4 research outputs found
Status of the joint LIGO--TAMA300 inspiral analysis
We present the status of the joint search for gravitational waves from
inspiraling neutron star binaries in the LIGO Science Run 2 and TAMA300 Data
Taking Run 8 data, which was taken from February 14 to April 14, 2003, by the
LIGO and TAMA collaborations. In this paper we discuss what has been learned
from an analysis of a subset of the data sample reserved as a ``playground''.
We determine the coincidence conditions for parameters such as the coalescence
time and chirp mass by injecting simulated Galactic binary neutron star signals
into the data stream. We select coincidence conditions so as to maximize our
efficiency of detecting simulated signals. We obtain an efficiency for our
coincident search of 78 %, and show that we are missing primarily very distant
signals for TAMA300. We perform a time slide analysis to estimate the
background due to accidental coincidence of noise triggers. We find that the
background triggers have a very different character from the triggers of
simulated signals.Comment: 10 page, 8 figures, accepted for publication in Classical and Quantum
Gravity for the special issue of the GWDAW9 Proceedings ; Corrected typos,
minor change
Orbital effects of a monochromatic plane gravitational wave with ultra-low frequency incident on a gravitationally bound two-body system
We analytically compute the long-term orbital variations of a test particle
orbiting a central body acted upon by an incident monochromatic plane
gravitational wave. We assume that the characteristic size of the perturbed
two-body system is much smaller than the wavelength of the wave. Moreover, we
also suppose that the wave's frequency is much smaller than the particle's
orbital one. We make neither a priori assumptions about the direction of the
wavevector nor on the orbital geometry of the planet. We find that, while the
semi-major axis is left unaffected, the eccentricity, the inclination, the
longitude of the ascending node, the longitude of pericenter and the mean
anomaly undergo non-vanishing long-term changes. They are not secular trends
because of the slow modulation introduced by the tidal matrix coefficients and
by the orbital elements themselves. They could be useful to indepenedently
constrain the ultra-low frequency waves which may have been indirectly detected
in the BICEP2 experiment. Our calculation holds, in general, for any
gravitationally bound two-body system whose characteristic frequency is much
larger than the frequency of the external wave. It is also valid for a generic
perturbation of tidal type with constant coefficients over timescales of the
order of the orbital period of the perturbed particle.Comment: LaTex2e, 24 pages, no figures, no tables. Changes suggested by the
referees include