Astroparticle Physics最新文献

{"title":"Evolution of realistic neutron star in the framework of f(Q) gravity","authors":"Samprity Das ,&nbsp;Surajit Chattopadhyay","doi":"10.1016/j.astropartphys.2024.103053","DOIUrl":"10.1016/j.astropartphys.2024.103053","url":null,"abstract":"<div><div>This work analyzes and evaluates a few realistic compact objects in the presence of a gravitational interaction between two particles with a nonmetricity <span><math><mi>Q</mi></math></span>. In the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>)</mo></mrow></mrow></math></span> gravity framework, we have selected the anisotropic equation of motion and have determined <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>)</mo></mrow></mrow></math></span> to be a linear function of nonmetricity <span><math><mi>Q</mi></math></span>. To evaluate the field equations in our work, we have opted to employ the Krori–Barua metric. We calculated the anisotropic factor for each of the four compact objects and found that the anisotropic component is positive and increases monotonically and interpreted that the nuclear force can oppose the gravitational attraction. At last, the relationship between mass and radius has been determined and illustrated visually. We have noted that the compactness of the pulsars LMC X-4, SMC X-4, Cen X-3, and Vela X-1 is inside the Buchdahl’s limit for varying values of <span><math><mi>a</mi></math></span>. This has led to the interpretation that these pulsars are neutron stars in a modified gravity background of <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>Q</mi><mo>)</mo></mrow></mrow></math></span>. In addition, we calculated the model mass and, using thirty distinct choices of <span><math><mi>a</mi></math></span>, ran the Chi-Square test to see if there was a noticeable difference between the observed and model-generated masses. We have also looked at how the surface redshift has changed over time and whether the compact objects in our model that were previously described are compact.</div></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"165 ","pages":"Article 103053"},"PeriodicalIF":4.2,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 EUSO-SPB2 fluorescence telescope for the detection of Ultra-High Energy Cosmic Rays","authors":"James H. Adams Jr. ,&nbsp;Denis Allard ,&nbsp;Phillip Alldredge ,&nbsp;Luis Anchordoqui ,&nbsp;Anna Anzalone ,&nbsp;Matteo Battisti ,&nbsp;Alexander A. Belov ,&nbsp;Mario Bertaina ,&nbsp;Peter F. Bertone ,&nbsp;Sylvie Blin-Bondil ,&nbsp;Julia Burton ,&nbsp;Francesco S. Cafagna ,&nbsp;Marco Casolino ,&nbsp;Karel Černý ,&nbsp;Mark J. Christl ,&nbsp;Roberta Colalillo ,&nbsp;Hank J. Crawford ,&nbsp;Alexandre Creusot ,&nbsp;Austin Cummings ,&nbsp;Rebecca Diesing ,&nbsp;Roy Young","doi":"10.1016/j.astropartphys.2024.103046","DOIUrl":"10.1016/j.astropartphys.2024.103046","url":null,"abstract":"<div><div>The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2) flew on May 13th and 14th of 2023. Consisting of two novel optical telescopes, the payload utilized next-generation instrumentation for the observations of extensive air showers from near space. One instrument, the fluorescence telescope (FT) searched for Ultra-High Energy Cosmic Rays (UHECRs) by recording the atmosphere below the balloon in the near-UV with a <span><math><mrow><mn>1</mn><mspace></mspace><mi>μ</mi><mi>s</mi></mrow></math></span> time resolution using 108 multi-anode photomultiplier tubes with a total of 6912 channels. Validated by pre-flight measurements during a field campaign, the energy threshold was estimated around 2 EeV with an expected event rate of approximately 1 event per 10 h of observation. Based on the limited time afloat, the expected number of UHECR observations throughout the flight is between 0 and 2. Consistent with this expectation, no UHECR candidate events have been found. The majority of events appear to be detector artifacts that were not rejected properly due to a shortened commissioning phase. Despite the earlier-than-expected termination of the flight, data were recorded which provide insights into the detectors stability in the near-space environment as well as the diffuse ultraviolet emissivity of the atmosphere, both of which are impactful to future experiments.</div></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"165 ","pages":"Article 103046"},"PeriodicalIF":4.2,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Non-parametric analysis for the dark matter density evolution","authors":"Z.C. Santana ,&nbsp;R.F.L. Holanda ,&nbsp;R. Silva","doi":"10.1016/j.astropartphys.2024.103052","DOIUrl":"10.1016/j.astropartphys.2024.103052","url":null,"abstract":"<div><div>In this paper, we investigate a potential departure in the standard dark matter density evolution law, <span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>d</mi><mi>m</mi></mrow></msub><mo>=</mo><msub><mrow><mi>ρ</mi></mrow><mrow><mi>d</mi><mi>m</mi><mo>,</mo><mn>0</mn></mrow></msub><msup><mrow><mrow><mo>(</mo><mn>1</mn><mo>+</mo><mi>z</mi><mo>)</mo></mrow></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span>. The method involves considering a deformed evolution model, denoted as <span><math><mrow><msub><mrow><mi>ρ</mi></mrow><mrow><mi>d</mi><mi>m</mi></mrow></msub><mo>=</mo><msub><mrow><mi>ρ</mi></mrow><mrow><mi>d</mi><mi>m</mi><mo>,</mo><mn>0</mn></mrow></msub><msup><mrow><mrow><mo>(</mo><mn>1</mn><mo>+</mo><mi>z</mi><mo>)</mo></mrow></mrow><mrow><mn>3</mn></mrow></msup><mi>f</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span>, and searching for the presence of any deviation (<span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow><mo>≠</mo><mn>1</mn></mrow></math></span>). As one may see, <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span> is a general function that parametrizes a possible digression from the standard law. We use data of baryon acoustic oscillations, type I Supernovae luminosity distances, and galaxy cluster gas mass fraction observations to reconstruct <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></math></span> through an approach that is not dependent on the cosmological model or the so-called Gaussian process regression. Unlike previous works, it enables us to investigate a possible deviation without using a specific function to describe it. We have obtained <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow><mo>=</mo><mn>1</mn></mrow></math></span>, the standard model scenario, within <span><math><mrow><mn>2</mn><mi>σ</mi></mrow></math></span> c.l. in all the considered cases.</div></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"165 ","pages":"Article 103052"},"PeriodicalIF":4.2,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142313019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Modeling hadronic interactions in ultra-high-energy cosmic rays within astrophysical environments: A parametric approach","authors":"Antonio Condorelli ,&nbsp;Sergio Petrera","doi":"10.1016/j.astropartphys.2024.103047","DOIUrl":"10.1016/j.astropartphys.2024.103047","url":null,"abstract":"<div><p>Interactions of ultra-high energy cosmic-rays (UHECRs) accelerated in astrophysical environments have been shown to shape the energy production rate of nuclei escaping from the confinement zone. To address the influence of hadronic interactions, Hadronic Interaction Models (HIMs) come into play. In this context, we present a parameterization capable of capturing the outcomes of two distinct HIMs, namely EPOS-LHC and Sibyll2.3d, in terms of secondary fluxes, including escaping nuclei, nucleons, neutrinos, photons, and electrons. Our parameterization is systematically evaluated against the source codes, both at fixed energy and mass, as well as in a physical case scenario. The comparison demonstrates that our parameterization aligns well with the source codes, establishing its reliability as a viable alternative for analytical or fast Monte Carlo approaches dedicated to the study of UHECR propagation within source environments. This suggests the potential for utilizing our parameterization as a practical substitute in studies focused on the intricate dynamics of ultra-high energy cosmic rays.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"165 ","pages":"Article 103047"},"PeriodicalIF":4.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142240344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Data quality control system and long-term performance monitor of LHAASO-KM2A","authors":"Zhen Cao ,&nbsp;F. Aharonian ,&nbsp;Axikegu ,&nbsp;Y.X. Bai ,&nbsp;Y.W. Bao ,&nbsp;D. Bastieri ,&nbsp;X.J. Bi ,&nbsp;Y.J. Bi ,&nbsp;W. Bian ,&nbsp;A.V. Bukevich ,&nbsp;Q. Cao ,&nbsp;W.Y. Cao ,&nbsp;Zhe Cao ,&nbsp;J. Chang ,&nbsp;J.F. Chang ,&nbsp;A.M. Chen ,&nbsp;E.S. Chen ,&nbsp;H.X. Chen ,&nbsp;Liang Chen ,&nbsp;Lin Chen ,&nbsp;X. Zuo","doi":"10.1016/j.astropartphys.2024.103029","DOIUrl":"10.1016/j.astropartphys.2024.103029","url":null,"abstract":"<div><p>The KM2A is the largest sub-array of the Large High Altitude Air Shower Observatory (LHAASO). It consists of 5216 electromagnetic particle detectors (EDs) and 1188 muon detectors (MDs). The data recorded by the EDs and MDs are used to reconstruct primary information of cosmic-ray and gamma-ray showers. To ensure the reliability of the LHAASO-KM2A data, a three-level quality control system has been established. It is used to monitor the status of detector units, stability of reconstructed parameters and the performance of the array based on observations of the Crab Nebula and Moon shadow. This paper will introduce the control system and its application on the LHAASO-KM2A data collected from August 2021 to July 2023. During this period, the pointing and angular resolution of the array were stable. From the observations of the Moon shadow and Crab Nebula, the results achieved using the two methods are consistent with each other. For example, according to the observation of the Crab Nebula with KM2A at energies from 25 TeV to 100 TeV, the time averaged pointing errors are estimated to be <span><math><mrow><mo>−</mo><mn>0</mn><mo>.</mo><mn>003</mn><mo>°</mo><mo>±</mo><mn>0</mn><mo>.</mo><mn>005</mn><mo>°</mo></mrow></math></span> and <span><math><mrow><mn>0</mn><mo>.</mo><mn>001</mn><mo>°</mo><mo>±</mo><mn>0</mn><mo>.</mo><mn>006</mn><mo>°</mo></mrow></math></span> in the R.A. and Dec directions, respectively.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"164 ","pages":"Article 103029"},"PeriodicalIF":4.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0927650524001063/pdfft?md5=2e46eeda20db2bab268c8f740a474474&pid=1-s2.0-S0927650524001063-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Simulations of neutron activation background for the NνDEx experiment","authors":"Qianming Wang ,&nbsp;Zeyu Huang ,&nbsp;Pengchong Hu ,&nbsp;Emilio Ciuffoli","doi":"10.1016/j.astropartphys.2024.103039","DOIUrl":"10.1016/j.astropartphys.2024.103039","url":null,"abstract":"<div><p>An extremely low-background environment is a crucial requirement for any neutrinoless double beta decay experiment. Neutrons are very difficult to stop, because they can pass through the shielding and activate nuclei in the detector, even inside the fiducial volume itself. Using Geant4 simulations we have studied the neutron background for N<span><math><mi>ν</mi></math></span>DEx-100 and the most efficient way to reduce it. Using a 60 cm thick external high-density polyethylene (HDPE) shielding the neutron background can be reduced down to <span><math><mrow><mn>0</mn><mo>.</mo><mn>24</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>06</mn></mrow></math></span> events/year, lower than the background rate due to natural radioactivity (0.42 events/year), which was used as a benchmark for these calculations. The amount of HDPE needed can be significantly reduced by placing a filler in the empty space between the lead shielding and the steel vessel; in this way, it is sufficient to add 20 cm external HDPE shielding to reduce the neutron background down to <span><math><mrow><mn>0</mn><mo>.</mo><mn>15</mn><mo>±</mo><mn>0</mn><mo>.</mo><mn>05</mn></mrow></math></span> events/year.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"164 ","pages":"Article 103039"},"PeriodicalIF":4.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0927650524001166/pdfft?md5=cd28f33708a1744c281c2f8d44767f41&pid=1-s2.0-S0927650524001166-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142084371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"On the same origin of quantum physics and general relativity from Riemannian geometry and Planck scale formalism","authors":"Chavis Srichan ,&nbsp;Pobporn Danvirutai ,&nbsp;Adrian David Cheok ,&nbsp;Jun Cai ,&nbsp;Ying Yan","doi":"10.1016/j.astropartphys.2024.103036","DOIUrl":"10.1016/j.astropartphys.2024.103036","url":null,"abstract":"<div><p>It has been a long time to reconcile quantum physics and general relativity. To date, no globally accepted theory has been proposed to explain all physical observations. In this work, we reformulated the Riemannian geometry in terms of curvature and energy tensors using the Planck scale formalism. The proposed equation can be transformed into Dirac equations in electrodynamic and chromodynamic fields with a reduction in the background curvature. We redefined the mass and charge of leptons in terms of the interactions between the energy of the field and the curvature of the spacetime. The obtained equation is covariant in space–time and invariant with respect to any Planck scale. Therefore, the constants of the universe can be reduced to only two quantities: Planck length and Planck time. We proved that the Einstein field equation from general relativity is actually a relativistic quantum mechanical equation. We further modeled the universe using the equation with Einstein's lambda formalism and found that the universe dynamics could be considered as harmonic oscillators entangled with lambda curvature. This equation can be used to describe the energy transfer between two entangled spacetimes between the same universe and between any two universes (ER=EPR). The singularity of black holes can be avoided at the Planck scale, because space and time are no longer entangled. This equation predicts that information of light from the entangled universe can be transferred to our universe. The gravitational wave background was predicted, and its spectrum was close to that of the observation.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"164 ","pages":"Article 103036"},"PeriodicalIF":4.2,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0927650524001130/pdfft?md5=59636c791b6277b2dc667639eaeecef0&pid=1-s2.0-S0927650524001130-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142098979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Control of the laser frequency in the Virgo interferometer: Dynamic noise budgeting for controller optimization","authors":"Mathyn van Dael ,&nbsp;Julia Casanueva ,&nbsp;Gert Witvoet ,&nbsp;Bas Swinkels ,&nbsp;Diego Bersanetti ,&nbsp;Manuel Pinto ,&nbsp;Paolo Ruggi ,&nbsp;Maddalena Mantovani ,&nbsp;Camilla de Rossi ,&nbsp;Piernicola Spinicelli ,&nbsp;Mattia Boldrini ,&nbsp;Tom Oomen","doi":"10.1016/j.astropartphys.2024.103028","DOIUrl":"10.1016/j.astropartphys.2024.103028","url":null,"abstract":"<div><p>This paper presents a framework for the derivation of a noise budget and the subsequent utilization in the optimization of the control design, using the laser frequency stabilization loop in the Virgo interferometer, which is a complex nested feedback system, as an experimental case study. First, the system dynamics and noise sources are modeled and experimentally verified to produce the noise budget, after which an optimization problem using the <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> norm is formulated and tailored to the specific design requirements for the detector. The structure of the synthesized controller is then used to produce an improved control design. Experimental verification of the developed controller on the Virgo interferometer shows roughly a factor 3 reduction in root-mean-square error, illustrating the effectiveness of the presented method.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"164 ","pages":"Article 103028"},"PeriodicalIF":4.2,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0927650524001051/pdfft?md5=f8dc056c4c825131ef0ee32f69698fa1&pid=1-s2.0-S0927650524001051-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141984549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Constraining cosmological parameters with viscous modified chaplygin gas and generalized cosmic chaplygin gas models in Horava–Lifshitz gravity: Utilizing late-time datasets","authors":"Sayani Maity ,&nbsp;Himanshu Chaudhary ,&nbsp;Ujjal Debnath ,&nbsp;S.K. Maurya ,&nbsp;G. Mustafa","doi":"10.1016/j.astropartphys.2024.103026","DOIUrl":"10.1016/j.astropartphys.2024.103026","url":null,"abstract":"<div><p>This study investigates accelerated cosmic expansion using the Viscous Modified Chaplygin Gas (VMMG) and Generalized Cosmic Chaplygin Gas (GCCM) within Horava–Lifshitz gravity. Our primary objective is to constrain essential cosmological parameters, such as the Hubble Parameter (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>) and Sound Horizon (<span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>d</mi></mrow></msub></math></span>). We incorporate recent datasets comprising 17 Baryon Acoustic Oscillation observations, 33 Cosmic Chronometer measurements, 40 Type Ia Supernovae data points, 24 quasar Hubble diagram data points, and 162 Gamma Ray Bursts data points. Additionally, we integrate the most recent determination of the Hubble constant (R22). We treat <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>d</mi></mrow></msub></math></span> as a free parameter, which offers several advantages, including mitigating bias, enhancing precision, and improving compatibility with various datasets. Consequently, by introducing random correlations in the covariance matrix during simulation, errors are effectively reduced. Our estimated values of the Hubble constant (<span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>) and <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>d</mi></mrow></msub></math></span> consistently align with measurements from both the Planck and SDSS experiments. Additionally, cosmographic tests offer valuable insights into the dynamics of various cosmological models, enriching our understanding of cosmic evolution. Statefinder diagnostics provide deeper insights into cosmic expansion dynamics, aiding in distinguishing between both cosmological frameworks. Furthermore, the <span><math><msub><mrow><mi>o</mi></mrow><mrow><mi>m</mi></mrow></msub></math></span> diagnostic test reveals that at late times, the VMMG model falls into the phantom region, while the Generalized GCCM falls into the quintessence region. Finally, the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) provide support for all models under consideration, indicating that each model offers a plausible explanation. Notably, the <span><math><mi>Λ</mi></math></span>CDM model emerges with the lowest AIC score, suggesting its relatively superior fit compared to others. Additionally, validation through the reduced <span><math><msubsup><mrow><mi>χ</mi></mrow><mrow><mtext>red</mtext></mrow><mrow><mn>2</mn></mrow></msubsup></math></span> statistic confirms satisfactory fits across all models, further reinforcing their credibility in explaining the observed data.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"164 ","pages":"Article 103026"},"PeriodicalIF":4.2,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0927650524001038/pdfft?md5=92e1d74b1f3b180d7074a5a2c0483df1&pid=1-s2.0-S0927650524001038-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Solar flare observations with the Radio Neutrino Observatory Greenland (RNO-G)","authors":"S. Agarwal ,&nbsp;J.A. Aguilar ,&nbsp;S. Ali ,&nbsp;P. Allison ,&nbsp;M. Betts ,&nbsp;D. Besson ,&nbsp;A. Bishop ,&nbsp;O. Botner ,&nbsp;S. Bouma ,&nbsp;S. Buitink ,&nbsp;M. Cataldo ,&nbsp;B.A. Clark ,&nbsp;A. Coleman ,&nbsp;K. Couberly ,&nbsp;S. de Kockere ,&nbsp;K.D. de Vries ,&nbsp;C. Deaconu ,&nbsp;M.A. DuVernois ,&nbsp;C. Glaser ,&nbsp;T. Glüsenkamp ,&nbsp;A. Zink","doi":"10.1016/j.astropartphys.2024.103024","DOIUrl":"10.1016/j.astropartphys.2024.103024","url":null,"abstract":"<div><p>The Radio Neutrino Observatory – Greenland (RNO-G) seeks discovery of ultra-high energy neutrinos from the cosmos through their interactions in ice. The science program extends beyond particle astrophysics to include radioglaciology and, as we show herein, solar observations, as well. Currently seven of 35 planned radio-receiver stations (24 antennas/station) are operational. These stations are sensitive to impulsive radio signals with frequencies between 80 and 700 MHz and feature a neutrino trigger threshold for recording data close to the thermal floor. RNO-G can also trigger on elevated signals from the Sun, resulting in nanosecond resolution time-domain flare data; such temporal resolution is significantly shorter than from most dedicated solar observatories. In addition to possible RNO-G solar flare polarization measurements, the Sun also represents an extremely useful above-surface calibration source.</p><p>Using RNO-G data recorded during the summers of 2022 and 2023, we find signal excesses during solar flares reported by the solar-observing Callisto network and also in coincidence with <span><math><mo>∼</mo></math></span>2/3 of the brightest excesses recorded by the SWAVES satellite. These observed flares are characterized by significant time-domain impulsivity. Using the known position of the Sun, the flare sample is used to calibrate the RNO-G absolute pointing on the radio signal arrival direction to sub-degree resolution. We thus establish the Sun as a regularly observed astronomical calibration source to provide the accurate absolute pointing required for neutrino astronomy.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"164 ","pages":"Article 103024"},"PeriodicalIF":4.2,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0927650524001014/pdfft?md5=f876aff9a99915b0bc2280db28087cf9&pid=1-s2.0-S0927650524001014-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141933628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}