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Title: Einstein@Home DISCOVERY OF A PALFA MILLISECOND PULSAR IN AN ECCENTRIC BINARY ORBIT

Abstract

We report the discovery of the millisecond pulsar (MSP) PSR J1950+2414 (P = 4.3 ms) in a binary system with an eccentric (e = 0.08) 22 day orbit in Pulsar Arecibo L-band Feed Array survey observations with the Arecibo telescope. Its companion star has a median mass of 0.3 M{sub ⊙} and is most likely a white dwarf (WD). Fully recycled MSPs like this one are thought to be old neutron stars spun-up by mass transfer from a companion star. This process should circularize the orbit, as is observed for the vast majority of binary MSPs, which predominantly have orbital eccentricities e < 0.001. However, four recently discovered binary MSPs have orbits with 0. 027 < e < 0.44; PSR J1950+2414 is the fifth such system to be discovered. The upper limits for its intrinsic spin period derivative and inferred surface magnetic field strength are comparable to those of the general MSP population. The large eccentricities are incompatible with the predictions of the standard recycling scenario: something unusual happened during their evolution. Proposed scenarios are (a) initial evolution of the pulsar in a triple system which became dynamically unstable, (b) origin in an exchange encounter in an environment with highmore » stellar density, (c) rotationally delayed accretion-induced collapse of a super-Chandrasekhar WD, and (d) dynamical interaction of the binary with a circumbinary disk. We compare the properties of all five known eccentric MSPs with the predictions of these formation channels. Future measurements of the masses and proper motion might allow us to firmly exclude some of the proposed formation scenarios.« less

Authors:
;  [1]; ;  [2]; ;  [3]; ; ; ;  [4]; ;  [5]; ; ;  [6];  [7];  [8];  [9];  [10];  [11] more »; « less
  1. Leibniz Universität, Hannover, D-30167 Hannover (Germany)
  2. Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL (United Kingdom)
  3. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)
  4. Max-Planck-Institut für Gravitationsphysik, Callinstr. 38, D-30167 Hannover (Germany)
  5. Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States)
  6. Department of Astronomy and Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (United States)
  7. Department of Physics and Astronomy, West Virginia University, Morgantown, WV 26506 (United States)
  8. Department of Physics and Astronomy, Franklin and Marshall College, Lancaster, PA 17604-3003 (United States)
  9. National Research Council, resident at the Naval Research Laboratory, Washington, DC 20375 (United States)
  10. Department of Physics, McGill University, Montreal, QC H3A 2T8 (Canada)
  11. ASTRON, Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA, Dwingeloo (Netherlands)
Publication Date:
OSTI Identifier:
22522295
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 806; 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; BINARY STARS; COMPARATIVE EVALUATIONS; DATA ANALYSIS; DENSITY; MAGNETIC FIELDS; MASS TRANSFER; NEUTRON STARS; ORBITS; PROPER MOTION; PULSARS; SPIN; STAR EVOLUTION; SURFACES; TELESCOPES; WHITE DWARF STARS

Citation Formats

Knispel, B., Allen, B., Lyne, A. G., Stappers, B. W., Freire, P. C. C., Lazarus, P., Aulbert, C., Bock, O., Eggenstein, H.-B., Fehrmann, H., Bogdanov, S., Camilo, F., Brazier, A., Chatterjee, S., Cordes, J. M., Cardoso, F., Crawford, F., Deneva, J. S., Ferdman, R., Hessels, J. W. T., E-mail: benjamin.knispel@aei.mpg.de, and and others. Einstein@Home DISCOVERY OF A PALFA MILLISECOND PULSAR IN AN ECCENTRIC BINARY ORBIT. United States: N. p., 2015. Web. doi:10.1088/0004-637X/806/1/140.
Knispel, B., Allen, B., Lyne, A. G., Stappers, B. W., Freire, P. C. C., Lazarus, P., Aulbert, C., Bock, O., Eggenstein, H.-B., Fehrmann, H., Bogdanov, S., Camilo, F., Brazier, A., Chatterjee, S., Cordes, J. M., Cardoso, F., Crawford, F., Deneva, J. S., Ferdman, R., Hessels, J. W. T., E-mail: benjamin.knispel@aei.mpg.de, & and others. Einstein@Home DISCOVERY OF A PALFA MILLISECOND PULSAR IN AN ECCENTRIC BINARY ORBIT. United States. doi:10.1088/0004-637X/806/1/140.
Knispel, B., Allen, B., Lyne, A. G., Stappers, B. W., Freire, P. C. C., Lazarus, P., Aulbert, C., Bock, O., Eggenstein, H.-B., Fehrmann, H., Bogdanov, S., Camilo, F., Brazier, A., Chatterjee, S., Cordes, J. M., Cardoso, F., Crawford, F., Deneva, J. S., Ferdman, R., Hessels, J. W. T., E-mail: benjamin.knispel@aei.mpg.de, and and others. 2015. "Einstein@Home DISCOVERY OF A PALFA MILLISECOND PULSAR IN AN ECCENTRIC BINARY ORBIT". United States. doi:10.1088/0004-637X/806/1/140.
@article{osti_22522295,
title = {Einstein@Home DISCOVERY OF A PALFA MILLISECOND PULSAR IN AN ECCENTRIC BINARY ORBIT},
author = {Knispel, B. and Allen, B. and Lyne, A. G. and Stappers, B. W. and Freire, P. C. C. and Lazarus, P. and Aulbert, C. and Bock, O. and Eggenstein, H.-B. and Fehrmann, H. and Bogdanov, S. and Camilo, F. and Brazier, A. and Chatterjee, S. and Cordes, J. M. and Cardoso, F. and Crawford, F. and Deneva, J. S. and Ferdman, R. and Hessels, J. W. T., E-mail: benjamin.knispel@aei.mpg.de and and others},
abstractNote = {We report the discovery of the millisecond pulsar (MSP) PSR J1950+2414 (P = 4.3 ms) in a binary system with an eccentric (e = 0.08) 22 day orbit in Pulsar Arecibo L-band Feed Array survey observations with the Arecibo telescope. Its companion star has a median mass of 0.3 M{sub ⊙} and is most likely a white dwarf (WD). Fully recycled MSPs like this one are thought to be old neutron stars spun-up by mass transfer from a companion star. This process should circularize the orbit, as is observed for the vast majority of binary MSPs, which predominantly have orbital eccentricities e < 0.001. However, four recently discovered binary MSPs have orbits with 0. 027 < e < 0.44; PSR J1950+2414 is the fifth such system to be discovered. The upper limits for its intrinsic spin period derivative and inferred surface magnetic field strength are comparable to those of the general MSP population. The large eccentricities are incompatible with the predictions of the standard recycling scenario: something unusual happened during their evolution. Proposed scenarios are (a) initial evolution of the pulsar in a triple system which became dynamically unstable, (b) origin in an exchange encounter in an environment with high stellar density, (c) rotationally delayed accretion-induced collapse of a super-Chandrasekhar WD, and (d) dynamical interaction of the binary with a circumbinary disk. We compare the properties of all five known eccentric MSPs with the predictions of these formation channels. Future measurements of the masses and proper motion might allow us to firmly exclude some of the proposed formation scenarios.},
doi = {10.1088/0004-637X/806/1/140},
journal = {Astrophysical Journal},
number = 1,
volume = 806,
place = {United States},
year = 2015,
month = 6
}
  • We report the discovery of the 20.7 ms binary pulsar J1952+2630, made using the distributed computing project Einstein-Home in Pulsar ALFA survey observations with the Arecibo telescope. Follow-up observations with the Arecibo telescope confirm the binary nature of the system. We obtain a circular orbital solution with an orbital period of 9.4 hr, a projected orbital radius of 2.8 lt-s, and a mass function of f = 0.15 M{sub sun} by analysis of spin period measurements. No evidence of orbital eccentricity is apparent; we set a 2{sigma} upper limit e {approx}< 1.7 x 10{sup -3}. The orbital parameters suggest amore » massive white dwarf companion with a minimum mass of 0.95 M{sub sun}, assuming a pulsar mass of 1.4 M{sub sun}. Most likely, this pulsar belongs to the rare class of intermediate-mass binary pulsars. Future timing observations will aim to determine the parameters of this system further, measure relativistic effects, and elucidate the nature of the companion star.« less
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  • The discovery of PSR 2303 + 46, the fifth radio pulsar known to be in a gravitationally bound orbit around another star, is reported. The pulsar period (1.066 s) and the orbital eccentricity (0.658) are the largest among the five binary systems, while the orbital period (12.34d) lies near the middle of the range. Evolutionary considerations suggest strongly that the companion is another neutron star. The general relativistic precession of periastron should be observable within 1 or 2 yr and, when measured, will specify the total mass of the two stars. 12 references.
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