Timing Models
PINT, like TEMPO and TEMPO2, support many different ways of calculating pulse
arrival times. The key tool for doing this is a
TimingModel object, through which a whole
range of Parameter are accessible. The actual
computation is done by pieces of code that live in
Component; during the parsing of a parameter
file, these are selected based on the parameters present. Binary models are
selected explicitly using the BINARY parameter, while each non-binary
component is selected if some parameter unique to it is included (for example
if ELAT is present, AstrometryEcliptic is
selected). Ambiguous or contradictory parameter files are possible, and for
these PINT raises an exception.
Components supported by PINT:
AbsPhase- Absolute phase model.AstrometryEcliptic- Astrometry in ecliptic coordinates.AstrometryEquatorial- Astrometry in equatorial coordinates.BinaryBT- Blandford and Teukolsky binary model. (BINARY BT)BinaryBTPiecewise- BT model with piecewise orbital parametersA1XandT0X. This model lets the user specify time ranges and fit for a different piecewise orbital parameter in each time range. (BINARY BT_piecewise)BinaryDD- Damour and Deruelle binary model. (BINARY DD)BinaryDDGR- Damour and Deruelle model assuming GR to be correct (BINARY DDGR)BinaryDDH- DD modified to use H3/STIGMA parameter for Shapiro delay. (BINARY DDH)BinaryDDK- Damour and Deruelle model with kinematics. (BINARY DDK)BinaryDDS- Damour and Deruelle model with alternate Shapiro delay parameterization. (BINARY DDS)BinaryELL1- ELL1 binary model. (BINARY ELL1)BinaryELL1H- ELL1 modified to use H3 parameter for Shapiro delay. (BINARY ELL1H)BinaryELL1k- ELL1k binary model. (BINARY ELL1k)CMWaveX- Fourier representation of chromatic variations.ChromaticCM- Simple chromatic delay model with a constant chromatic index.ChromaticCMX- This class provides a CMX model - piecewise-constant chromatic variations with constantDMWaveX- Fourier representation of DM variations.DispersionDM- Simple DM dispersion model.DispersionDMX- This class provides a DMX model - piecewise-constant DM variations.DispersionJump- This class provides the constant offsets to the DM values.EcorrNoise- Noise correlated between nearby TOAs.FD- A timing model for frequency evolution of pulsar profiles.FDJump- A timing model for system-dependent frequency evolution of pulsarFDJumpDM- This class provides system-dependent DM offsets for narrow-bandGlitch- Pulsar spin-down glitches.IFunc- This class implements tabulated delays.PLChromNoise- Model of a radio frequency-dependent noise with a power-law spectrum and arbitrary chromatic index.PLDMNoise- Model of DM variations as radio frequency-dependent noise with a power-law spectrum.PLRedNoise- Timing noise with a power-law spectrum.PhaseJump- Arbitrary jumps in pulse phase.PhaseOffset- Explicit pulse phase offset between physical TOAs and the TZR TOA.PiecewiseSpindown- Pulsar spin-down piecewise solution.ScaleDmError- Correction for estimated wideband DM measurement uncertainty.ScaleToaError- Correct reported template fitting uncertainties.SolarSystemShapiro- Shapiro delay due to light bending near Solar System objects.SolarWindDispersion- Dispersion due to the solar wind (basic model).SolarWindDispersionX- This class provides a SWX model - multiple Solar Wind segments.Spindown- A simple timing model for an isolated pulsar.TroposphereDelay- Model for accounting for the troposphere delay for topocentric TOAs.Wave- Delays expressed as a sum of sinusoids.WaveX- Implementation of the wave model as a delay correction, with delays are expressed as a sum of sinusoids.
Supported Parameters
The following table lists all the parameters that PINT can understand (along with their aliases). The model components that use them (linked below) should give more information about how they are interpreted.
Some parameters PINT understands have aliases - for example, the parameter PINT
calls “ECC” may also be written as “E” in parameter files. PINT will understand
these parameter files, but will always refer to this parameter internally as
“ECC”. By default, though, when PINT reads a parameter file, PINT will remember
the alias that was used, and PINT will write the model out using the same
alias. This can be controlled by the use_alias attribute of
Parameter objects.
PINT support for families of parameters, either specified by prefix (F0,
F1, F2, … or DMX_0017, DMX_0123, …) or selecting subsets of
parameters based on flags (JUMP -tel AO). These are indicated in the table
with square brackets. Note that like the frequency derivatives, these families
may have units that vary in a systematic way.
Parameters can also have different types. Most are long double floating point,
with or without units; these can be specified in the usual 1.234e5 format,
although they also support 1.234d5 as well as capitalized versions for
compatibility. One or two parameters - notably A1DOT - can accept a value
scaled by 1e12, automatically rescaling upon read; although this is
confusing, it is necessary because TEMPO does this and so there are parameter
files “in the wild” that use this feature. Other data types allow input of
different formats, for example RAJ 10:23:47.67; boolean parameters allow
1/0, Y/N, T/F, YES/NO, TRUE/FALSE, or
lower-case versions of these.
Name / Aliases |
Description |
Kind |
Components |
|---|---|---|---|
A0 |
DD model aberration parameter A0 |
s |
|
A1 |
Projected semi-major axis of pulsar orbit, ap*sin(i) |
ls |
|
A1DOT / XDOT |
Derivative of projected semi-major axis, d[ap*sin(i)]/dt |
ls / s |
|
A1X_{number} |
ParameterA1variation |
ls |
|
B0 |
DD model aberration parameter B0 |
s |
|
BINARY |
Pulsar System/Binary model |
string |
|
CHI2 |
Chi-squared value obtained during fitting |
number |
|
CHI2R |
Reduced chi-squared value obtained during fitting |
number |
|
CLOCK / CLK |
Timescale to use |
string |
|
CM |
Chromatic measure |
pc / (MHz2 cm3) |
|
CMEPOCH |
Epoch of CM measurement |
d |
|
CMWXCOS_{number} |
Cosine amplitudes for Fourier representation of chromatic noise |
pc / (MHz2 cm3) |
|
CMWXEPOCH |
Reference epoch for Fourier representation of chromatic noise |
d |
|
CMWXFREQ_{number} |
Component frequency for Fourier representation of chromatic noise |
1 / d |
|
CMWXSIN_{number} |
Sine amplitudes for Fourier representation of chromatic noise |
pc / (MHz2 cm3) |
|
CMXR1_{number} |
Beginning of CMX interval |
d |
|
CMXR2_{number} |
End of CMX interval |
d |
|
CMX_{number} |
Dispersion measure variation |
pc / (MHz2 cm3) |
|
CM{number} |
1’th time derivative of the chromatic measure |
pc / (yr MHz2 cm3) |
|
CORRECT_TROPOSPHERE |
Enable Troposphere Delay Model |
boolean |
|
DECJ / DEC |
Declination (J2000) |
deg |
|
DILATEFREQ |
Whether or not TEMPO2 should apply gravitational redshift and time dilation to observing frequency (Y/N; PINT only supports N) |
boolean |
|
DM |
Dispersion measure |
pc / cm3 |
|
DMDATA |
Was the fit done using per-TOA DM information? |
boolean |
|
DMEFAC {flag} {value} |
A multiplication factor on the measured DM uncertainties, |
number |
|
DMEPOCH |
Epoch of DM measurement |
d |
|
DMEQUAD {flag} {value} |
An error term added in quadrature to the scaled (by EFAC) TOA uncertainty. |
pc / cm3 |
|
DMJUMP {flag} {value} |
Wideband DM value offset. |
pc / cm3 |
|
DMRES |
DM residual after fitting (wideband only) |
pc / cm3 |
|
DMWXCOS_{number} |
Cosine amplitudes for Fourier representation of DM noise |
dmu |
|
DMWXEPOCH |
Reference epoch for Fourier representation of DM noise |
d |
|
DMWXFREQ_{number} |
Component frequency for Fourier representation of DM noise |
1 / d |
|
DMWXSIN_{number} |
Sine amplitudes for Fourier representation of DM noise |
dmu |
|
DMX |
Dispersion measure |
pc / cm3 |
|
DMXR1_{number} |
Beginning of DMX interval |
d |
|
DMXR2_{number} |
End of DMX interval |
d |
|
DMX_{number} |
Dispersion measure variation |
pc / cm3 |
|
DM{number} |
1’th time derivative of the dispersion measure |
pc / (yr cm3) |
|
DR |
Relativistic deformation of the orbit |
number |
|
DTH / DTHETA |
Relativistic deformation of the orbit |
number |
|
ECC / E |
Eccentricity |
number |
|
ECL |
Obliquity of the ecliptic (reference) |
string |
|
ECORR {flag} {value} / TNECORR {flag} {value} |
An error term that is correlated among all TOAs in an observing epoch. |
us |
|
EDOT |
Eccentricity derivative respect to time |
1 / s |
|
EFAC {flag} {value} / T2EFAC {flag} {value}, TNEF {flag} {value} |
A multiplication factor on the measured TOA uncertainties, |
number |
|
ELAT / BETA |
Ecliptic latitude |
deg |
|
ELONG / LAMBDA |
Ecliptic longitude |
deg |
|
EPHEM |
Ephemeris to use |
string |
|
EPS1 |
First Laplace-Lagrange parameter, ECC*sin(OM) |
number |
|
EPS1DOT |
First derivative of first Laplace-Lagrange parameter |
1e-12 / s |
|
EPS2 |
Second Laplace-Lagrange parameter, ECC*cos(OM) |
number |
|
EPS2DOT |
Second derivative of first Laplace-Lagrange parameter |
1e-12 / s |
|
EQUAD {flag} {value} / T2EQUAD {flag} {value} |
An error term added in quadrature to the scaled (by EFAC) TOA uncertainty. |
us |
|
FB{number} |
0th time derivative of frequency of orbit |
1 / s |
|
FD10JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 10 |
s |
|
FD11JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 11 |
s |
|
FD12JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 12 |
s |
|
FD13JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 13 |
s |
|
FD14JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 14 |
s |
|
FD15JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 15 |
s |
|
FD16JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 16 |
s |
|
FD17JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 17 |
s |
|
FD18JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 18 |
s |
|
FD19JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 19 |
s |
|
FD1JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 1 |
s |
|
FD20JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 20 |
s |
|
FD2JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 2 |
s |
|
FD3JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 3 |
s |
|
FD4JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 4 |
s |
|
FD5JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 5 |
s |
|
FD6JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 6 |
s |
|
FD7JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 7 |
s |
|
FD8JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 8 |
s |
|
FD9JUMP {flag} {value} |
System-dependent FD parameter of polynomial index 9 |
s |
|
FDJUMPDM {flag} {value} |
System-dependent DM offset. |
pc / cm3 |
|
FDJUMPLOG |
Whether to use log-frequency (Y) or linear-frequency (N) for computing FDJUMPs. |
boolean |
|
FD{number} |
Polynomial coefficient of log-frequency-dependent delay |
s |
|
FINISH |
End MJD for fitting |
d |
|
F{number} |
Spin-frequency |
Hz |
|
GAMMA |
Time dilation & gravitational redshift |
s |
|
GLEP_{number} |
Epoch of glitch 1 |
d |
|
GLF0D_{number} |
Decaying frequency change for glitch 1 |
Hz |
|
GLF0_{number} |
(‘Permanent frequency change for glitch 1’,) |
Hz |
|
GLF1_{number} |
(‘Permanent frequency-derivative change for glitch 1’,) |
Hz / s |
|
GLF2_{number} |
(‘Permanent second frequency-derivative change for glitch 1’,) |
Hz / s2 |
|
GLPH_{number} |
Phase change for glitch 1 |
number |
|
GLTD_{number} |
Decay time constant for glitch 1 |
d |
|
H3 |
Shapiro delay parameter H3 as in Freire and Wex 2010 Eq(20) |
s |
|
H4 |
Shapiro delay parameter H4 as in Freire and Wex 2010 Eq(21) |
s |
|
IFUNC{number} |
Interpolation control point pair (MJD, delay) |
s |
|
INFO |
Tells TEMPO to write some extra information about frontend/backend combinations; -f is recommended |
string |
|
JUMP {flag} {value} |
Phase jump for selection. |
s |
|
K96 |
Flag for Kopeikin binary model proper motion correction |
boolean |
|
KIN |
Inclination angle |
deg |
|
KINIAU |
Inclination angle in the IAU convention |
deg |
|
KOM |
The longitude of the ascending node |
deg |
|
KOMIAU |
The longitude of the ascending node in the IAU convention |
deg |
|
LNEDOT |
Log-derivative of the eccentricity EDOT/ECC |
1 / yr |
|
M2 |
Companion mass |
solMass |
|
MP |
Pulsar mass |
solMass |
|
MTOT |
Total system mass in units of Solar mass |
solMass |
|
NE_SW / NE1AU, SOLARN0 |
Solar Wind density at 1 AU |
1 / cm3 |
|
NE_SW{number} |
1’th time derivative of the Solar Wind density at 1 AU |
1 / (yr cm3) |
|
NHARMS |
Number of harmonics for ELL1H shapiro delay. |
integer |
|
NTOA |
Number of TOAs used in the fitting |
integer |
|
OM |
Longitude of periastron |
deg |
|
OMDOT |
Rate of advance of periastron |
deg / yr |
|
ORBWAVEC{number} |
Coefficient of the 0th cosine wave in Fourier series model of Tasc variations |
number |
|
ORBWAVES{number} |
Coefficient of the 0th sine wave in Fourier series model of Tasc variations |
number |
|
ORBWAVE_EPOCH |
Reference epoch for ORBWAVEs model |
d |
|
ORBWAVE_OM |
Base frequency for ORBWAVEs model |
rad / s |
|
PB |
Orbital period |
d |
|
PBDOT |
Orbital period derivative respect to time |
number |
|
PEPOCH |
Reference epoch for spin-down |
d |
|
PHOFF |
Overall phase offset between physical TOAs and the TZR TOA. |
number |
|
PLANET_SHAPIRO |
Include planetary Shapiro delays |
boolean |
|
PMDEC |
Proper motion in DEC |
mas / yr |
|
PMELAT / PMBETA |
Proper motion in ecliptic latitude |
mas / yr |
|
PMELONG / PMLAMBDA |
Proper motion in ecliptic longitude |
mas / yr |
|
PMRA |
Proper motion in RA |
mas / yr |
|
POSEPOCH |
Reference epoch for position |
d |
|
PSR / PSRJ, PSRB |
Source name |
string |
|
PWEP_{number} |
(‘Epoch of solution piece 1’,) |
d |
|
PWF0_{number} |
Frequency of solution piece 1 |
Hz |
|
PWF1_{number} |
Frequency-derivative of solution piece 1 |
Hz / s |
|
PWF2_{number} |
Second frequency-derivative of solution piece 1 |
Hz / s2 |
|
PWPH_{number} |
(‘Starting phase of solution piece 1’,) |
number |
|
PWSTART_{number} |
(‘Start epoch of solution piece 1’,) |
d |
|
PWSTOP_{number} |
(‘Stop epoch of solution piece 1’,) |
d |
|
PX |
Parallax |
mas |
|
RAJ / RA |
Right ascension (J2000) |
hourangle |
|
RM |
Rotation measure |
rad / m2 |
|
RNAMP |
Amplitude of powerlaw red noise. |
number |
|
RNIDX |
Spectral index of powerlaw red noise. |
number |
|
SHAPMAX |
Function of inclination angle |
number |
|
SIFUNC |
Type of interpolation |
number |
|
SINI |
Sine of inclination angle |
number |
|
START |
Start MJD for fitting |
d |
|
STIGMA / VARSIGMA, STIG |
Shapiro delay parameter STIGMA as in Freire and Wex 2010 Eq(12) |
number |
|
SWEPOCH |
Epoch of NE_SW measurement |
d |
|
SWM |
Solar Wind Model (0 is from Edwards+ 2006, 1 is from You+2007,2012/Hazboun+ 2022) |
integer |
|
SWP |
Solar Wind Model radial power-law index (only for SWM=1) |
number |
|
SWXDM_{number} |
Max Solar Wind DM |
pc / cm3 |
|
SWXP_{number} |
Solar wind power-law index |
number |
|
SWXR1_{number} |
Beginning of SWX interval |
d |
|
SWXR2_{number} |
End of SWX interval |
d |
|
T0 |
Epoch of periastron passage |
d |
|
T0X_{number} |
ParameterT0variation |
d |
|
T2CMETHOD |
Method for transforming from terrestrial to celestial frame (IAU2000B/TEMPO; PINT only supports ????) |
string |
|
TASC |
Epoch of ascending node |
d |
|
TIMEEPH |
Time ephemeris to use for TDB conversion; for PINT, always FB90 |
string |
|
TNCHROMAMP |
Amplitude of powerlaw chromatic noise in tempo2 format |
number |
|
TNCHROMC |
Number of chromatic noise frequencies. |
number |
|
TNCHROMGAM |
Spectral index of powerlaw chromatic noise in tempo2 format |
number |
|
TNCHROMIDX |
Chromatic measure index |
number |
|
TNDMAMP |
Amplitude of powerlaw DM noise in tempo2 format |
number |
|
TNDMC |
Number of DM noise frequencies. |
number |
|
TNDMGAM |
Spectral index of powerlaw DM noise in tempo2 format |
number |
|
TNEQ {flag} {value} |
An error term added in quadrature to the scaled (by EFAC) TOA uncertainty in units of log10(second). |
dex(s) |
|
TNREDAMP |
Amplitude of powerlaw red noise in tempo2 format |
number |
|
TNREDC |
Number of red noise frequencies. |
number |
|
TNREDGAM |
Spectral index of powerlaw red noise in tempo2 format |
number |
|
TRACK |
Tracking Information |
string |
|
TRES |
TOA residual after fitting |
us |
|
TZRFRQ |
The frequency of the zero phase TOA. |
MHz |
|
TZRMJD |
Epoch of the zero phase TOA. |
d |
|
TZRSITE |
Observatory of the zero phase TOA. |
string |
|
UNITS |
Units (TDB assumed) |
string |
|
WAVEEPOCH |
Reference epoch for wave solution |
d |
|
WAVE_OM |
Base frequency of wave solution |
rad / d |
|
WAVE{number} |
Wave components |
s |
|
WXCOS_{number} |
Cosine amplitudes for Fourier representation of red noise |
s |
|
WXEPOCH |
Reference epoch for Fourier representation of red noise |
d |
|
WXFREQ_{number} |
Component frequency for Fourier representation of red noise |
1 / d |
|
WXSIN_{number} |
Sine amplitudes for Fourier representation of red noise |
s |
|
XOMDOT |
Excess longitude of periastron advance compared to GR |
deg / yr |
|
XPBDOT |
Excess Orbital period derivative respect to time compared to GR |
number |
|
XR1_{number} |
Beginning of paramX interval |
d |
|
XR2_{number} |
End of paramX interval |
d |
For comparison, there is a table of parameters that TEMPO supports.