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A key objective of the AHEAD 2020 networking activities for the synergies between the Gravitational Wave and High Energy Astrophysics communities is to organize an European scientific network including geoscience observatories.
This workshop is the final of a series of events organized in the years 2020, 2021 and 2022 to discuss the roadmap of the convergence and the preparation of the future steps.
There is no fee for participation. The workshop will be held in hybrid format, with participation in presence at the European Gravitational Observatory and remote connection with Zoom.
Scientific Organizing Committee: Francesca Badaracco, Marica Branchesi, Massimo Carpinelli, Elena Cuoco, Irene Fiori, Jan Harms, Michele Punturo.
ZOOM Coordinates: ZOOM link, meeting ID and Passcode will be shared only with registered participants by e-mail.
Among astrophysical gravitational waves sources yet undetected, of great interest are the binary close encounters involving black holes and/or neutron stars. These systems are characterized by high orbital eccentricities and form via dynamical interactions in dense stellar environments, like globular clusters or Active Galactic Nuclei disks. Their detection could shed light on the different formation channels and could allow tests of General Relativity in the strong field regime as well as multimessenger observations.
The expected gravitational wave emission from these events differs from standard coalescences, being instead characterized by repeated short duration bursts emitted at each periastron passage of the two objects. The burst nature of the signal paired with the expected low signal-to-noise ratio makes them a challenging source either for detection or parameter estimation with traditional data analysis approaches. We present HYPERION (“HYP-er fast close EncounteR Inference from Observation with Normalizing-flows”): a novel data analysis pipeline based on probabilistic machine learning and normalizing flows to infer Bayesian posterior. We show that our method is very promising, since it can make detection and inference several orders of magnitude faster than traditional techniques while maintaining high accuracy on the parameters, thus showing how machine learning could help in studying these sources.
Astroparticles can get trapped in the Earth’s magnetosphere. There are a number of measurements of protons, electrons, heavy ions, solar energetic protons, galactic cosmic rays, as well as positrons in near-Earth space. The high-energy electrons in the Earth’s radiation belts were discovered by the first US satellite Explorer-1, which was designed to study cosmic rays. In the proposed project, we will explore measurements of heliophysical particles in space using data from different satellite missions and develop machine learning-based models to monitor and now-cast the high-energy particle environment. Astrophysical particles can also cause chains of particle generation. Precipitation of energetic particles from space can generate nitric oxide in the atmosphere, and nitric oxide destroys ozone very efficiently. Geomagnetic activity that controls the precipitation of magnetospheric particles is now recommended as part of the solar forcing of the climate system for model experiments. However, it is not clear which particles and at which energies play the largest role. The complication of estimating the effect of the precipitating particles usually arises from the fact that measurements are sparse and the global models of the precipitating particle environment are not available. In this project, we will utilize a range of measurements and models to develop maps of the precipitating particle environment and study how atmospheric parameters can be correlated with our predictive maps of precipitation. In this presentation, we will show our model results for the precipitating electrons from the magnetosphere to the atmosphere.
KM3NeT is an underwater Cherenkov neutrino telescope operating in the abysses of the Mediterranean Sea. It consists of two detectors: one located at 2500m water depth, 40 km offshore South of Toulon (France), in the Ligurian Sea; the other one located at 3500m depth, 90 km offshore South East of Capo Passero (Sicily) in the Ionian Sea.
Each detector is an array of hundreds of mooring lines (detection units, DU), consisting of 18 digital optical modules. Each optical module host 31 3’’PMTs. DUs are powered and connected to shore by a network of electro-optical cables and junction boxes converging into a main electro-optical cable.
Each optical module hosts a piezoelectric acoustic sensor and a compass, each DU base is equipped with a hydrophone. The detector is complemented by special mooring lines, equipped with oceanographic sensors. Junction boxes provide connection to seabed observatories and instruments for geoscience.
We will report on successful use of KM3NeT sensors and marine infrastructures for innovative studies on oceanography, biology, and geophysics.
There are still several unanswered fundamental questions concerning our planet and in particular, about the deep Earth, from where we lack direct samples. Geo-neutrinos, electron anti-neutrinos produced in β decays of naturally occurring radioactive isotopes in the Earth, are a unique direct probe of our planet’s interior. If detected, they allow to quantify the amount and distribution of radiogenic elements and to constrain the energy balance. Progress in neutrino-detection techniques has made their study possible: ultrapure large underground liquid scintillators are particularly suited to measure antineutrino fluxes. The geoneutrino signal has been robustly detected by the Borexino and KamLAND Collaborations and consequences for Earth’s radiogenic deduced. The talk is aimed to summarize the present status and the future perspectives in the field.
In order to detect gravitational waves, Virgo measures extremely small variations in differential elongations of the arms. Sources of geophysical and anthropogenic environmental noises, such as wind and railway traffic, can impact on the detector causing transient sensitivity worsening and gaps in data taking. We review the major sources studied during the last observing run and the more recent commissioning period, illustrating their characteristics and the observed impact on the Virgo detector.
The LabEx Univ'EarthS is a research program founded in 2011 that combines the scientific and technical expertise of several laboratories of Université Paris Cité (AIM, APC, IPGP, ONERA) to enhance the development of interdisciplinary projects and outreach initiatives in the fields of Earth and Universe Sciences. Over its >10 years of existence, it has funded about 50 projects involving more than 500 staff members in the participating laboratories. This contribution will provide an overview of some of the salient projects and outreach conducted by the LabEx, as an illustration of its crucial role to support the development of a scientific community at the geo-astro interface.
Eötvös balance is a dipole type gradio-gravitometer. In recent years, simple innovations have increased its sensitivity by two orders of magnitude, making it more sensitive to environmental effects, like pressure changes, Earth-mantle deformation, or earthquake-related events, among others [1]. In this presentation we will show the main elements of the modernisation and show examples of some measured geophysical phenomena, as well as our efforts to measure Newtonian noise.
[1] https://arxiv.org/abs/2202.09607
We highlight recent results from geophysical researches and applications conducted via measuring cosmic muons by HUN-REN Wigner RCP and University of Tokyo. Our main infrastructure is the Sakurajima Muography Observatory in Kyushu, Japan. It is a modular system that is operating with muon trackers based on gaseous detectors and scintillators. The SMO is monitoring the mass density changes through the upper plumbing system of the volcanic edifice and in the atmosphere by means of muography [1,2]. Mass changes has been observed on the surface regions of the volcanic edifice due to deposition and erosion of volcanic ejecta and by post-eruptive lahars. The evolution of magmatic plug has been observed beneath the active craters that helped to explain the link between eruption frequency and ground deformation. An inverse correlation has been observed between the mass density changes beneath two adjacent craters that suggests a branched conduit structure. Besides volcanic phenomena, the SMO captured atmospheric pressure drops caused by tropical cyclones and monitored the passages of different cyclones near Kagoshima. Besides geophysical research, we will present various applications from cosmic background measurements in underground laboratories to muographic surveying of infrastructures (dams, pillars, tunnels). Future prospects of muography in geophysical research will also be discussed.
[1] Oláh, L., Tanaka, H.K.M., Varga, D. Muography: Exploring Earth Subsurface with Elementary Particles Geophys. Mon. Ser. 270 (2022). https://doi.org/10.1002/9781119722748
[2] Tanaka, H.K.M., Oláh, L., Varga, D. et al. Muography. Nat Rev Methods Primers 3, 88 (2023). https://doi.org/10.1038/s43586-023-00270-7
Soil and rocks are not so elastic as expected, both present damped and delayed mechanical behavior, called viscoelasticity or rheology. Deviation of static and dynamic elasticity moduli of rocks can also be explained via rheology, furthemore, long term measurements prove that motion of the soil around underground facilities may be relevant even years after the construction. Although elastic waves are dispersion and attenuation free, wave propagation in viscoelastic media is dispersive due to the internal dissipation of the media. This behavior detunes the wave propagation velocities and showing futher dissipative and dispersive effects, thus modifying the shape of the wave signal and reduces the amplitude, which may affect the filtering and mitigation of Newtonian noise.
In the talk we present a thermodynamically consistent family of rheological models called Kluitenberg–Verhás model, which covers Hooke’s elasticity, Kelvin–Voigt, Maxwell, Poynting–Thomson–Zener and other models as special cases. Mathematical properties, dispersion relations, wave propagation velocities and attenuation of some models are analyzed. We demonstrate a self-developed symplectic-like staggered grid finite difference method, via reliable simulations of elastic as well as rheological wave propagation problems can be realized both in one and more spatial dimensions. Thanks to the simplicity of the scheme, numerical originated dispersion and dissipation errors can be eliminated, furthermore, the method numerically also preserves total energy. Finally, we briefly review some uniquely developed experimental methods for determining the rheological parameters.
A movable array of environmental sensors is intended for the feed-forward cancellation of the Newtonian noise generated by atmospheric density fluctuations and seismic displacements at the Virgo gravitational wave detector site, with the prospect of being used at the sites of future 3rd generation detectors.
Each robot unit is equipped with a seismic sensor - optionally also a microphone and a magnetometer - for low-noise and low-frequency observations. The robots need to move autonomously in the experimental areas indoors, avoiding obstacles to reach the assigned positions where they start the data acquisition process. Then, the data will be transferred wirelessly to the control software that elaborates them and imparts to all robots the command to move to new optimal positions. Essential requirements of the system are accuracy in positioning and timing.