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KM3NeT blog posts

Three new KM3NeT papers

Recently, three KM3NeT papers were accepted by peer-reviewed scientific journals and came on line.

Note, that KM3NeT has an open science policy which means that all papers can be read open access, i.e. without a paywall.

 

1. Following up gravitational wave events – a scientific paper. In the paper ‘Searches for neutrino counterparts of gravitational wavesfrom the LIGO/Virgo third observing run with KM3NeT‘ we report the results of a neutrino follow-up study of gravitational wave sources detected by the LIGO-Virgo interferometers in 2019–2020.

The search focuses both on MeV neutrinos and high-energy neutrinos. No significant excess was observed for any of the sources. Upper limits on the neutrino emission from individual sources and the typical emission from binary black hole mergers were computed and compared with the constraints from other neutrino telescopes.

JCAP04(2024)026, DOI: 10.1088/1475-7516/2024/04/026

In the picture upper limits on the total neutrino fluence for both analyses in comparison with the results of other observatories.

 

2. Differential Sensitivity of ARCA – a scientific paper. In the paper titled ‘Differential Sensitivity of the KM3NeT/ARCA Detector to a Diffuse Neutrino Flux and to Point-like Source Emission: Exploring the Case of Starburst Galaxies‘, for the first time, KM3NeT presents the expected differential sensitivity of the full ARCA detector for both diffuse and point-like neutrino fluxes.

In particular, this study is applied to Starburst Galaxies, demonstrating that the ARCA detector, when completed, can trace TeV neutrinos from these sources. For instance, with ARCA it will be possible to discriminate between different astrophysical components in NGC 1068 after 3 years of data taking, strengthening the observations of the IceCube Neutrino Observatory.

In the pictures: (left) the sensitivities of the ARCA detector after 10 years of operation as a function of neutrino energy, compared to measurements of the IceCube neutrino observatory; (right) the discovery neutrino flux as a function of operation time.

Astroparticle Physics, Volume 162, DOI: 10.1016/j.astropartphys.2024.102990

 

3. Powering optical modules – a technical paper. The optical modules in the KM3NeT neutrino telescope in the deep Mediterranean Sea receive electrical power from the control station on the shore. An electronics board – dubbed the Power Board – in each optical module is described in the paper ‘The Power Board of the KM3NeT Digital Optical Module: design, upgrade, and production’. The board arranges powering individual components in the module at different voltage levels. The Power Board has been subjected to rigorous test to ensure reliable operation in the deep sea for more than a decade.

In the picture a photo of the Power Board with the various DC/DC converters generating the voltages needed.

Electronics 2024,13(11), 2044, DOI: 10.3390/electronics13112044

 

In addition, three new pre-prints were stored on the arXiv and submitted to the relevant scientific journals for peer-review:

  • Astronomy potential of KM3NeT/ARCA, arXiv:2402.08363, submitted to EPJ-C

  • Atmospheric muons measured with the KM3NeT detectors in comparison with updated numeric predictions, arXiv: 2403.11946, submitted to EPJ-C

  • Search for Neutrino Emission from GRB 221009A using the KM3NeT ARCA and ORCA detectors, arXiv: 2404.05354, submitted to JCAP

We will report on these once they are accepted for print by the journals.

An exciting Collaboration meeting in Bologna

5 March 2024 – The KM3NeT Collaboration met again, in Bologna and online, in February.

With so many data analyses ongoing, the meeting gave the opportunity to discuss a harvest of new results. As plans are being prepared for next massive sea campaigns to be performed for ARCA and ORCA this year, there was a lot to discuss also on the construction side.

During the meeting the recipients of the Giorgos Androulakis Prize, Agustín Sánchez Losa and Riccardo Bruno, were announced.

An application by UCLouvain to upgrade their membership from observer to full member was endorsed. Drexel University (Philadephia, US) and the University of Würzburg (Germany) were welcomed as observers, with the PIs Naoko Kurahashi Neilson and Sara Buson, respectively. Cássius Anderson Miquele de Melo from the Universidade Federal de Alfenas, Brasil joined as a new Associated Member. Welcome to all of you!

We also had some cheerful activities, with several colleagues participating in social games that lasted the full week. That was also an opportunity to meet new people from different institutes.

It was great to discuss of frontier science at the oldest University in Europe – many thanks to the local team for a superb organization!

The next Collaboration meeting will be in June in Texel, in the Netherlands.

 

Agustín Sánchez Losa and Riccardo Bruno awarded the Giorgos Androulakis Prize

5 March 2024 – During the recent KM3NeT collaboration meeting, in Bologna last month, the awardees of the second edition of the Giorgos Androulakis Prize were announced.

With the prize, KM3NeT recognises “exceptional contribution to the KM3NeT project that has a particularly high impact on the success or progress of KM3NeT”.

The prize is named after Giorgos Androulakis, the late KM3NeT Quality Manager, in order to commemorate Giorgos’ dedication to the project. The prize is awarded in two categories: Early-Career Scientists and Technicians & Engineers.

The winners of the second edition of the KM3NeT Giorgos Androulakis Prize are:

  • in the category Early Career Scientists: Agustín Sánchez Losa of IFIC, “for his long-standing, diverse and essential contributions to the KM3NeT detector calibration“
  • in the category Technicians and Engineers: Riccardo Bruno of INFN Catania, “for his dedicated, leading and vital contributions to the KM3NeT project, in particular in: setting up the software tool for functional and acceptance tests for WWRS DOMs; developing the White Rabbit system; construction of the WWRS DOM prototypes; his support of the integration teams producing WWRS DOMs“

Congratulations to Agustín and Riccardo! With many thanks for your dedication to KM3NeT.

The winners of the Giorgos Androulakis Prize, Agustín Sánchez Losa (left) and Riccardo Bruno (right), receiving the prize from the KM3NeT spokesperson, Paschal Coyle

Paper alert

20 November 2023 – Recently, KM3NeT published on the arXiv pre-prints of two new papers:

1 – Embedded software of the KM3NeT Central Logic Board

This KM3NeT technical paper describes the embedded software running in the data acquisition of the telescope. Located in the deep Mediterranean Sea, the hardware of the telescope is not directly accessible. The implemented software facilitates remote management of the deployed hardware and safe reconfiguration of firmware. It runs on the central electronics board of each optical module of the KM3NeT detectors. The central logic board coordinates the readout of all equipment inside the module and manages the communication and data transmission over optical fibers connecting the module to the control station on shore.

Read the details at arXiv.2308.01032

(Accepted for publication in Computer Physics Communications)

 

2 – KM3NeT neutrino follow-up of gravitational wave sources

In this paper the KM3NeT Collaboration reports the results of a neutrino follow-up study made with ORCA data of gravitational wave sources detected by LIGO–Virgo in 2019-2020. The search focuses both on MeV neutrinos and high-energy neutrinos. No significant excess was observed for any of the sources.

Upper limits on the neutrino emission from individual sources and the typical emission from binary black hole mergers are computed and compared with the constraints from other neutrino telescopes.

Since May 2023, the Collaboration is performing real-time follow-ups of the GW triggers detected by LIGO-Virgo-KAGRA in their fourth observing run, with both ORCA and ARCA detectors with much larger instrumented volumes than in the previous searches.

In the figure the comparison of 90% upper limits on the neutrino fluence from gravitational wave sources for ANTARES, IceCube, Super-Kamiokande and KM3NeT.

 

Read the details at arXiv.2311.03804

The paper has been submitted for publication after peer-review.

 

KM3NeT/ARCA enlarged to 28 Detection Units

10 October 2023 – An important two-week marine operation has been successfully carried out at the KM3NeT ARCA site, offshore Capo Passero, Sicily in September.

The campaign was performed with the Optimus Prime, equipped with a FUGRO underwater vehicle (ROV). The ship set sail from Malta on Monday, 11 September and came back to the port at the end of the operation on Thursday, 23 September.

The operation was among the last activities of PACK, a project supported by MUR (the Italian Ministry of University and Research) for the period 2019-2023, aimed at enlarging the deep-sea telescope and at enhancing the KM3NeT facilities in Bari, Caserta and Naples.

Soon after completing the operation, the commissioning of the enlarged ARCA telescope was started.

ARCA now comprises 28 detection units, which are altogether equipped with 504 Digital Optical Modules, with a total of more than 15,000 photomultipliers.

Deployment of a detection unit from Optimus Prime
The start of the unfurling of a detection unit as seen from the ROV control room onboard the Optimus Prime.
Tests of a newly deployed detection unit from the shore station in Portopalo di Capo Passero

KM3NeT in the ICRC2023 proceedings

The ICRC is the International Cosmic Ray Conference. It is one of the major conferences in astroparticle physics and covers many subfields. In 2023, the 38th International Cosmic Ray Conference (ICRC) took place in Nagoya, Japan.

KM3NeT researchers actively participated to present the work of the Collaboration and many contributions to the proceedings of the conference were published. The full proceedings of ICRC2023 can be found at here. Below you find the individual KM3NeT contributions, categorised in the various scientific and technological fields.

Neutrino astronomy using the KM3NeT/ARCA detector

Solar and heliospheric physics

Multi-messenger and gravitational waves

Neutrino oscillation physics using the KM3NeT/ORCA detector

Charged cosmic ray physics

Dark matter and exotics

Calibration

Data acquisition

Reconstruction and analysis tools

Outreach

 

KM3NeT presented at conferences worldwide

15 September 2023 – This summer, KM3NeT members participated in conferences all over the world to present the latest results and  developments of our Collaboration.

Besides TAUP in Vienna, EPS-HEP in Hamburg, and TeVPA in Naples, KM3NeT-ers have massively attended the 38th International Cosmic Ray Conference (ICRC), in Nagoya, Japan. Since the ICRC is among the largest conferences in the field of astroparticle physics, it was an ideal opportunity for reporting the progress of the collaboration in neutrino astronomy, neutrino physics, multi-messenger astronomy, cosmic rays, and dark matter searches.

In total, KM3NeT presented 10 talks and 28 posters at the ICRC, in addition to a plenary talk given by prof. Antoine Kouchner, the spokesperson of the ANTARES Collaboration, on catching neutrinos in the Mediterranean Sea.

Interested?

The full proceedings of ICRC2023 can be found here. For your convenience, the contributions of KM3NeT to the proceedings are available here and are also on arXiv: https://arxiv.org/abs/2309.05016.

KM3NeT members at the ICRC2023.
Antoine Kouchner, spokesperson of the ANTARES Collaboration, presenting at the ICRC2023 an overview of recent work achieved by ANTARES and KM3NeT.
Some of the talks given by KM3NeT members at the ICRC2023.
Some of the posters presented by KM3NeT members at the ICRC2023.

 

Neutrino emission from our Galaxy! New observations by the IceCube Collaboration

29 June 2023 – The KM3NeT Collaboration congratulates the IceCube Collaboration after today’s announcement of an evidence in IceCube of high-energy neutrinos originating from our own Galaxy.

“Congratulations to the IceCube Collaboration for this great result. For the KM3NeT Collaboration it is a very important observation” says Paschal Coyle, the KM3NeT Spokesperson.

While IceCube has previously reported evidence for several sources of extragalactic neutrinos, the detection of neutrinos from the Milky Way has proved difficult,  due to the IceCube’s location at the South Pole, where a signal from within our Galaxy is observed as downgoing events and is therefore subject to a large background of atmospheric muons. Furthermore, as the signal was observed in the cascade channel, which has a limited angular resolution, it was not possible to determine if the signal is due to a diffuse source or a collection of unresolved point sources.

A telescope located in the Northern hemisphere, such as KM3NeT, observes our Galaxy using upgoing events, which have significantly less background than downgoing events and are therefore easier to detect. This in fact allowed ANTARES to report the first hint of a neutrino emission from the Galaxy (see the news item on the ANTARES web-site).

Moreover, the KM3NeT telescope will be able to observe the signal in the muon neutrino channel in addition to the electron neutrino channel and both with a much better angular resolution than IceCube.

“IceCube has confirmed our Galaxy is a guaranteed source of high-energy neutrinos. KM3NeT looks forward to unravelling the origins of this Galactic signal with unprecedented precision” concludes Paschal Coyle.

A cheerful Collaboration meeting in Salerno

14 June 2023 – The KM3NeT Collaboration met in Salerno last week.

It was quite a busy week, during which the status of data taking and data analysis of ARCA and ORCA as well as the contributions to the ICRC 2023 were reviewed, the progress in detector construction was discussed (celebrating the remarkable result of the 1,100th built DOM!) and the plans for next sea campaigns were refined.

The Collaboration continues to grow, with a research team joining as observer from Institute of Experimental Physics in Kosice, Slovakia (team leader: Blahoslav Pastircak).

Many thanks to the organizing team in Salerno!

The next Collaboration meeting will be in October in Paris and will include a day dedicated to celebrating the success of ANTARES, the first-undersea neutrino telescope ever built, progenitor of KM3NeT.

Three more detection units for KM3NeT/ORCA

1 May 2023 – During a two days sea operation, 27-28 April 2023, three detection units were successfully connected to the ORCA detector of KM3NeT in a record time of just over 24 hours. In addition, an acoustic beacon was recovered for battery replacement. The total number of deployed ORCA units is now 18, as visible in the sonar scan above.

As usual, the operation was performed with two ships: the Castor of Foselev, for deployment of the detection units, and the Janus II of SAAS (formerly Comex), equipped with a deep-sea remotely operated vehicle, for submarine operations.

Many thanks to the crews offshore as well as to the team who performed the functional tests of the new detection units from the shore station!