timing 致密天体与弥漫介质研究团组（PPT43）课件.ppt

Pulsar timing residuals: incorrect F1 CSIRO. TEMPO2 Pmodel Ptrue Pmodel Ptrue Pulsar timing residuals: incorrect position CSIRO. TEMPO2 Pulsar timing residuals: incorrect proper 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 background 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 creates 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 Observing 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”) Main tempo2 download site: /projects/tempo2 Tempo2 email distribution list: Sign up at (click on “Mailing Lists”) Contact: george.hobbs@csiro.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 pulsar name and click ‘Get Ephemeris’) Get some pulse arrival times (use Parkes data archive – see Jonathan’s talk and ‘pat’ in psrchive – see Willem’s talk) tempo2 –f psrname.par psrname.tim CSIRO. TEMPO2 Using the “plk” graphical interface tempo2 –gr plk –f mypar.par mytim.tim CSIRO. TEMPO