Scaling Correlations Among Central Massive Objects and Their Host Galaxies

The central regions of galaxies show the presence of super massive black holes and/or very dense stellar clusters. Both such objects seem to follow similar host-galaxy correlations, suggesting that they are members of the same family of Compact Massive Objects. Here we investigate a huge data collection of Compact Massive Objects properties to correlate them with absolute magnitude, velocity dispersion and mass of their host galaxies. We draw also some preliminary astrophysical conclusions

Search for gravitational-wave bursts in LIGO data at the Schenberg antenna sensitivity range

The Brazilian gravitational-wave detector Mario Schenberg was conceived in the early 2000s and operated until 2016 when it was dismantled. A straight path to evaluate the viability of the reassembly of the Schenberg antenna is to verify the possibility of detecting gravitational wave (GW) signals within its design sensitivity features. The eventual identification of significant signals would operate as motivation for the Schenberg rebuild. As the antenna was dismantled, we can get some indication from the third observing run (O3) data of the LIGO detectors. It is based on the similarity between Schenberg sensitivity and the sensitivity of the interferometers in the O3 [3150-3260] Hz band. We search for signals with milliseconds to a few seconds without making assumptions about their morphology, polarization, and arrival sky direction. The data were analyzed with the coherent WaveBurst pipeline (cWB) with frequencies from 512 Hz to 4096 Hz and the search targets only signals with bandwidth overlapping the Schenberg frequency band. No statistically significant evidence of GW bursts during O3 was found. The null result was used to feature the search efficiency in identifying different simulated signal morphologies and establish upper limits on the GW burst event rate as a function of its strain amplitude. The present search, and consequently Schenberg, is sensitive to sources emitting isotropically 5 x 10e(-6) M_sun c^2 in GWs from a distance of 10 kpc with 50% detection efficiency and with a false alarm rate of 1/100 years. The feasibility of detecting f-modes of neutron stars excited by glitches was also investigated. The Schenberg antenna would need at least 5.3 years of observation run to get a single detection of the f-mode signal, given E_(glitch) approx 10e(-10) M_sun c^2

Research Facilities for Europe’s Next Generation Gravitational-Wave Detector Einstein Telescope

peer reviewedThe Einstein Telescope is Europe’s next generation gravitational-wave detector. To develop all necessary technology, four research facilities have emerged across Europe: The Amaldi Research Center (ARC) in Rome (Italy), ETpathfinder in Maastricht (The Netherlands), SarGrav in the Sos Enattos mines on Sardinia (Italy) and E-TEST in Liége (Belgium) and its surroundings. The ARC pursues the investigation of a large cryostat, equipped with dedicated low-vibration cooling lines, to test full-scale cryogenic payloads. The installation will be gradual and interlaced with the payload development. ETpathfinder aims to provide a low-noise facility that allows the testing of full interferometer configurations and the interplay of their subsystems in an ET-like environment. ETpathfinder will focus amongst others on cryogenic technologies, silicon mirrors, lasers and optics at 1550 and 2090 nm and advanced quantum noise reduction schemes. The SarGrav laboratory has a surface lab and an underground operation. On the surface, the Archimedes experiment investigates the interaction of vacuum fluctuations with gravity and is developing (tilt) sensor technology for the Einstein Telescope. In an underground laboratory, seismic characterisation campaigns are undertaken for the Sardinian site characterisation. Lastly, the Einstein Telecope Euregio meuse-rhine Site & Technology (E-TEST) is a single cryogenic suspension of an ET-sized silicon mirror. Additionally, E-TEST investigates the Belgian–Dutch–German border region that is the other candidate site for Einstein Telescope using boreholes and seismic arrays and hydrogeological characterisation. In this article, we describe the Einstein Telescope, the low-frequency part of its science case and the four research facilities

Quantum zero point electromagnetic energy difference between the superconducting and the normal phase in a high-<math><msub><mi>T</mi><mi>c</mi></msub></math> superconducting metal bulk sample

International audienceWe provide a methodological approach to the estimate of the change of the quantum vacuum electromagnetic energy density in a high critical temperature superconducting metal bulk sample, when it undergoes the transition in temperature, from the superconducting to the normal phase. The various contributions to the Casimir energy in the two phases are highlighted and compared. While the transverse magnetic polarization of the vacuum mode allows for a macroscopic description of the superconducting transition, the changes in the transverse electric vacuum mode induced by the superconductive correlations are introduced within a microscopic model, which does not explicitly take into account the anisotropic structure of the material

Casimir energy for N superconducting cavities: a model for the YBCO (GdBCO) sample to be used in the Archimedes experiment

International audienceAbstract In this paper we study the Casimir energy of a sample made by N cavities, with $$N\gg 1$$ N ≫ 1 , across the transition from the metallic to the superconducting phase of the constituting plates. After having characterised the energy for the configuration in which the layers constituting the cavities are made by dielectric and for the configuration in which the layers are made by plasma sheets, we concentrate our analysis on the latter. It represents the final step towards the macroscopical characterisation of a “multi-cavity” (with N large) necessary to fully understand the behaviour of the Casimir energy of a YBCO (or a GdBCO) sample across the transition. Our analysis is especially useful to the Archimedes experiment, aimed at measuring the interaction of the electromagnetic vacuum energy with a gravitational field. To this purpose, we aim at modulating the Casimir energy of a layered structure, the multi-cavity, by inducing a transition from the metallic to the superconducting phase. After having characterised the Casimir energy of such a structure for both the metallic and the superconducting phase, we give an estimate of the modulation of the energy across the transition

Open data from the first and second observing runs of Advanced LIGO and Advanced Virgo

Advanced LIGO and Advanced Virgo are monitoring the sky and collecting gravitational-wave strain data with sufficient sensitivity to detect signals routinely. In this paper we describe the data recorded by these instruments during their first and second observing runs. The main data products are gravitational-wave strain time series sampled at 16384 Hz. The datasets that include this strain measurement can be freely accessed through the Gravitational Wave Open Science Center at http://gw-openscience.org, together with data-quality information essential for the analysis of LIGO and Virgo data, documentation, tutorials, and supporting software

Search for intermediate-mass black hole binaries in the third observing run of Advanced LIGO and Advanced Virgo

International audienceIntermediate-mass black holes (IMBHs) span the approximate mass range 100−105 M⊙, between black holes (BHs) that formed by stellar collapse and the supermassive BHs at the centers of galaxies. Mergers of IMBH binaries are the most energetic gravitational-wave sources accessible by the terrestrial detector network. Searches of the first two observing runs of Advanced LIGO and Advanced Virgo did not yield any significant IMBH binary signals. In the third observing run (O3), the increased network sensitivity enabled the detection of GW190521, a signal consistent with a binary merger of mass ∼150 M⊙ providing direct evidence of IMBH formation. Here, we report on a dedicated search of O3 data for further IMBH binary mergers, combining both modeled (matched filter) and model-independent search methods. We find some marginal candidates, but none are sufficiently significant to indicate detection of further IMBH mergers. We quantify the sensitivity of the individual search methods and of the combined search using a suite of IMBH binary signals obtained via numerical relativity, including the effects of spins misaligned with the binary orbital axis, and present the resulting upper limits on astrophysical merger rates. Our most stringent limit is for equal mass and aligned spin BH binary of total mass 200 M⊙ and effective aligned spin 0.8 at 0.056 Gpc−3 yr−1 (90% confidence), a factor of 3.5 more constraining than previous LIGO-Virgo limits. We also update the estimated rate of mergers similar to GW190521 to 0.08 Gpc−3 yr−1.Key words: gravitational waves / stars: black holes / black hole physicsCorresponding author: W. Del Pozzo, e-mail: [email protected]† Deceased, August 2020