Publications associées à Sursaut gamma

Mountaintop Gamma Ray Observations of Three Terrestrial Gamma‐Ray Flashes at the Säntis Tower, Switzerland With Coincident Radio Waveforms

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri, Amirhossein Mostajabi

We report on the mountain top observation of three terrestrial gamma-ray flashes (TGFs) that occurred during the summer storm season of 2021. To our knowledge, these are the first TGFs observed in a mountaintop environment and the first published European ...

2024

Constraints on the intergalactic magnetic field from Fermi/LAT observations of the 'pair echo' of GRB 221009A

Andrii Neronov

Delayed 'pair-echo' signal from interactions of very-high-energy gamma rays in the intergalactic medium can be used for the detection of the intergalactic magnetic field (IGMF). We used the data of the Fermi/LAT telescope coupled with LHAASO observatory me ...

Edp Sciences S A2024

COSMOS-Web: Intrinsically Luminous z ≳ 10 Galaxy Candidates Test Early Stellar Mass Assembly

Michaela Hirschmann

We report the discovery of 15 exceptionally luminous 10 less than or similar to z less than or similar to 14 candidate galaxies discovered in the first 0.28 deg(2) of JWST/NIRCam imaging from the COSMOS-Web survey. These sources span rest-frame UV magnitud ...

Iop Publishing Ltd2024

VolRecon: Volume Rendering of Signed Ray Distance Functions for Generalizable Multi-View Reconstruction

Sabine Süsstrunk, Yufan Ren, Tong Zhang

The success of the Neural Radiance Fields (NeRF) in novel view synthesis has inspired researchers to propose neural implicit scene reconstruction. However, most existing neural implicit reconstruction methods optimize perscene parameters and therefore lack ...

2024

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part II-Analysis Based on Frequency Domain Electromagnetic Radiation

Farhad Rachidi-Haeri, Marcos Rubinstein

In Part I of this paper, an inequality satisfied by the vacuum energy density of the universe was derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to ...

2024

Measurement of the K+ → π+γγ decay

Alessandro Mapelli, Radoslav Marchevski, Alina Kleimenova

A sample of 3984 candidates of the K+ -> pi(+)gamma gamma decay, with an estimated background of 291 +/- 14 events, was collected by the NA62 experiment at CERN during 2017-2018. In order to describe the observed di-photon mass spectrum, the next-to-leadin ...

Elsevier2024

GHOST commissioning science results - II: a very metal-poor star witnessing the early galactic assembly

Pascale Jablonka

This study focuses on Pristine_180956.78-294759.8 (hereafter P180956, [Fe/H] = -1.95 +/- 0.02), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up with the recently commissioned Gemini High-resolution Optical SpecTrograph (GHOST) ...

Oxford Univ Press2024

Hadronic nature of high-energy emission from the Galactic ridge

Andrii Neronov

We show that the IceCube observation of the Galactic neutrino-flux component confirms the hint of detection of neutrinos from the Galactic ridge (the inner part of the Milky Way disk within the Galactic longitude IlI < 30(degrees)), previously reported by ...

American Physical Society2023

Attaining the PeV frontier of the cosmic ray spectrum in space with HERD

Chiara Perrina

The High Energy cosmic-Radiation Detection facility (HERD) is a calorimetric experiment planned to be launched in 2027. It will be operational for at least 10 years on board the China Space Station. With HERD we will measure the energy flux of cosmic proto ...

E D P SCIENCES2023

Gamma-Blind Fast Neutron Detection for Spent Nuclear Fuel Characterization

Alexander Wolfertz

In this thesis, the development and testing of a system for measuring the axial distribution of fast neutron emission of spent nuclear fuel rods is presented. Emphasis is placed on the novel fast neutron detector used which can reliably work in extremely h ...

EPFL2023

Power variations in fractional Sobolev spaces for a class of parabolic stochastic PDEs

Robert Dalang, Carsten Hao Ye Chong

We consider a class of parabolic stochastic PDEs on bounded domains D c Rd that includes the stochastic heat equation but with a fractional power gamma of the Laplacian. Viewing the solution as a process with values in a scale of fractional Sobolev spaces ...

INT STATISTICAL INST2023

Revealing galaxy candidates out to z similar to 16 with JWST observations of the lensing cluster SMACS0723

Jean-Paul Richard Kneib, Hakim Atek, Johan Richard

One of the main goals of the JWST is to study the first galaxies in the Universe. We present a systematic photometric analysis of very distant galaxies in the first JWST deep field towards the massive lensing cluster SMACS0723. As a result, we report the d ...

OXFORD UNIV PRESS2023

The formation of the faintest galaxies in cosmological simulations: from the impact of primordial magnetic fields to the metal enrichment of present day dwarfs by first stars

Mahsa Sanati

In the theory of the bottom-up assembly of cosmic structures, one of the main challenges is to connect the smallest, most inconspicuous galaxies we observe today to the building blocks of more massive galaxies such as our own, the Milky Way. Do these so-ca ...

EPFL2023

Performance of the Quasar Spectral Templates for the Dark Energy Spectroscopic Instrument

Jiaxi Yu, Zheng Zheng

Millions of quasar spectra will be collected by the Dark Energy Spectroscopic Instrument (DESI), leading to a fourfold increase in the number of known quasars. High-accuracy quasar classification is essential to tighten constraints on cosmological paramete ...

IOP Publishing Ltd2023

DARKFLUX: A new tool to analyze indirect-detection spectra of next-generation dark matter models

Emma Elizabeth Tolley

We present DARKFLUX, a software tool designed to analyze indirect-detection signatures for next-generation models of dark matter (DM) with multiple annihilation channels. Version 1.0 of this tool accepts user-generated models with 2 -> 2 tree-level dark ma ...

ELSEVIER2022

Beware of beam damage under reaction conditions: X-ray induced photochemical reduction of supported VOx catalysts during in situ XAS experiments

Oliver Kröcher, Davide Ferri, Anna Zabilska, Olga Safonova

In situ X-ray absorption spectroscopy (XAS) is a powerful technique for the investigation of heterogeneous catalysts and electrocatalysts. The obtained XAS spectra are usually interpreted from the point of view of the investigated chemical processes, there ...

ROYAL SOC CHEMISTRY2022

Detectability of Large Correlation Length Inflationary Magnetic Field with Cherenkov Telescopes

Andrii Neronov

Magnetic fields occupying the voids of the large scale structure may be a relic from the Early Universe originating from either Inflation or from cosmological phase transitions. We explore the possibility of identifying the inflationary origin of the void ...

2022

Dynamics of cavitation bubbles near granular boundaries

Mohamed Farhat, Davide Bernardo Preso, Armand Baptiste Sieber

We study the dynamics of a cavitation bubble near beds of sand of different grain sizes. We use high-speed imaging to observe the motion of the bubble and the sand for different values of the stand-off parameter gamma (dimensionless bubble-boundary distanc ...

Cambridge University Press2022

Euclid: Searching for pair-instability supernovae with the Deep Survey

Frédéric Courbin, Georges Meylan, Giovanni Longo, Yi Wang, Richard Massey

Pair-instability supernovae are theorized supernovae that have not yet been observationally confirmed. They are predicted to exist in low-metallicity environments. Because overall metallicity becomes lower at higher redshifts, deep near-infrared transient ...

EDP SCIENCES S A2022

Signatures of anisotropic diffusion around PeVatrons in 100 TeV gamma-ray data

Andrii Neronov

The Tibet AS gamma collaboration has reported a diffuse gamma-ray emission signal from the Galactic Plane. We consider the possibility that the diffuse emission from the outer Galactic Plane at the highest energies is produced by cosmic rays spreading from ...

American Physical Society2022