3 research outputs found
H.E.S.S. realtime follow-ups of IceCube high-energy neutrino alerts
The evidence for multi-messenger photon and neutrino emission from the blazar
TXS 0506+056 has demonstrated the importance of realtime follow-up of neutrino
events by various ground- and space-based facilities. The effort of H.E.S.S.
and other experiments in coordinating observations to obtain quasi-simultaneous
multiwavelength flux and spectrum measurements has been critical in measuring
the chance coincidence with the high-energy neutrino event IC-170922A and
constraining theoretical models. For about a decade, the H.E.S.S. transient
program has included a search for gamma-ray emission associated with
high-energy neutrino alerts, looking for gamma-ray activity from known sources
and newly detected emitters consistent with the neutrino location. In this
contribution, we present an overview of follow-up activities for realtime
neutrino alerts with H.E.S.S. in 2021 and 2022. Our analysis includes both
public IceCube neutrino alerts and alerts exchanged as part of a joint
H.E.S.S.-IceCube program. We focus on interesting coincidences observed with
gamma-ray sources, particularly highlighting the significant detection of PKS
0625-35, an AGN previously detected by H.E.S.S., and three IceCube neutrinos.Comment: Presented at the 38th International Cosmic Ray Conference (ICRC2023).
See arXiv:2307.13047 for all IceCube contribution
H.E.S.S. realtime follow-ups of IceCube high-energy neutrino alerts
International audienceThe evidence for multi-messenger photon and neutrino emission from the blazar TXS 0506+056 has demonstrated the importance of realtime follow-up of neutrino events by various ground- and space-based facilities. The effort of H.E.S.S. and other experiments in coordinating observations to obtain quasi-simultaneous multiwavelength flux and spectrum measurements has been critical in measuring the chance coincidence with the high-energy neutrino event IC-170922A and constraining theoretical models. For about a decade, the H.E.S.S. transient program has included a search for gamma-ray emission associated with high-energy neutrino alerts, looking for gamma-ray activity from known sources and newly detected emitters consistent with the neutrino location. In this contribution, we present an overview of follow-up activities for realtime neutrino alerts with H.E.S.S. in 2021 and 2022. Our analysis includes both public IceCube neutrino alerts and alerts exchanged as part of a joint H.E.S.S.--IceCube program. We focus on interesting coincidences observed with gamma-ray sources, particularly highlighting the significant detection of PKS 0625-35, an AGN previously detected by H.E.S.S., and three IceCube neutrinos
The Power Board of the KM3NeT Digital Optical Module: Design, Upgrade, and Production
The KM3NeT Collaboration is building an underwater neutrino observatory at the bottom of
the Mediterranean Sea, consisting of two neutrino telescopes, both composed of a three-dimensional
array of light detectors, known as digital optical modules. Each digital optical module contains a
set of 31 three-inch photomultiplier tubes distributed over the surface of a 0.44 m diameter pressure-
resistant glass sphere. The module also includes calibration instruments and electronics for power,
readout, and data acquisition. The power board was developed to supply power to all the elements
of the digital optical module. The design of the power board began in 2013, and ten prototypes
were produced and tested. After an exhaustive validation process in various laboratories within the
KM3NeT Collaboration, a mass production batch began, resulting in the construction of over 1200
power boards so far. These boards were integrated in the digital optical modules that have already
been produced and deployed, which total 828 as of October 2023. In 2017, an upgrade of the power
board, to increase reliability and efficiency, was initiated. The validation of a pre-production series
has been completed, and a production batch of 800 upgraded boards is currently underway. This
paper describes the design, architecture, upgrade, validation, and production of the power board,
including the reliability studies and tests conducted to ensure safe operation at the bottom of the
Mediterranean Sea throughout the observatory’s lifespan