The pattern of the two detectors Explorer and Nautilus to signals due to these models are shown in Fig. 2. These patterns are all given as a function of the sidereal time. depends on the space and energy distributions of g.w. sources described by a model, taking also into account the variation of the detector efficiency with the sidereal time, due to the varying orientation of the antennae respect to the sources. It depends also on the (unknown) energies of g.w. signals, on the noise, and on the coordinates (latitude,longitude,azimuth) of the detectors on Earth. Simply speaking, for various models of the space distribution of sources of g.w., we expect different responses from the coincidence experiment, i.e. different `antenna patterns', seen as a function of the sidereal time.
The calculation of depends on the expected g.w. energy and some assumptions are needed. The signal's amplitude is unknown, and thus we have evaluated the patterns by integrating over a uniform distribution of values, ranging - on Earth - from up to . Different reasonings may be done here, leading to different choices for the amplitudes range and for the distributions of the signals. We have done the simplest choice, supposing that we do not know anything on the signals, but the fact that no signals have been observed at the detectors with amplitude greater than . The lowest limit has been chosen considering the fact that the detector's efficiencies below is very small (less than ). Note that the considered values are based on `standard' assumptions about the g.w. energy release in cryogenic bars. The Galactic Disk (GD) model has been constructed considering g.w. sources uniformly distributed over the Galactic plane, which means a distribution of sources which is not uniform around the Earth, given the fact that the Earth is kpc from the Center of Galaxy, which is the center of the disk (whose radius is kpc). The GMD distribution, taking into account the mass distribution in Galaxy, is much more interesting than the GD model. In fact we do not expect a uniform distribution of the sources over the GD, but a distribution which is concentrated near the GC .