fields would not yield a sizable delay of the ≥10 EeV cosmic rays if its strength is ≲10−13 G, while Galactic magnetic fields would cause a significant time delay. We predict that a UHECR burst from GRB 221009A would be detectable by the Pierre Auger Observatory and the TA×4, within ∼10 yr. The detection of such a UHECR outburst will provide the direct evidence for UHECR acceleration in GRBs.

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Ruffini, Remo, and Costantino Sigismondi. "Fitting the Crab Supernova with a Gamma-Ray Burst." Universe 10, no. 7 (2024): 275. http://dx.doi.org/10.3390/universe10070275.

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Here, we reconsider the historical data, assuming a gamma-ray burst (GRB) as its source. A Supernova correlated with the GRB explains well the fading time observed by the ancient Chinese astronomers in the daytime and the nighttime, while the GRB power law explains the present X-rays and GeV emission of the Crab. On the grounds of a recent understanding of the first episode of binary-driven hypernova GRB (BDHN GRB) in terms of the collapse of a ten solar masses core, we propose the possible identification of the real Supernova event at an earlier time than Chinese chronicles. This work allows a new understanding of the significance of historical astronomical observations, including a fireball due to gamma-ray air shower observation and a plague of acute radiation syndrome, documented with several thousands of victims in the Eurasian area (Egypt, Iraq, and Syria).

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Waxman, Eli. "High‐Energy Cosmic Rays from Gamma‐Ray Burst Sources: A Stronger Case." Astrophysical Journal 606, no. 2 (2004): 988–93. http://dx.doi.org/10.1086/383116.

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Waxman, Eli. "High Energy Cosmic-Rays and Neutrinos from Cosmological Gamma-Ray Burst Fireballs." Physica Scripta T85, no. 1 (2000): 117. http://dx.doi.org/10.1238/physica.topical.085a00117.

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Piano, Giovanni, Luca Foffano, and Marco Tavani. "AGILE observations of the ultra-luminous GRB 221009A." EPJ Web of Conferences 319 (2025): 06006. https://doi.org/10.1051/epjconf/202531906006.

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The ultra-luminous, long-duration transient event GRB 221009A was detected by several observatories - as the most luminous gamma-ray burst ever observed - from radio to VHE gamma rays, up to tens of TeV. AGILE detected an extraordinary incoming flux of hard X-ray and high-energy gammaray photons during this unprecedented event. The high-energy emission (from tens of keV up to GeV energies) has been recorded by the AGILE detectors with an almost-continuous time coverage, monitoring the transition between the prompt and the afterglow phase, up to ~20 ks after the onset of the GRB. AGILE time-resolved spectra and light curves are presented in a multi-frequency context, focused on the observed high-energy component of this intense GRB. The AGILE simultaneous hard-X/gamma-ray observations during the key phases of the burst will be crucial to give robust constraints to the physical evolution of the GRB’s high-energy emission.

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Li, Jia-Sheng, Mi-Xiang Lan, and Hao-Bing Wang. "Multiwavelength Emission of the Gamma-Ray Burst Prompt Phase. I. Time-resolved and Time-integrated Polarizations." Astrophysical Journal 970, no. 1 (2024): 10. http://dx.doi.org/10.3847/1538-4357/ad4a6a.

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Abstract The time-integrated polarization degree (PD) in the prompt optical band of a gamma-ray burst (GRB) was predicted to be less than 20%, while the time-resolved one can reach as high as 75% in the photosphere model. Polarizations in the optical band during the GRB prompt phase have not previously been studied in the framework of the magnetic reconnection model. Here, a three-segment power law of the energy spectrum is used to reconstruct the Stokes parameters of the magnetic reconnection model. Multiwavelength light curves and polarization curves from the optical band to MeV gamma rays in the GRB prompt phase are studied. We found that, depending mainly on the jet dynamics, there is a long-lasting high-PD phase in all calculated energy bands for the typical parameter sets. The time-resolved PD could be as high as 50%, while the time-integrated one is roughly 17% in the optical band. The time-resolved PD in X-rays can reach 60% and the time-integrated one is around 30%–40%. The evolution of polarization angle (PA) is random in both optical and gamma-ray bands for the photosphere model, while it is roughly constant in the synchrotron models. Therefore, future time-resolved PA observations in the prompt optical or gamma-ray band could distinguish between the photosphere and synchrotron models.

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Makino, F. "X-Ray Astronomy Satellite Ginga." International Astronomical Union Colloquium 123 (1990): 41–48. http://dx.doi.org/10.1017/s0252921100076880.

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AbstractThe X-ray astronomy satellite Ginga carries three scientific instruments, the Large Area proportional Counters (LAC), All Sky X-ray Monitor (ASM) and Gamma-ray Burst Detector (GBD). The LAC is the main instrument with an effective area of 4000 cm2 giving it the highest sensitivity to hard X-rays so far achieved. Ginga observed about 250 targets up to the end of 1989.

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Liu, Ruo-Yu, Hai-Ming Zhang, and Xiang-Yu Wang. "Constraints on Gamma-Ray Burst Models from GRB 221009A: GeV Gamma Rays versus High-energy Neutrinos." Astrophysical Journal Letters 943, no. 1 (2023): L2. http://dx.doi.org/10.3847/2041-8213/acaf5e.

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Abstract Gamma-ray bursts (GRBs) are generally believed to be efficient particle accelerators. In the presence of energetic protons in a GRB jet, interactions between these protons and the intense radiation field of the GRB are supposed to induce an electromagnetic cascade. Electrons/positrons generated in the cascade will produce an additional spectrum of a robust feature, which is in the form of a power-law distribution up to a GeV regime with an index of ≲2. We suggest that measurements of the Fermi Large Area Telescope at the GeV band can provide independent constraints on the key GRB model parameters such as the dissipation radius, the jet’s bulk Lorentz factor, and the baryon loading factor. Taking GRB 221009A, the brightest GRB ever detected, as an example, we show that the constraints from GeV gamma-ray emission may be more stringent than that from the neutrino observation, providing us with deep insight into the origin of GRBs.

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LE COULTRE, P. "SEARCH FOR BURST SIGNALS FROM POINT SOURCES." International Journal of Modern Physics A 20, no. 29 (2005): 6962–64. http://dx.doi.org/10.1142/s0217751x05030600.

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A sky survey for flaring point sources emitting high energy gamma rays has been performed with the L 3+ C underground muon spectrometer at LEP, CERN. Data were collected from mid July to October 1999 and from April to November 2000. No signal excesses in any direction have been found with muons above 20, 30, 50 and 100 GeV within one day and longer time windows. The steady muon flux sensitivity is of the order of a few times 10-9 cm-2 s-1 for muon energies above 20 GeV, and between 2 × 10-11 and 5 × 10-10 cm -2 s -1 for muon energies above 20 GeV depending on the source position.

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Lunardini, Cecilia, Joshua Loeffler, Mainak Mukhopadhyay, Matthew J. Hurley, Ebraheem Farag, and F. X. Timmes. "Photons from Neutrinos: The Gamma-Ray Echo of a Supernova Neutrino Burst." Astrophysical Journal 969, no. 2 (2024): 149. http://dx.doi.org/10.3847/1538-4357/ad4546.

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Abstract When a star undergoes core collapse, a vast amount of energy is released in a ∼10 s long burst of neutrinos of all species. Inverse beta decay in the star’s hydrogen envelope causes an electromagnetic cascade that ultimately results in a flare of gamma rays—an “echo” of the neutrino burst—at the characteristic energy of 0.511 MeV. We study the phenomenology and detectability of this flare. Its luminosity curve is characterized by a fast, seconds-long rise and an equally fast decline, with a minute- or hour-long plateau in between. For a near-Earth star (distance D ≲ 1 kpc) the echo will be observable at near future gamma-ray telescopes with an effective area of 103 cm2 or larger. Its observation will inform us on the envelope size and composition. In conjunction with the direct detection of the neutrino burst, it will also give information on the neutrino emission away from the line of sight and will enable tests of neutrino propagation effects between the stellar surface and Earth.

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