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Function: mc_chirp()
void mc_chirp(float time, float latitude, float orientation, long *seed,
float *invMpc, float *c0, float *c1)
This routine makes a random chirp from a hypothetical distribution of Galactic
binary neutron stars. The arguments are:
 time: Input. The time of arrival of the chirp in sidereal
seconds.
 latitude: Input. The latitude of the detector in radians
North.
 orientation: Input. The orientation of the arm of the detector
in radians counter clockwise from North.
 seed: Input/Output. A random number seed for use in the
Numerical Recipes random number generator ran1().
 invMpc: Output. The effective distance of the chirp, i.e.,
the distance of the binary system if it were optimally oriented.
 c0: Output. The cosine of the random phase of the chirp.
 c1: Output. The sine of the random phase of the chirp.
The resulting chirp waveform is
where is the cosinephase chirp waveform and is the
sinephase chirp waveform normalized to one megaparsec.
The hypothetical number of Galactic binary neutron star systems between the
Galactocentric radii and , and between disk heights and ,
is taken to be

(12.7.286) 
with
and
. Only the disk population
is considered in this calculation. The Galactocentric radius of the Sun
is taken to be
.
 Author: Jolien Creighton, jolien@tapir.caltech.edu
 Comments: The hypothetical distribution was adapted from the
distribution used by S. J. Curran and D. R. Lorimer,
Mon. Not. R. Astron. Soc. 276 347 (1995). The scale
height is a guestimate. Very little is known about the actual distribution
of Galactic neutron star binaries! The routine assumes that the arms of the
detector are perpendicular; it is not suitable for the
GEO600 site because the opening angle is approximately .
Next: Example: inject program
Up: Galactic Modelling
Previous: Function: beam_pattern()
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Bruce Allen
20001119