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Structure: struct chirp_template

The following data structure is used to carry information about the position of a chirp template in a variety of coordinate systems, from the most specific computational parameters (its index in an enumerated list) to the most general physical parameters (the masses of its binary components). In many cases the transformations among these coordinates depend on additional parameters, such as the reference frequency for the $\tau_0,\tau_1$ coordinates, or the angle between the $\tau_0$ and $x$ axes; this global information is typically stored in a data structure of type struct chirp_space (section [*]). In addition, the following structure contains some information about the size of the coordinate patch covered by the template. The fields are:

struct chirp_template {

int flag; An indicator of any errors which occured while generating or placing this template. At present, the following codes are recognized:
$-$1: Template is incomplete; some fields could not be filled.
0: No errors occured.
1: Possible uncovered region of parameter space near the corners of this template.
2: Template placement terminated prematurely at this template, due to a metric singularity.
3: Template placement terminated prematurely at this template, for some other reason.

int num; The index of the template in an enumerated list, normally ranging from 0 to the number of templates $-1$.

double x; The $x$ coordinate of the template in a computational Cartesian coordinate system. Normally this system is related to the $\tau_0,\tau_1$ coordinate system by a simple rotation, so it has units of seconds.

double y; As above, but the $y$ coordinate.

double dx; The width in the $x$ direction of a rectangular patch about the template, which is inscribed within an equimatch ellipse.

double dy; The height in the $y$ direction of the rectangular patch.

double semimajor; The length of the semimajor axis of the equimatch ellipse circumscribing the template patch.

double semiminor; The length of the semiminor axis of the equimatch ellipse circumscribing the template patch.

double theta; The angle counterclockwise from the $x$ axis to the semimajor axis (radians).

double tau0; The 0th order post-Newtonian time to coalescence (seconds).

double tau1; The 1st order post-Newtonian correction to the time to coalescence (seconds).

double mtotal; The total mass of the binary system (solar masses).

double mchirp; The chirp mass of the system (solar masses).

double mred; The reduced mass of the system (solar masses).

double eta; The ratio of the reduced mass to the total mass.

double m1; The mass of one of the binary components (by convention, the larger), in solar masses.

double m2; The mass of the other binary component (by convention, the smaller), in solar masses.

};


next up previous contents
Next: Function: set_chirp_space Up: GRASP Routines: Template Bank Previous: Structure: struct chirp_space   Contents
Bruce Allen 2000-11-19