Gravitational waves, predicted over a century ago by Einstein’s theory of General Relativity, have become a powerful observational tool for probing the Universe. I will briefly introduce the physical nature of gravitational waves and the interferometric methods used to detect them. I shall present the scientific results from the recently completed fourth observation run of the LIGO, Virgo, and...
Building on the successful four-year operation of the first instrumented baffle installed on the Input Mode Cleaner (IMC) mirror of Virgo in 2021, IFAE has developed two new large instrumented baffles for deployment in the main arms of the detector. Each baffle, approximately 80 cm in diameter and equipped with 120 photosensors, will be installed at the entrance of the input mirror towers. The...
The next generation of interferometric gravitational wave detectors faces limitations due to excessive thermal noise in key optical and suspension systems, particularly below 10 Hz. To address this issue, cryogenic solutions are being adopted. Dedicated studies are focusing on the creation of cryogenic payloads with quasi-monolithic suspensions, identifying suitable materials for substrates,...
Crystalline Silicon cooled to cryogenic temperatures is a promising material for next-generation gravitational-wave detector optics. Crystalline Silicon has low mechanical loss, so it enables low thermal noise at low temperatures, and it also has two points of zero thermal expansion at 123 K and 10 K and high thermal conductivity, so it does not get easily deformed by thermal loads. One of the...
The French contribution to the LISA Consortium, specifically on the instrumental aspect, centers on developing optical ground support equipment (OGSE) for the validation of LISA's performance before it takes flight.
More specifically, one of the tasks of the French community is to test and validate the performance of the Interferometric Detection System (IDS).
The IDS Test Set-Up is...
The formation of black holes, especially those seen in Gaia binaries and gravitational wave events, is still not fully understood due to gaps in our knowledge of how massive stars evolve. Stellar winds play a key role in mass loss and significantly affect these evolutionary paths. However, existing models are hampered by outdated methods and considerable differences in their underlying...
Galactic core-collapse supernovae (CCSNe) are highly anticipated multi-messenger events, providing a natural laboratory where neutrinos, photons, and gravitational waves (GWs) can be observed together. Numerical simulations indicate that CCSN GW signals are inherently nondeterministic; however, they consistently exhibit a promising observable: the High-Frequency Feature (HFF), seen in...
An asymmetric rotating neutron star may emit quasi-monochromatic gravitational waves. Detecting such signals with second-generation detectors requires long observation times due to their low GW amplitudes. If the signal is also microlensed, the lens's mass temporarily magnifies the signal amplitude, aiding detection and providing a distinct microlensing pattern. We explore the prospects for...
Minimally modelled searches play a critical role in the detection of short-duration gravitational-wave transients whose morphologies are poorly constrained by existing waveform models. Among these approaches, the Coherent WaveBurst (cWB) algorithm has proven to be a robust and versatile tool for burst searches, enabling the coherent detection and reconstruction of gravitational-wave signals...
The suspended end mirror in the Input Mode Cleaner (IMC) cavity of the Advanced Virgo Plus interferometer was equipped with an enhanced baffle model in May 2021. This baffle is instrumented with active sensors next to the test mass to enable the monitoring of the scattered light in the cavity. We assess the performance and stability of the instrument after 4 years of operation. We study the...
Among the noises affecting GW detectors, Newtonian noise of seismic or acoustic origin could limit sensitivity at low frequencies, below a few tens of Hz. This presentation focuses on modeling Newtonian noise of acoustic origin, resulting from technical noises in caverns and experimental halls. A significant contribution to this technical noise is specifically linked to the operation of the...
