VIRGO detector optimization for gravitational waves by inspiralling binaries

Abstract

For future configurations, we study the relation between the abatement of the noise sources and the Signal to Noise Ratio (SNR) for coalescing binaries. Our aim is not the proposition of a new design, but an indication of where in the bandwidth or for which noise source, a noise reduction would be most efficient. We take VIRGO as the reference for our considerations, solely applicable to the inspiralling phase of a coalescing binary. Thus, only neutron stars and small black holes of few solar masses are encompassed by our analysis. The contributions to the SNR given by final merge and quasi-normal ringing are neglected. It is identified that i) the reduction in the mirror thermal noise band provides the highest gain for the SNR, when the VIRGO bandwidth is divided according to the dominant noises; ii) it exists a specific frequency at which lies the potential largest increment in the SNR, and that the enlargement of the bandwidth, where the noise is reduced, produces a shift of such optimal frequency to higher values; iii) the abatement of the pendulum thermal noise provides the largest, but modest, gain, when noise sources are considered separately. Our recent astrophysical analysis on event rates for neutron stars leads to a detection rate of one every 148 or 125 years for VIRGO and LIGO, respectively, while a recently proposed and improved, but still conservative, VIRGO configuration would provide an increase to 1.5 events per year. Instead, a bi-monthly event rate, similar to advanced LIGO, requires a 16 times gain. We analyse the 3D (pendulum, mirror, shot noises) parameter space showing how such gain could be achieved.

The eccentricity distribution of compact binaries

“…Both detectors will undergo serious improvements to increase their sensitivity (Smith and LIGO Scientific Collaboration 2009;Spallicci et al 2005).…”

“…As the interferometric gravitational wave detectors LIGO and VIRGO (Harry & the LIGO Scientific Collaboration 2010; Acernese et al 2006) reach their design sensitivities, the first detection of gravitational waves has become more imminent. Both detectors will undergo serious improvements to increase their sensitivity (Smith & LIGO Scientific Collaboration 2009;Spallicci et al 2005).…”

Measuring a Cosmological Distance-Redshift Relationship Using Only Gravitational Wave Observations of Binary Neutron Star Coalescences

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Solar wind test of the de Broglie-Proca massive photon with Cluster multi-spacecraft data

“…We have just witnessed the opening of the gravitational wave window on the universe [1,2]. Nevertheless, our understanding of the universe at large and small scales will continue to rely also on electromagnetic observations.…”

“…In [40], still Ryutov refers to Voyager 1 and Voyager 2 data appeared in previous work [51][52][53] to justify strict use of Parker's model, and to adopt the reductio ad absurdum approach already used in [39]. Indeed, on the basis that the magnetic field is almost entirely azimuthal, Ryutov considers that the Lorentz force would be increased of a factor (L B /Ż) 2 , where L B is the magnetic field characteristic length, with respect to the Maxwellian case. Since the deviations from the observed flow structure would become grossly incompatible with the real situation, the mass upper limit is lowered to 1.5 × 10 −54 kg at 40 AU.…”