BinaryPulsarTiming.c File Reference

Functions to calculate binary system time delays and read TEMPO pulsar parameter files. More...

Prototypes
void	XLALComputeEccentricAnomaly (REAL8 phase, REAL8 ecc, REAL8 *u)
	XLAL function to compute the eccentric anomaly iteratively from Kelper's equation. More...
void	XLALComputeKopeikinTerms (KopeikinTerms *kop, BinaryPulsarParams *params, BinaryPulsarInput *in)
	XLAL function to compute Kopeikin terms that include the effect of binary orbital parameters of parallax. More...
void	XLALComputeKopeikinTermsNew (KopeikinTerms *kop, PulsarParameters *params, BinaryPulsarInput *in)
void	LALBinaryPulsarDeltaT (LALStatus *status, BinaryPulsarOutput *output, BinaryPulsarInput *input, BinaryPulsarParams *params)
	Calculate the binary system time delay using the pulsar parameters in params. More...
void	XLALBinaryPulsarDeltaT (BinaryPulsarOutput *output, BinaryPulsarInput *input, BinaryPulsarParams *params)
	XLAL function to compute the binary time delay. More...
void	XLALBinaryPulsarDeltaTNew (BinaryPulsarOutput *output, BinaryPulsarInput *input, PulsarParameters *params)
	function to calculate the binary system delay using new parameter structure More...

Detailed Description

Functions to calculate binary system time delays and read TEMPO pulsar parameter files.

Author

Matt Pitkin

Date

2006

Functions for calculating the timing delay to a signal from a pulsar in a binary system and reading pulsar parameters from TEMPO .par files. Models are taken from Taylor and Weisberg (1989) and use the naming conventions therein and used by TEMPO .

Prototypes

Description

The main function computes the time delay of a signal from a pulsar in a binary system due to doppler shifts and relativistic delays,

\begin{equation} \Delta{}t = t_\textrm{Roemer} + t_\textrm{Shapiro} + t_\textrm{Einstein} + t_\textrm{ Abberation}, \end{equation}

where \( t_\textrm{Roemer} \) is the light travel time, \( t_\textrm{Shapiro} \) is the General relativistic time delay, \( t_\textrm{Einstein} \) is the special relativistic time delay, and \( t_\textrm{Abberation} \) is the delay caused by the pulsars' rotation. There are several models of the binary systems, described in [27] , of which the four most common are so far implemented. The four models are the Blandford-Teukolsky model (BT) [3] , the low ellipticity model (ELL1) [15] , Damour-Deruelle model (DD) [5] , and the main sequence system model (MSS) [33] . These four models all use the five main binary parameters: the longitude of periastron \( \omega_0 \) , the eccentricity of the orbit \( e \) , the orbital period \( P \) , the time of periastron/or the time of ascension of the first node \( T_0 \) / \( T_{\textrm{asc}} \) , and the projected semi-major axis \( a\sin{}i \) . The are also many other model dependent parameters. These routines closely follow those used in the radio astronomy package TEMPO. A further model from TEMPO2 called T2 is also implemented in a basic form. The model is generally based on the DD model, but will convert to ELL1 if the eps parameters are set. At the moment this (T2) does not include multiple companions in the orbit, but does encompass the DDS model. It also can include Kopeikin terms that take account of the effect of the binary orbit on the parallax.

Radio astronomers fit pulsar parameters using TEMPO which will output the parameters in a .par file. The values allowed in this file can be found in the TEMPO documentation. A function is included to extract these parameters from the .par files and put them into a BinaryPulsarParams structure, it will set any unused parameters to zero or NULL. All parameters are in the units used by TEMPO with any conversion to SI units occuring within the binary timing routines. A function is also included which converts a string containing the right ascension or declination in the format ddd/hh:mm:ss.s or ddd/hhmmss.s (as is given in the .par file) into a REAL8 value in radians.

Notes

Definition in file BinaryPulsarTiming.c.

Go to the source code of this file.

Macros
#define	AULTSC   499.00478364 /* number of light seconds in AU (from tempo2.h) */

Macro Definition Documentation

AULTSC

#define AULTSC   499.00478364 /* number of light seconds in AU (from tempo2.h) */

Definition at line 98 of file BinaryPulsarTiming.c.

Function Documentation

XLALComputeEccentricAnomaly()

void XLALComputeEccentricAnomaly	(	REAL8	phase,
		REAL8	ecc,
		REAL8 *	u
	)

XLAL function to compute the eccentric anomaly iteratively from Kelper's equation.

This function will iteratively calculate the eccentric anomaly from Kelper's equation.

Definition at line 104 of file BinaryPulsarTiming.c.

XLALComputeKopeikinTerms()

void XLALComputeKopeikinTerms	(	KopeikinTerms *	kop,
		BinaryPulsarParams *	params,
		BinaryPulsarInput *	in
	)

XLAL function to compute Kopeikin terms that include the effect of binary orbital parameters of parallax.

This function will compute the effect of binary parameters on the pulsar parallax.

Definition at line 120 of file BinaryPulsarTiming.c.

XLALComputeKopeikinTermsNew()

void XLALComputeKopeikinTermsNew	(	KopeikinTerms *	kop,
		PulsarParameters *	params,
		BinaryPulsarInput *	in
	)

Definition at line 242 of file BinaryPulsarTiming.c.

LALBinaryPulsarDeltaT()

void LALBinaryPulsarDeltaT	(	LALStatus *	status,
		BinaryPulsarOutput *	output,
		BinaryPulsarInput *	input,
		BinaryPulsarParams *	params
	)

Calculate the binary system time delay using the pulsar parameters in params.

Definition at line 390 of file BinaryPulsarTiming.c.

XLALBinaryPulsarDeltaT()

void XLALBinaryPulsarDeltaT	(	BinaryPulsarOutput *	output,
		BinaryPulsarInput *	input,
		BinaryPulsarParams *	params
	)

XLAL function to compute the binary time delay.

function to calculate the binary system delay

Definition at line 431 of file BinaryPulsarTiming.c.

XLALBinaryPulsarDeltaTNew()

void XLALBinaryPulsarDeltaTNew	(	BinaryPulsarOutput *	output,
		BinaryPulsarInput *	input,
		PulsarParameters *	params
	)

function to calculate the binary system delay using new parameter structure

Definition at line 935 of file BinaryPulsarTiming.c.