pulsar timing at parkes

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Pulsar Timing at Parkes. George Hobbs CSIRO Australia Telescope National Facility george.hobbs@csiro.au. Purpose of talk. Highlight some recent results relating to pulsar timing and the Parkes Observatory Time constraints => will mainly concentrate on work that Ive been involved in. - PowerPoint PPT Presentation

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pulsar timing

Pulsar Timing at ParkesGeorge HobbsCSIRO Australia Telescope National Facilitygeorge.hobbs@csiro.au

1Purpose of talkHighlight some recent results relating to pulsar timing and the Parkes ObservatoryTime constraints => will mainly concentrate on work that Ive been involved in

CSIRO. Gravitational wave detectionLarge number of collaborators including: CASS pulsar group, PPTA team, Chinese pulsar community .CSIRO. Gravitational wave detectionTOA (measured using the observatory clock)ResidualPulsar timingFoldFoldModelSlide from D. Champion

3CSIRO. Gravitational wave detectionA few simulationsWith one pulsar you cannot (normally) tell what unmodelled physical effect is causing the residuals

GW background

Spin-down irregularities

Clock noiseSimulated data4CSIRO. Gravitational wave detectionSpin-down irregularities

No angular signature

5CSIRO. Gravitational wave detectionTerrestrial time standard irregularities

Monopolar signature6CSIRO. Gravitational wave detectionErrors in the planetary ephemerides - e.g. error in the mass of Jupiter

Dipolar signature7CSIRO. Gravitational wave detectionWhat if gravitational waves exist?

Quadrapolar signature8With enough pulsars these different effects can be separatedStudying individual pulsars using Parkes dataM. Yu et al. (in preparation) detection of 105 glitches in 36 pulsars observed at ParkesX. You et al. (in preparation) analysis of the Solar Wind magnetic field and electron density using PPTA observations of J1022+1001Manchester et al. (2010) relativistic spin precession in PSR J1141-6545Weltevrede et al. (2010) Pulsar timing for the Fermi missionVerbiest et al. (2008) - Limits on the variation of the gravitational constant You et al. (2007) - Studies of the interstellar medium.

- concentrate in this talk on looking for correlations between timing residuals .CSIRO. Gravitational wave detectionDeveloping a pulsar-based time standardParkes data + AreciboCSIRO. Gravitational wave detection

Pulsar time standard w.r.t TT(TAI)Best time standard w.r.t. TT(TAI)Measuring planetary massesUse International Pulsar Timing Array data from Parkes, Effelsberg, Nancay and Arecibo.Champion et al. 2010, ApJ.A planetary mass error will lead to incorrect determination of the Solar System barycentre => correlated pulsar timing residualsCan fit to multiple pulsars simultaneously to search for such a signalCSIRO. Gravitational wave detection

CSIRO. Gravitational wave detectionMeasuring planetary massChampion, Hobbs, Manchester et al. (2010), ApJ, 720, 201Use data from Parkes, Arecibo, Effelsberg and Nancay

MSunBest PublishedThis workMercury1.66013(7)x10-71.660(2)x10-7Venus2.4478686(4)x10-62.44782(10)x10-6Mars3.227151(9)x10-73.2277(8)x10-7Jupiter*9.547919(8)x10-49.547916(4)x10-4Saturn2.85885670(8)x10-42.858858(14)x10-49.54791915(11)x10-4

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Published limits on gravitational wave background (95% confidence)CSIRO. Gravitational wave detectionAll use the same Kaspi et al. (1994) data setTentative new boundPoor choice of pulsar?Incorrect algorithm?Use same data setPulsar navigation: assume that you are on the Earths surfacePULSE@Parkes observationsCSIRO. Gravitational wave detection

Pulsar navigation: assume that you are on the Earths surfaceParkes observationsCSIRO. Gravitational wave detection

Pulsar navigation: assume that you are on the Earths surfaceParkes observationsCSIRO. Gravitational wave detection

Pulsar navigation: assume that you are on the Earths surfaceParkes observationsCSIRO. Gravitational wave detection

Pulsar navigation: assume that you are on the Earths surfaceParkes observations correct to within a few kilometresCSIRO. Gravitational wave detection

Pulsar navigation: in 3DCSIRO. Gravitational wave detection

ConclusionCan distinguish between many phenomena by looking for correlated timing residuals between pulsarsHave improved understanding of individual pulsarsHave developed a pulsar-based time standardHave the most precise, published, mass estimate for the Jovian systemHave not detected gravitational waves, but getting closerCan reverse the timing procedure to determine our position.CSIRO. Gravitational wave detection28fa19dfb0 rpl-wlan20

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