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Current Results and Future Capabilities of Pulsar Timing. Andrea N. Lommen International Liaison for NANOGrav Associate Professor of Physics and Astronomy Head of Astronomy Program Director of Grundy Observatory Franklin and Marshall College Lancaster, PA.
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Current Results and Future Capabilities of Pulsar Timing Andrea N. Lommen International Liaison for NANOGrav Associate Professor of Physics and Astronomy Head of Astronomy Program Director of Grundy Observatory Franklin and Marshall College Lancaster, PA “Pulsar Timing: No longer a blunt instrument for gravitational Wave detection” Lommen, Journal of Physics, 2012
IPTA = NANOGrav + EPTA + PPTA • NANOGrav = North American Nanohertz Observatory of Gravitational Waves • EPTA = European Pulsar Timing Array • PPTA = Parkes Pulsar Timing Array (Australia)
The International Pulsar Timing Array www.ipta4gw.org
Photo Courtesy of Virgo Pulsar1 Pulsar2 Earth Adapted from NASA figure
NANOGrav Residuals Adapted from Demorest et al (2013) by David Nice
NANOGrav 5-year timing results summary Demorest et al (2013)
Orbital Motion in the Radio Galaxy 3C 66B: Evidence for a Supermassive Black Hole Binary Sudou, Iguchi, Murata, Taniguchi (2003) Science 300: 1263-1265. Constraining the Properties of Supermassive Black Hole Systems Using Pulsar Timing: Application to 3C 66b, Jenet, Lommen, Larson and Wen (2004) ApJ 606:799-803. (NANOGrav) 10 10 0 Residual(ms) 0 Residual(ms) -10 -10 Simulated residuals due to 3c66b Data from Kaspi, Taylor, Ryba 1994
Hellings and Downs Curve (Overlap Reduction Function) Courtesy of Rick Jenet (NANOGrav) and George Hobbs (PPTA). Original figure from Hellings and Downs (1983).
Lee et al. (2008) • Measure the polarisation properties of gravitational wave • Test theories of gravity…! (NANOGrav -> EPTA)
Sydney Chamberlin (UW Milwaukee, NANOGrav) Non-Einsteinian gravitational waves using PTAs Chamberlin et al, PhRvD (2012)
MBH-MBH (indiv) Gal NS/BH PSRs Figure by Paul Demorest, NANOGrav (see arXiv:0902.2968 and arXiv:1201.6641) BH-BH (indiv)
Method used from: Ellis, Siemens, and Creighton ApJ 2012. Plot courtesy of Xavi Siemens. (NANOGrav) Similar to work of Yardley et al (2011, PPTA) but about a factor of 7 more sensitive
Ability to constrain position is function of h Kejia Lee (EPTA) et al, 2011, MNRAS
From Sesana & Vecchio (2010), EPTA Source amp Sky position phase frequency Polarization angle Inclination angle 100 pulsars, SNR=10
A 5 x 109 solar-mass black hole binary coalescing 100 Mpc away. 30 IPTA pulsars, improved by 10, sampled once a day. From Finn & Lommen 2010 (NANOGrav) Thank you to Manuela Campanelli, Carlos O. Lousto, Hiroyuki Nakano, and YosefZlochower for waveforms. Phys.Rev.D79:084010 (2009). http://ccrg.rit.edu/downloads/waveforms
Measuring the graviton mass Kejia Lee et al (2010), EPTA
Cosmic String Tension Upper Limits • SotiriosSanidas, Richard Battye, and Ben Stappers (U of Manchester and Jodrell Bank Center for Astrophysics, EPTA) 2011
Measuring spin-orbit precession of BHBs using pulsar timing by Mingarelli et al, PhRvL (2012) Trevor Sidery, Kat Grover, Rory Smith, ChiaraMingarelli.
Deng & Finn (NANOGrav, 2011) curvature of the waveform • Pitkin & Woan (2012) a clever use of the “pulsar term” to increase the possibility of detecting a burst signal. (LIGO!)
The GW sky is not isotropic in the PTA band!(JoeSimon, Franklin and Marshall College, NANOGrav, in prep) • Should we expect nHz gravitational-wave hotspots?
A Large European Array for Pulsars = LEAP! Coherently add pulsar observations from 5 of the largest telescopes in Europe (and the world!) to obtain most precise TOA’s for GW detection. Combine telescopes to form a phased array, a telescope with equivalent size of a 200 m dish - ~5% SKA! A LEAP in collecting area. Funded by European Research Council Advanced Grant (PI Kramer).
Five-hundred-meter Aperture Spherical radio Telescope (FAST) • Unique Karst depression as the site • Active main reflector • Cable - parallel robot feed support 100 米 500 米 300 米 30
GW-sensitivity IPTA IPTA+FAST
We need & want people to join us • Lots of data, low on people-power • $6.5M grant from NSF -> NANOGrav to foster international collaboration. • Student and faculty exchanges.
The Pulsar Data Challenge • Opened a week ago (March 23) • Will close in Sept • Go to www.ipta4gw.org
Summary • Pulsars make a galactic scale gravitational wave observatory which is poised to detect gravitational waves in 5-10 years. • Stochastic, single sources, alternate polarizations, waveform and location recovery, mass of the graviton, spin-orbit coupling, cosmic strings… • Coopetition works even though it’s not a real word • Please get involved, through data challenges is one way, student and faculty exchanges another • We expect to be surprised.