PSR J1740−3052: a pulsar with a massive companion |
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| Authors: | IH Stairs RN Manchester AG Lyne VM Kaspi † F Camilo JF Bell N D'Amico M Kramer F Crawford ‡ DJ Morris A Possenti NPF McKay SL Lumsden LE Tacconi-Garman RD Cannon NC Hambly PR Wood |
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| Institution: | 1University of Manchester, Jodrell Bank Observatory, Macclesfield, Cheshire SK11 9DL;2National Radio Astronomy Observatory, PO Box 2, Green Bank, WV 24944, USA;3Australia Telescope National Facility, CSIRO, PO Box 76, Epping, NSW 1710, Australia;4Physics Department, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8, Canada;5Columbia Astrophysics Laboratory, Columbia University, 550 W. 120th Street, New York, NY 10027, USA;6Osservatorio Astronomico di Bologna, via Ranzani 1, 40127 Bologna, Italy;7Instituto di Radioastronomia del CNR, via Gobetti 101, 40129 Bologna, Italy;8Massachusetts Institute of Technology, Center for Space Research, 70 Vassar Street, Cambridge, MA 02139, USA;9Department of Physics and Astronomy, E. C. Stoner Building, University of Leeds, Leeds, W. Yorkshire L52 9JT;10Max-Planck-Institut für Extraterrestrische Physik, Postfach 1312, 85741 Garching, Germany;11Anglo-Australian Observatory, PO Box 296, Epping, NSW 1710, Australia;12Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ;13Research School of Astronomy &Astrophysics, Institute of Advanced Studies, The Australian National University, Cotter Road, Weston Creek, ACT 2611, Australia |
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| Abstract: | We report on the discovery of a binary pulsar, PSR J1740?3052, during the Parkes multibeam survey. Timing observations of the 570-ms pulsar at Jodrell Bank and Parkes show that it is young, with a characteristic age of 350 kyr, and is in a 231-d, highly eccentric orbit with a companion whose mass exceeds 11 M⊙. An accurate position for the pulsar was obtained using the Australia Telescope Compact Array. Near-infrared 2.2-μm observations made with the telescopes at the Siding Spring observatory reveal a late-type star coincident with the pulsar position. However, we do not believe that this star is the companion of the pulsar, because a typical star of this spectral type and required mass would extend beyond the orbit of the pulsar. Furthermore, the measured advance of periastron of the pulsar suggests a more compact companion, for example, a main-sequence star with radius only a few times that of the Sun. Such a companion is also more consistent with the small dispersion measure variations seen near periastron. Although we cannot conclusively rule out a black hole companion, we believe that the companion is probably an early B star, making the system similar to the binary PSR J0045?7319. |
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| Keywords: | binaries: general stars: late-type stars: mass-loss pulsars: general pulsars: individual: PSR J1740?3052 X-rays: stars |
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