Statistics of the detection rates for tensor and scalar gravitational waves from the Local Galaxy universe

Abstract

Abstract. We use data on the local 3-dimensional galaxy distribution for studying the statistics of the detection rates of gravitational waves (GW) coming from supernova explosions. We consider both tensor and scalar gravitational waves which are possible in a wide range of relativistic and quantum gravity theories. We show that statistics of GW events as a function of sidereal time can be used for distinction between scalar and tensor gravitational waves because of the anisotropy of spatial galaxy distribution. For calculation of the expected amplitudes of GW signals we use the values of the released GW energy, frequency and duration of GW pulse which are consistent with existing scenarios of SN core collapse. The amplitudes of the signals produced by Virgo and the Great Attractor clusters of galaxies is expressed as a function of the sidereal time for resonant bar detectors operating now (IGEC) and for forthcoming laser interferometric detectors (VIRGO). Then, we calculate the expected number of GW events as a function of sidereal time produced by all the galaxies within 100 Mpc. In the case of axisymmetric rotational core collapse which radiates a GW energy of 10 −9 M c 2 , only the closest explosions can be detected. However, in the case of nonaxisymmetric supernova explosion, due to such phenomena as centrifugal hangup, bar and lump formation, the GW radiation could be as strong as that from a coalescing neutron-star binary. For radiated GW energy higher than 10 −6 M c 2 and sensitivity of detectors at the level h ≈ 10 −23 it is possible to detect Virgo cluster and Great Attractor, and hence to use the statistics of GW events for testing gravity theories.

Possible sources of gravitational wave bursts detectable today

“…[7][8][9]. The purpose of this section is to discuss in detail what we can learn about the location (and possibly the polarization) of the sources from the sidereal time analysis.…”

“…We also mention that the sidereal time analysis can be very useful even in the study of extragalactic sources [7,8]. However, eq.…”

Detection of a close supernova gravitational wave burst in a network of interferometers, neutrino and optical detectors

“…by Ref. [14], the power one can extract from a fit of the supernova rate beyond the Virgo cluster is close to 2.2, i.e. below the value of 3 which would correspond to a uniform density of sources.…”

“…[14] where a much larger catalog of galaxies and higher supernova rates -thus leading to more optimistic predictions -have been used. As shown later in Section 2.3, only close supernovae are expected to be visible in interferometers; therefore, the Tully catalog is enough to estimate the detectable rate of events and no significant correction taking into account galaxies with apparent magnitudes too low to be observed is required.…”

Considerations on coincidence experiments between two gravitational wave detectors for sources in the Galactic Centre

“…Thus we can observe a clear modulation only if the signals have amplitude near the threshold, so that when the absorbed energy goes below the threshold then few or no events are generated. Calculations have already been made (Baryshev & Paturel 2001;Paturel & Baryshev 2003) for the expected sidereal time behavior of different detectors but not for coincidence experiments and without taking into account the effect of the noise. Indeed, one should also consider that the generation of an event depends strongly on the combination of the signal induced by the GW with the detector noise (Astone e al.…”