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Title: THE DISTURBANCE OF A MILLISECOND PULSAR MAGNETOSPHERE

Abstract

Pulsar timing has enabled some of the strongest tests of fundamental physics. Central to the technique is the assumption that the detected radio pulses can be used to accurately measure the rotation of the pulsar. Here, we report on a broadband variation in the pulse profile of the millisecond pulsar J1643−1224. A new component of emission suddenly appears in the pulse profile, decays over four months, and results in a permanently modified pulse shape. Profile variations such as these may be the origin of timing noise observed in other millisecond pulsars. The sensitivity of pulsar-timing observations to gravitational radiation can be increased by accounting for this variability.

Authors:
; ; ; ; ; ;  [1];  [2]; ; ; ;  [3];  [4];  [5];  [6];  [7]; ;  [8];  [9];  [10] more »; « less
  1. CSIRO Astronomy and Space Science, Australia Telescope National Facility, Box 76, Epping, NSW 1710 (Australia)
  2. Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)
  3. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 3122 (Australia)
  4. International Centre for Radio Astronomy Research, Curtin University, Bentley, WA 6102 (Australia)
  5. Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA 92093 (United States)
  6. CSIRO Information Management and Technology, Box 225, Dickson, ACT 2602 (Australia)
  7. Jodrell Bank Centre for Astrophysics, University of Manchester, M13 9PL (United Kingdom)
  8. Monash Centre for Astrophysics, School of Physics and Astronomy, Monash University, VIC 3800 (Australia)
  9. Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States)
  10. Department of Physics, University of Wisconsin-Milwaukee, Box 413, Milwaukee, WI 53201 (United States)
Publication Date:
OSTI Identifier:
22654235
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 828; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCOUNTING; DECAY; DISTURBANCES; EMISSION; GRAVITATIONAL RADIATION; PULSARS; PULSE SHAPERS; PULSES; ROTATION; SENSITIVITY; STARS

Citation Formats

Shannon, R. M., Kerr, M., Dai, S., Hobbs, G., Manchester, R. N., Reardon, D. J., Toomey, L., Lentati, L. T., Bailes, M., Osłowski, S., Rosado, P. A., Van Straten, W., Bhat, N. D. R., Coles, W. A., Dempsey, J., Keith, M. J., Lasky, P. D., Levin, Y., Ravi, V., Spiewak, R., E-mail: ryan.shannon@csiro.au, and and others. THE DISTURBANCE OF A MILLISECOND PULSAR MAGNETOSPHERE. United States: N. p., 2016. Web. doi:10.3847/2041-8205/828/1/L1.
Shannon, R. M., Kerr, M., Dai, S., Hobbs, G., Manchester, R. N., Reardon, D. J., Toomey, L., Lentati, L. T., Bailes, M., Osłowski, S., Rosado, P. A., Van Straten, W., Bhat, N. D. R., Coles, W. A., Dempsey, J., Keith, M. J., Lasky, P. D., Levin, Y., Ravi, V., Spiewak, R., E-mail: ryan.shannon@csiro.au, & and others. THE DISTURBANCE OF A MILLISECOND PULSAR MAGNETOSPHERE. United States. doi:10.3847/2041-8205/828/1/L1.
Shannon, R. M., Kerr, M., Dai, S., Hobbs, G., Manchester, R. N., Reardon, D. J., Toomey, L., Lentati, L. T., Bailes, M., Osłowski, S., Rosado, P. A., Van Straten, W., Bhat, N. D. R., Coles, W. A., Dempsey, J., Keith, M. J., Lasky, P. D., Levin, Y., Ravi, V., Spiewak, R., E-mail: ryan.shannon@csiro.au, and and others. 2016. "THE DISTURBANCE OF A MILLISECOND PULSAR MAGNETOSPHERE". United States. doi:10.3847/2041-8205/828/1/L1.
@article{osti_22654235,
title = {THE DISTURBANCE OF A MILLISECOND PULSAR MAGNETOSPHERE},
author = {Shannon, R. M. and Kerr, M. and Dai, S. and Hobbs, G. and Manchester, R. N. and Reardon, D. J. and Toomey, L. and Lentati, L. T. and Bailes, M. and Osłowski, S. and Rosado, P. A. and Van Straten, W. and Bhat, N. D. R. and Coles, W. A. and Dempsey, J. and Keith, M. J. and Lasky, P. D. and Levin, Y. and Ravi, V. and Spiewak, R., E-mail: ryan.shannon@csiro.au and and others},
abstractNote = {Pulsar timing has enabled some of the strongest tests of fundamental physics. Central to the technique is the assumption that the detected radio pulses can be used to accurately measure the rotation of the pulsar. Here, we report on a broadband variation in the pulse profile of the millisecond pulsar J1643−1224. A new component of emission suddenly appears in the pulse profile, decays over four months, and results in a permanently modified pulse shape. Profile variations such as these may be the origin of timing noise observed in other millisecond pulsars. The sensitivity of pulsar-timing observations to gravitational radiation can be increased by accounting for this variability.},
doi = {10.3847/2041-8205/828/1/L1},
journal = {Astrophysical Journal Letters},
number = 1,
volume = 828,
place = {United States},
year = 2016,
month = 9
}
  • The millisecond pulsar (MSP) J1903+0327 is accompanied by an ordinary G dwarf star in an unusually wide (P{sub orb} {approx_equal} 95.2 days) and eccentric (e {approx_equal} 0.44) orbit. The standard model for producing MSPs fails to explain the orbital characteristics of this extraordinary binary, and alternative binary models are unable to explain the observables. We present a triple-star model for producing MSPs in relatively wide eccentric binaries with a normal (main-sequence) stellar companion. We start from a stable triple system consisting of a low-mass X-ray binary (LMXB) with an orbital period of at least 1 day, accompanied by a Gmore » dwarf in a wide and possibly eccentric orbit. Variations in the initial conditions naturally provide a satisfactory explanation for the unexplained triple component in the eclipsing soft X-ray transient 4U 2129+47 or the cataclysmic variable EC 19314-5915. The best explanation for J1903+0327, however, results from the expansion of the orbit of the LMXB, driven by the mass transfer from the evolving donor star to its neutron star companion, which causes the triple eventually to become dynamically unstable. Using numerical computations we show that, depending on the precise system configuration at the moment the triple becomes dynamically unstable, the ejection of each of the three components is possible. If the donor star of the LMXB is ejected, a system resembling J1903+0327 will result. If the neutron star is ejected, a single MSP results. This model therefore also provides a straightforward mechanism for forming a single MSP in the Galactic disk. We conclude that the Galaxy contains some 30-300 binaries with characteristics similar to J1903+0327 and about an order of magnitude fewer single MSPs produced with the proposed triple scenario.« less
  • Astrometric interferometer observations of PSR 1937 + 21 and PSR 1913 + 16 were made at the VLA in the FK4 B1950.0 reference frame with positional accuracy of + or - 0.05 arcsec and + or - 0.15 arcsec, respectively. After removing the E terms of aberration, these positions are compared with ones obtained from pulse-timing observations, which are accurate to + or - 0.001 arcsec and + or - 0.003 arcsec, respectively, in the reference frame of solar system ephemerides. The timing position of PSR 1937 + 21 agrees to within 0.07 arcsec (1.3 sigma) of the VLA position;more » comparison of the same observations in the J2000.0 reference frame reduces the discrepancy to 0.01 arcsec. The result for PSR 1913 + 16 strengthens the conclusion of Elliot et al. (1980) that a faint star near the pulsar is not the orbiting companion. 26 references.« less
  • We present X-ray observations of the 'redback' eclipsing radio millisecond pulsar (MSP) and candidate radio pulsar/X-ray binary transition object PSR J1723-2837. The X-ray emission from the system is predominantly non-thermal and exhibits pronounced variability as a function of orbital phase, with a factor of ∼2 reduction in brightness around superior conjunction. Such temporal behavior appears to be a defining characteristic of this variety of peculiar MSP binaries and is likely caused by a partial geometric occultation by the main-sequence-like companion of a shock within the binary. There is no indication of diffuse X-ray emission from a bow shock or pulsarmore » wind nebula associated with the pulsar. We also report on a search for point source emission and γ-ray pulsations in Fermi Large Area Telescope data using a likelihood analysis and photon probability weighting. Although PSR J1723-2837 is consistent with being a γ-ray point source, due to the strong Galactic diffuse emission at its position a definitive association cannot be established. No statistically significant pulsations or modulation at the orbital period are detected. For a presumed detection, the implied γ-ray luminosity is ≲5% of its spin-down power. This indicates that PSR J1723-2837 is either one of the least efficient γ-ray producing MSPs or, if the detection is spurious, the γ-ray emission pattern is not directed toward us.« less
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