How to use TEMPO2

1、tempo2 tutorial george hobbs (饺饺子子), research scientist csiro australia telescope national facility, international young scientist of ntsc george.hobbscsiro.au content tempo2 is a software package. it implements “pulsar timing” algorithms. section 1: what tempo2 has been used for. overview of tempo2

2、 section 2: how to use tempo2 section 3: how to develop tempo2 major tempo2 developers (software and algorithms): g. hobbs, r. edwards, r. manchester, w. coles, x. you, m. keith, f. jenet, d. yardley, j. verbiest, csiro. tempo2 what has tempo2 been used for in 2010/2011? searching for gravitational

3、wave signals (e.g., yardley et al. 2011, yardley et al. 2010, abbott et al. 2010, van haasteren et al. 2010) using pulsars as navigational aids (ruggiero 2011) statistical analysis of timing residuals (e.g., na, x. s. et al., 2011, hobbs et al. 2010) studying emission geometry (e.g., noutsos et al.,

4、 2011) searching for gamma-ray pulsars (ray et al., 2010) determining pulsar masses (demorest et al. 2010) studying pulsations from main-sequence stars (ravi et al. 2010) tests of relativity (weisberg et al. 2010) measuring jupiters mass (champion et al. 2010) observations of glitches (chukwude et a

5、l. 2010) analysis of accreting millisecond x-ray pulsar (patruno et al. 2010) relativistic spin precession (manchester et al. 2010) csiro. tempo2 what does tempo2 do? usage 1: start with file of pulse arrival times start with model of a pulsars spin, astrometric and orbital parameters - pulsar timin

6、g residuals usage 2: start with pulsar timing model - predict the pulse phase and frequency at a given observatory at a given time csiro. tempo2 a parameter file (.par) csiro. tempo2 pulsar name, astrometric, rotational, dispersion measure and orbital parameters realisation of terrestrial time solar

7、 system ephemeris weighted fit? fit for this parameter? an arrival time file (.tim) csiro. tempo2 states that this is a tempo2 format file filename or identifier observing frequency (mhz) site arrival time (mjd) uncertainty on arrival time (us) telescope code user defined flags how does tempo2 work?

8、 the algorithms are based on those implemented in tempo1 details in hobbs, edwards & manchester (2006) and edwards, hobbs & manchester (2006) csiro. tempo2 conversion of site-arrival- time to pulse emission time clock corrections atmospheric delays einstein delay shapiro delay roemer delay secular m

9、otion (e.g., radial velocity) dispersive delay orbital motion details: clock correction must convert from the observatory time standard to a realisation of terrestrial time tt. use set of text files containing the difference between two time standards: pks2gps.clk, gps2utc.clk, utc2tai.clk, tai2tt_b

10、ipm2011. csiro. tempo2 youll find these files in $tempo2/clock directory details: einstein delay pulse arrival times (in terrestrial time) must be converted to the frame of the solar system barycentre. tempo2 uses the tabulated results of irwin & fukushima (1999) csiro. tempo2 details: roemer delay

11、the roemer delay is the vacuum light travel time between the pulse arriving at the observatory and the equivalent arrival time at the ssb. csiro. tempo2 r k r k ssb earth pulsar k = unit vector pointing at pulsar. obtained from ra, dec, pmra, pmdec r is vector from observatory to ssb. use jpl epheme

12、ris, observatory coordinates and earth orientation parameters use observatory coordinate file to know position of observatory roemer delay csiro. gravitational wave detection pulsar in ecliptic ecliptic latitude = 90 deg details: shapiro delay time delay caused by the passage of the pulse through la

13、rge gravitational fields. tempo2 includes delay caused by sun ( 110us), jupiter (180ns), saturn (58ns), neptune (12ns) and uranus ( ptrue pulsar timing residuals: incorrect f1 csiro. tempo2 pmodel ptrue pulsar timing residuals: incorrect position csiro. tempo2 pulsar timing residuals: incorrect prop

14、er motion csiro. tempo2 pulsar timing residuals csiro. tempo2 good parameters do not have a phase connected solution phase wraps induced timing residuals from ism and from gravitational waves csiro. tempo2 50cm (600mhz) 20cm (1400mhz) 10cm (3000mhz) induced residuals from gravitational wave backgrou

15、nd incorrect conversion to pulsar frame csiro. tempo2 champion et al. (2010): induced timing residuals from error in mass of jupiter of 5x10-10 mo predictive mode tempo2 can provide a polynomial approximation of the phase and pulse frequency at the observatory for a specified time interval. tempo1 c

16、reates polycos. tempo2 can create polycos, but we recommend predictors. predictors model the phase as a function of time using chebyshev polynomials. tempo2 provides a c library to read predictors tempo2 f mypar.par pred sitename mjd1 mjd2 freq1 freq2 ntimecoeff nfreqcoeff seg_length csiro. tempo2 o

17、bserving frequency range (mhz) time range segment length (s) part 2 usage of tempo2 and example of pulsar timing tempo2 is written in c/c+ (with a little fortran) and runs on linux and macos. main tempo2 website: http:/www.atnf.csiro.au/research/pulsar/tempo2 (see “tutorials” and “documentation”) ma

18、in tempo2 download site: http:/ tempo2 email distribution list: sign up at http:/ (click on “mailing lists”) contact: george.hobbscsiro.au, use feedback form csiro. tempo2 running tempo2 need a pulsar model (use the atnf pulsar catalogue http:/www.atnf.csiro.au/research/pulsar/psrcat - type in pulsa

19、r name and click get ephemeris) get some pulse arrival times (use parkes data archive see jonathans talk and pat in psrchive see willems talk) tempo2 f psrname.par psrname.tim csiro. tempo2 using the “plk” graphical interface tempo2 gr plk f mypar.par mytim.tim csiro. tempo2 which parameters to fit

20、re-do the fit what to plot the residuals press h to get help other useful graphical interfaces: spectrum csiro. tempo2 other useful graphical interfaces: plotmany csiro. tempo2 tempo2 gr plotmany f par1.par tim1.tim f par2.par tim2.tim f par3.par par3.tim the glitch plugin csiro. tempo2 yu meng (in

21、preparation) glitch events pulse frequency pulse frequency with mean removed pulse frequency derivative using “output” interfaces tempo2 output general s “hello f0 = f0_v f0_en f1 = f1_v f1_en” f mypar.par mytim.tim tempo2 output general2 s “freq = freq, sat = sat, bat = bat, res = pren” f mypar.par

22、 mytim.tim tempo2 output matrix f mypar.par mytim.tim csiro. tempo2 part 3: developing the software you should never need to modify the main tempo2 source code. (please report any bugs to george.hobbscsiro.au) you should create new “plug-in packages”. these can be for text output, a graphical interf

23、ace, methods to select data or new fitting algorithms. csiro. tempo2 creating a new text output format print out the pulsar model parameters and the timing residuals in your format csiro. tempo2 must include tempo2.h must have this function pulsar number parameter of interest time derivative observa

24、tion number observation parameter number of observations creating a new graphical interface csiro. tempo2 must include this function must process the command line arguments read parameter and observation file(s) form barycentric arrival times, residuals and fit. repeat with post- fit parameters do y

25、our plotting/analysis etc. must define how many pulsars to process output format versus graphical interface output format: tempo2 runs as usual then gives control to your plugin to display the output (easy, but no control over fitting etc.) graphical interface: tempo2 provides control to your plugin

26、 from the beginning (your plugin must call all the functions to read data files, do the fit etc., but you have more control) csiro. tempo2 the tempo2 toolkits to aid development the following toolkits are available: t2toolkit.h: find minimum and maximum values in array, find rms, mean, range, sort d

27、ata array, create random numbers tkspectrum.h: routines for spectral estimation tkfit.h: fitting routines (e.g., svd, cholesky decomposition ) tempo2util.h: calculate dot products, turns hh:mm:ss/dd:mm:ss into degrees gwsim.h: gravitational wave simulation routines. (note: many people use “numerical

28、 recipes” routines in plugins these are copyright and the source code cannot be made publically available use the tempo2 toolkits instead) csiro. tempo2 debugging your installation sometimes things dont work! if it doesnt compile: check that your version of gfortran, gcc and g+ are the same! check t

29、hat pgplot has been correctly installed. it compiles and runs, but doesnt do anything: run your code with tempo2 . f mypar.par mytim.tim debug displayversion outfile and then send your .par, .tim and outfile to george.hobbscsiro.au (or any tempo2 developer) your plugin does not work. check that you

30、have installed the plugin in $tempo2/plugins/ csiro. tempo2 publishing results from tempo2 for general usage, please cite: hobbs, edwards & manchester (2006) for details of the algorithms: edwards, hobbs & manchester (2006) for gravitational wave implementation: hobbs et al. (2009) to enable complet

31、e reproducibility of results should include an appendix including output of displayversion. important: publish the clock reference (e.g., tt(tai) and solar system ephemeris model (e.g., de405) csiro. tempo2 topics not covered in this presentation simulating data (use fake, gwbkgrd plugins) use of flags (use select, -pass, -filter options) atmospheric corrections xiaopengs solar wind model fermi gamma-ray plugin use of fitfunc and splug interfaces use of region files measuring dispersion measur