Using Tempo to calculate solar barycentric time Dejan Paradiž University of Ljubljana

Tempo general Autors: Autors: J. H. Taylor, R. N. Manchester, D. J. Nice, J. M. Weisberg, A. Irwin, N. Wex and others. Ephemeris routines by E. M. Standish, NASA/JPL. Standard mode allows: Standard mode allows : Fitting pulse time of arrivals (TOAs) to pulsar timing model including time transformation to solar system barycentre. It includes modeling of pulsar rotation spin down and the possibility of several binary models. Prediction mode: Prediction mode : Calculates ephemerides of pulsar phase behavior for specified pulsar model. Calculates ephemerides of pulsar phase behavior for specified pulsar model.

Pulsar model parameters Important parameters: RA Right Ascension DEC Declination PMRA Proper motion in RA [mas/year] PMDEC Proper motion in Declination [mas/year] PMRV Radial 'proper motion [mas/year]' PX Parallax [mas] PEPOCH Epoch of frequency /period parameters and position F / P Pulsar rotation frequency [Hz ] / periodor [s] F1/P1 Pulsar rotation frequency [Hz -2 ] /period derivative [s ] F2 Pulsar rotation frequency second derivative [Hz -3 ] Fn Pulsar rotation frequency n'th derivative [Hz -(n+1) ] DM Dispersion measure [pc cm -3 ] ephemerides Absolute reference for the ephemerides : TZRMJD Reference TOA [day] TZRFREQ Frequency of reference TOA [MHz] TZRSITE One-letter observatory code of reference TOA

Prediction mode Input parameters (tz.in): Default settings ASITE a one-character site code MAXHADEF maximum hour angle [h] NSPANDEF time span [min] NCOEFFDEF number of coefficients FREQDEF observing frequency [MHz] Settings for individual pulsar: NAME pulsar name NSPAN time span [min] NCOEFF number of coefficients MAXHA maximum hour angle [h] FREQ observing frequency [MHz] Example of tz.in file. Pulsar model: Pulsar parameters are stored in files '.par' which are located in the 'PARDIR' directory, specified in tempo.cfg file. Crab parameters for prediction mode..

The polynomial ephemerides are written to file 'polyco.dat'. Prediction mode Example of polyco.dat for Crab pulsar. Change of Crab frequency over the year. Pulsar name Date (day-month-year) Time (hhmmss) TMID [MJD] Dispersion measure Doppler's shift due to earth motion [10 -4 ]Log_10 of fit rms residual in periods Reference phase (RPHASE) Referenc frequency F0 [Hz] Observatory number Nspan [min] Number of coefficients Binary phaseCoefficients DT = (T-TMID)*1440 PHASE = RPHASE + DT*60*F0 + COEFF(1) + DT*COEFF(2) + DT^2*COEFF(3) FREQ(Hz) = F0 + (1/60)*(COEFF(2) + 2*DT*COEFF(3) + 3*DT^2*COEFF(4) +....) Change of Crab frequency over two days.

Header control cards: CLK Terrestrial time standard EPHEM Solar system ephemeris NITS Iterate solution n times, or fewer if it converges. PSR Pulsar name BINARY Binary model to use START Ignore TOAs before this date FINISH Ignore TOAs after this date NTOA Number of TOA lines TRES Time resolution Standard mode Example of header file provided with Tempo package. Header control cards and pulsar parameters are stored in file '.par' or they can be combined whith TOA lines into single file.

TOAs are entered, one per line, in one of three formats, called 'Princeton', 'Parkes', and 'Interchange TOA (ITOA)' format. Standard mode DITHER x Add Gaussian noise with rms=x μs. EMIN x Set minimum uncertainty to x JUMP Beginning or end of a jump segment SIGMA x Set uncertainties of following TOAs to x μs (forces MODE=1)‏ Section of TOA lines in 'Parkers' which shows use of JUMP command. SIMEnter simulation mode SKIPSkip all lines until NOSKIP is read TIME xAdd x (seconds) to following TOAs TOA commands :

Output of standard mode includes files: - resid2.tmp is binary format in which each record contains eight real*8 values. -matrix.tmp includes covariance matrix. It is in binary format whith variable length records. -itoa.out is ASCII file in ITOA format whit corrected TOAs. (optional) Standard mode Example number of TOAs verses MJD of TOAs. Diference between input time of TOAs and corrected time.

Intruduction: Tempo2 is new version of tempo. Curently only beta version is available on addres below. What is new: - Designed for high precision pulsar timing experiments. - Allows to analyze the pulse arrival times for multiple pulsars simultaneously. - Graphical interface. Tempo2 Tempo2 graphical interface. ( /