Abstracts of Interest
Selected by:
Teddy
Abstract: 2503.01405
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Title:Neutrinos from dense environments
View PDF HTML (experimental)Abstract:Neutrinos from dense environments are unique laboratories for astrophysics, particle physics and many-body physics. They tell us about the last stages of the gravitational core-collapse and the explosion of massive stars. These elusive particles are also tightly linked to heavy elements synthesis in gravitational core-collapse supernovae and binary neutron star mergers, or play a pivotal role at the MeV epoch during the Universe expansion. We highlight theoretical and observational aspects of this interesting domain, in particular for the future measurement of neutrinos from the next core-collapse supernova, and of the diffuse supernova background, whose discovery might lie in the forthcoming future.
Abstract: 2503.01408
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Title:MIR: a general-relativistic resistive-magneto-hydrodynamic code to study the effect of resistivity in Neutron Star dynamics
View PDF HTML (experimental)Abstract:Electrical resistivity plays a fundamental role in many astrophysical systems, influencing the evolution of the magnetic field and energy dissipation processes. During the coalescence of two neutron stars, resistive effects can significantly affect the dynamics and gravitational and electromagnetic signatures associated with these events, such as gamma-ray bursts and kilonova emission. Here, we present our new code, named MIR. Developed within the EinsteinToolkit framework, MIR solves the general relativistic magnetohydrodynamic equations in 3D Cartesian coordinates and on a dynamical spacetime using the 3+1 Eulerian formalism, in both the ideal and resistive regimes, filling a crucial gap in the toolkit's capabilities.
Abstract: 2503.01583
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Title:Signature of hadronic emission in gamma-ray spectrum of B2 1308+326
View PDF HTML (experimental)Abstract:The Flat Spectrum Radio Quasar (FSRQ) B2\,1308+326 was in its highest $\gamma$-ray flaring state during 60260-60310\,MJD. During this period, the source was detected in very high energy (VHE) by the large-sized telescope (LST-1). We conducted a detailed broadband spectral study of this source using the simultaneous data available in optical/UV, X-ray, and $\gamma$-ray bands. For the broadband spectral study, we select two gamma-ray high flux states (59750-59800\,MJD, 60260-60310\,MJD) and one low flux state (59250-59320\,MJD). During the epochs, 59750-59800\,MJD (high flux state) and 59250-59320\,MJD (low flux state), the broadband spectral energy distribution (SED) is well fitted using one zone leptonic emission model involving synchrotron, synchrotron self Compton (SSC) and external Compton (EC) processes. However, the flaring state (60260-60310\,MJD) during which the source showed VHE emission requires an additional component. We show that the inclusion of the photo-meson process can successfully explain this excess $\gamma$-ray emission. Further the estimated parameters, also suggest the source is transparent to VHE gamma-rays against pair production process.
Abstract: 2503.01638
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Title:Plans for a new array of radio antennas for the detection of air showers at the 433m surface-detector array of the Pierre Auger Observatory
View PDF HTML (experimental)Abstract:We present the design and science case for a new array of radio antennas to be located at the Pierre Auger Observatory. Six stations of three SKALA antennas each will be deployed around a single water-Cherenkov surface detector triggering the radio readout. The planned antenna layout will allow for the detection of cosmic rays above a few tens of PeV and reach full efficiency for vertical air showers at several hundred PeV in primary energy. The array will thus be a pathfinder to demonstrate that fully-efficient radio detection in combination with the underground muon detectors already present at the location is possible. This will enable combined studies of the muon component and the depth of shower maximum, relevant for hadronic interaction models studies and more accurate determination of the cosmic-ray mass composition in the energy range of the Galactic-to-extragalactic transition.
Abstract: 2503.01278
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Title:Multi-wavelength study for gamma-ray nova V1405 Cas
View PDF HTML (experimental)Abstract:Novae are found to have GeV to TeV gamma-ray emission, which reveals the shock acceleration from the white dwarfs. Recently, V1405 Cas was reported to radiated suspicious gamma-ray by \textit{Fermi}-LAT with low significance ($4.1 \sigma$) after the optical maximum. Radio observations reveal that it is one of the five brightest novae surrounded by low-density ionized gas columns. Here we report continuous search for GeV gamma-ray from \textit{Fermi}-LAT. No gamma-ray were found. For V1405 Cas, the flux level is lower than other well-studied \textit{Fermi} novae, and the gamma-ray maximum appear at $t_{0} + 145$ d. Gamma-ray of V1405 Cas are used to search potential gamma-ray periodicity. No gamma-ray periodicity was found during the time of observation. By comparing multi-wavelength data, the gamma-ray upper limit to optical flux ratio with value at around $10^{-4}$ is obtained to constrain the shock acceleration. Long-term analysis from \textit{Swift}-XRT gets X-ray spectral in the post-shock phase, which indicates that V1405 Cas became a super-soft source. The best-fit black body temperature at the super soft state is 0.11 - 0.19 keV.
Abstract: 2503.02750
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Title:Quantitative exploration of the similarity of gamma-ray pulsar light curves
View PDF HTML (experimental)Abstract:We introduce and apply a methodology based on dynamic time warping (DTW) to compare the whole set of gamma-ray light curves reported in the Third Fermi-Large Area Telescope Pulsar Catalogue. Our method allows us to quantitatively measure the degree of global similarity between two light curves beyond comparing indicators such as how many peaks there are, which is their separation, width, and height. Once the morphology of the light curve is showcased via background subtraction, min-max scaler normalization, and rotations are considered to take into account that phase 0 is arbitrary, the level of detail with which light curves of different pulsars appear is revealed. In many cases their similarity is striking and occurs disregarding any other timing, physical, or spectral property. In particular, some MSPs and young pulsars share detailed light curve morphology.
Abstract: 2503.03610
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Title:Identifying multiplets of IceCube alert events
View PDF HTML (experimental)Abstract:The IceCube Neutrino Observatory publishes "alert events", i.e. detections of high-energy neutrinos with a moderate-to-high probability of being of astrophysical origin. While some events are produced in the atmosphere, a fraction of alert events should point back to their astrophysical sources. We aim to identify multiple alert events possibly related to a single astrophysical counterpart by searching for spatial and temporal clusterings in 13 years of alert data. We identify spatial clusters ("multiplets") by checking for events overlapping within their uncertainty regions. In order to reduce chance coincidences and to improve the signal purity of our sample, we apply different thresholds. We investigate the weighted mean position of these multiplets for an over-fluctuation of gamma-ray counterparts. As a final step, we apply expectation maximization to search for temporal clusters around the identified weighted mean positions. We find no statistically significant clustering of alert events around a specific origin direction or in time. This could be because the selections are still dominated by atmospheric background. Another possibility is that we are not yet sensitive enough and only detect single events from sources. In this case, we need more data in order to observe a clustering of events around their origin.
Abstract: 2503.03699
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Title:High-Energy Neutrinos by Hydrogen-rich Supernovae interacting with low-massive Circumstellar Medium: The Case of SN 2023ixf
View PDF HTML (experimental)Abstract:In hydrogen-rich (H-rich) Supernova (SN) events, the collision between the H-rich ejecta and the Circum-Stellar Medium (CSM) can accelerate particles and produce high-energy neutrinos (HE-$\nu$, TeV-PeV) through proton-proton inelastic scattering. Despite understanding the production mechanism of these neutrinos, the lack of direct observations raises questions about particle acceleration efficiency and the involved astrophysical conditions. This study focuses on neutrino emission from H-rich SNe with low-mass CSM, such as SN 2023ixf. We developed a semi-analytical model to characterize the progenitor and CSM at the explosion time, allowing us to infer the expected neutrino flux at Earth during the SN's interaction phase. Our model shows that neutrino emission depends not only on shock velocity and CSM mass but also on the spatial matter distribution of the CSM. By analysing the bolometric light curve of SN 2023ixf beyond 100 days post-explosion, we find that its ejecta, consisting of $9\,\text{M}_{\rm \odot}$ (including $0.07\,\text{M}_{\rm \odot}$ of radioactive $^{56}$Ni) and having a kinetic energy of $1.8\,\text{foe}$, collides with a low-mass CSM of $0.06\,\text{M}_{\rm \odot}$ distributed according to a power-law density profile with an exponent of $s=2.9$. Through these parameters, we estimate that up to $4\pm1\times 10^{-2}$ muon (anti-)neutrino events could be detected by IceCube within 50 days post-explosion. Although the predicted flux ($\lesssim 3\times 10^{-9}\,\text{GeV} \, \text{cm}^{-2} \, \text{s}^{-1}$) is below current IceCube sensitivity, future telescopes like IceCube-Gen2 and KM3NeT could detect HE-$\nu$ from similar SN events.
Abstract: 2503.03823
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Title:Bounds on neutrino-DM interactions from TXS 0506+056 neutrino outburst
View PDF HTML (experimental)Abstract:We constrain the neutrino-dark matter cross-section using the $13 \pm 5$ neutrino event excess observed by IceCube in 2014-2015 from the direction of the blazar TXS 0506+056. Our analysis takes advantage of the dark matter overdensity spike surrounding the supermassive black hole at the center of the blazar. In our results, we take into account uncertainties related to the different types of neutrino emission models and the features of the dark matter spike, considering cross-sections that scale with energy as $\sigma \propto (E_{\nu} /E_0)^n$, for values of $n = 1, 0, -1, -2$. In our best-case scenario, we obtain limits competitive with those derived from other active galaxies, tidal disruption events (TDEs), and the IC-170922A event.
Abstract: 2503.04434
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Title:The Firmamento platform
View PDF HTML (experimental)Abstract:This paper introduces Firmamento, a new online platform designed for astronomical research, particularly for studying blazars and other multi-messenger emitters. Firmamento provides access to a wealth of astronomical data, including imaging, spectral, and timing information, along with tools for data analysis and machine learning. A key feature is the Error Region Counterpart Identifier (ERCI), which helps locate potential counterparts to gamma-ray and other high-energy sources pinpointing objects exhibiting blazar-like characteristics. Firmamento grants access to spectral data across the entire electromagnetic spectrum, offering well-populated SED generation and VHE detectability estimation. The platform also supports user-provided data, allowing researchers to incorporate their own source lists.
Abstract: 2503.04464
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Title:Super heavy dark matter origin of the PeV neutrino event: KM3-230213A
View PDF HTML (experimental)Abstract:The recent observation of the ultra-high-energy neutrino event KM3-230213A by the KM3NeT experiment offers a compelling avenue to explore physics beyond the Standard Model. In this work, we explore a simplest possibility that this event originates from the decay of a super-heavy dark matter (SHDM). We consider a minimal extension of the type-I seesaw by including a singlet scalar and a singlet fermion DM, both being odd under a $Z_2$ symmetry. At high scale, the $Z_2$ symmetry is spontaneously broken by the vev of the $Z_2$ odd scalar, leading to i) mixing between DM and heavy right-handed neutrinos and ii) formation of domain walls (DW). In the former case, the decay of the DM to $\nu,h$ can give rise to the PeV neutrino event KM3-230213A. While, in the latter case, the disappearance of the DW can give rise to stochastic gravitational waves. We derive constraints on the DM lifetime as a function of DM mass ensuring consistency with IceCube, Auger upper limits and the observed KM3-230213A event. We found that KM3-230213A gives stringent constraint on DM mass ranging from $1.7\times10^8$ GeV to $5.5\times10^9$ GeV with lifetime $6.3\times10^{29}$ s to $3.6\times10^{29}$ s.
Abstract: 2503.04632
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Title:Impact of multi-messenger spectral modelling on blazar-neutrino associations
View PDF HTML (experimental)Abstract:Blazars are interesting source candidates for astrophysical neutrino emission. Multi-messenger lepto-hadronic models based on proton-photon (p-gamma) interactions result in predictions for the neutrino spectra which are typically strongly peaked at high energies. In contrast, statistical analyses looking to associate blazars and neutrinos often assume a power-law spectral shape, putting the emphasis at lower energies. We aim to examine the impact of such spectral modelling assumptions on the associations of neutrinos with blazars. We use hierarchical_nu, a Bayesian framework for point source searches, and incorporate the theoretical predictions for neutrino spectra through a dedicated spectral model and priors on the relevant parameters. Our spectral model is based on the predictions presented in Rodrigues et al. (2024) for a selection of intermediate and high synchrotron peaked blazars that have been connected with IceCube neutrino alert events. We apply our model to the 10 years of publicly available IceCube data, focusing on the Northern hemisphere. Out of 29 source candidates, we find five sources, including TXS 0506+056, that have an association probability greater than 0.5 to at least one event. The p-gamma spectra typically lead to a lower overall number of associated events compared to the power-law case, but retain or even enhance strong associations to high-energy events. Our results demonstrate that including more information from theoretical predictions can allow for more interpretable source-neutrino connections.
Abstract: 2503.05100
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Title:Search for spatial coincidence between magnetars and IceCube detected neutrinos
View PDF HTML (experimental)Abstract:We carry out a search for spatial coincidence between high energy neutrinos detected by the IceCube neutrino detector (using the publicly available 10-year muon track data) and 33 magnetars, including two extragalactic ones. We use the unbinned maximum likelihood method for our analysis. We do not find any such spatial association between any of the galactic magnetars and IceCube-detected neutrinos. Therefore, we conclude that none of the known galactic or extragalactic magnetars contribute to the diffuse neutrino flux observed in IceCube.
This page created: Tue Mar 11 14:13:33 ACDT 2025 by Teddy
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