next up previous contents
Next: Function: merger_dist() Up: GRASP Routines: Gravitational Radiation Previous: The effective distance to   Contents


Function: inspiral_dist()

void inspiral_dist(double *deff, double *z, double *Vc, double m1_z,
                   double m2_z, double snr, double S_h[], int npoint,
                   double srate, double h100)
This function computes the effective distance to which a binary inspiral with redshifted masses m1_z and m2_z can be seen with the noise spectrum S_h[].

It uses the energy spectrum

\begin{displaymath}
{dE_{\rm gw}\over df} = {\pi^{2/3} \over 3}\mu M^{2/3} f^{-1/3}
\end{displaymath} (6.33.157)

to describe the inspiral for frequencies $f < f_{\rm merge} = 0.02/M$, and zero above $f_{\rm merge}$ (as in reference [13]). To convert from luminosity distance to redshift, it assumes a universe flat cosmology ($\Lambda=0$, $\Omega=1$) with a Hubble constant $H_0 =
75\,{\rm km}/{{\rm Mpc}\,{\rm sec}}$, and uses an Eq. (11) from [18]. To convert from redshift to comoving volume, it uses Eq. (27) of [19] or Eq. (2.56) with $q_0=1/2$ of [20].

The arguments to the function are:

deff: Output. The effective distance in megaparsecs.
z: Output. Redshift corresponding that effective distance.
Vc: Output. Comoving volume at the redshift in cubic megaparsecs.
m1_z: Input. Redshifted mass one, $(1+z)m_1$.
m2_z: Input. Redshifted mass two, $(1+z)m_2$.
snr: Input. The signal-to-noise ratio at which the effective distance is deff.
S_h: Input. The spectral density of noise in Hz$^{-1}$.
npoint: Input. The number of data points in S_h.
srate: Input. The sampling rate used to construct the noise spectrum, Hz.
h100: Input. The Hubble constant in units of 100 km/sec/Mpc.

Author: Scott Hughes, hughes@tapir.caltech.edu


next up previous contents
Next: Function: merger_dist() Up: GRASP Routines: Gravitational Radiation Previous: The effective distance to   Contents
Bruce Allen 2000-11-19