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Identification of the nebula G70.7 + 1.2 as a bow shock powered by a pulsar/Be-star binary

Kulkarni, S. R. and Vogel, S. N. and Wang, Z. and Wood, D. O. S. (1992) Identification of the nebula G70.7 + 1.2 as a bow shock powered by a pulsar/Be-star binary. Nature, 360 (6400). pp. 139-141. ISSN 0028-0836. doi:10.1038/360139a0.

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The enigmatic radio and optical nebula G70.7 + 1.2 has been suggested to be a young supernova remnant a nova shell, a cometary H II region and a protostellar outflow. Claims of strong nonthermal radio emission cast severe doubts on all but the supernova remnant model, but for this the expansion velocity would be low. We present here new data that firmly establish the nonthermal nature of the radio emission, and from Hα and [O I] Fabry–Perot observations we argue that the extended optical emission arises from a bow shock powered by a mass-losing luminous (Be) star moving supersonically through dense gas. The nonthermal emission is then explained as the shocked relativistic wind from a pulsar, which we propose is a companion to the Be star. The coincidence of the optical and radio emission requires the pulsar and stellar winds to be mixed together. The system has a large overall velocity, ~60 km s^(−1), which is inexplicable in all other models but which is typical of binary pulsars. Detection of pulsed emission and of the predicted proper motion would confirm our proposal.

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Kulkarni, S. R.0000-0001-5390-8563
Additional Information:© 1992 Nature Publishing Group. Received 10 June; accepted 14 September 1992. We thank J. Bally for interesting S.R.K. in this object, T. Herbig and A. Readhead for obtaining the OVRO 22-GHz measurements, G. Vasisht for help with the Fabry-Perot observations, J. A. Phillips for informing us of his results before publication, and R. Blandford, M. Cohen. D. Green, J. A. Phillips and D. Van Buren for discussion. OVRO is supported by a grant from the U.S. NSF. The 60-inch telescope is jointly operated by Caltech and the Carnegie Institution of Washington. The VLA is operated by Associated Universities, Inc., under contract to NSF. We acknowledge financial support from NSF and NASA. S.R.K. thanks the Packard Foundation and the Perkin Fund for support.
Group:UNSPECIFIED, Division of Geological and Planetary Sciences
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David and Lucile Packard FoundationUNSPECIFIED
Issue or Number:6400
Record Number:CaltechAUTHORS:20150609-113728156
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Official Citation:Identification of the nebula G70.7 + 1.2 as a bow shock powered by a pulsar/Be-star binary 139 S. R. Kulkarni, S. N. Vogel, Z. Wang & D. O. S. Wood doi:10.1038/360139a0
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:58116
Deposited By: Ruth Sustaita
Deposited On:10 Jun 2015 15:25
Last Modified:10 Nov 2021 21:59

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