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Discovery of Hard X-ray Pulsations from the Transient Source GRO J1744 - 28

Finger, M. H. and Koh, D.T. and Nelson, R. W. and Prince, Thomas A. and Vaughan, Brian A. and Wilson, Robert B. (1996) Discovery of Hard X-ray Pulsations from the Transient Source GRO J1744 - 28. Nature, 381 (23). pp. 291-293. ISSN 0028-0836. doi:10.1038/381291a0.

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An unusual astronomical source of hard X-ray bursts, GRO J1744 - 28, was discovered recently. The properties of this source differ markedly from those of other known high-energy burst sources-X-ray bursters, soft gamma-ray repeaters and gamma-ray bursters- suggesting that it may represent a new type of source. The bursts probably arise from unstable accretion of matter onto a compact object2, such as a neutron star, but the nature of the object and the origin of the burst instability have not been revealed by observations of the bursts themselves. Here we report the detection of coherent X-ray pulsations, with a period of 467 milliseconds, from GRO J1744 - 28; these are the first persistent pulsations seen in a bursting X-ray source. These pulses and their timing indicate that the object is a magnetized neutron star, accreting gas from a low-mass companion star. The pulsation rate has been increasing during the period of our observations, indicating that an accretion disk has been formed and that the transfer of matter from the disk is spinning up the neutron star. The source of the instability that leads to the bursts remains unknown.

Item Type:Article
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Prince, Thomas A.0000-0002-8850-3627
Additional Information:© 1996 Nature Publishing Group. Received 8 February; accepted 10 April 1986. We thank J. van Paradijs for useful discussions, D. Tahmoush for conducting searches in archival BATSE data for prior outburst of GRO J17 44-28, and C. Wilson for analysing occultation data for pulse fraction determination.
Group:Space Radiation Laboratory
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Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory1997-26
Issue or Number:23
Record Number:CaltechAUTHORS:20141106-095924533
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Official Citation:Nature 381, 291 - 293 (23 May 1996); doi:10.1038/381291a0
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:51361
Deposited By: Deborah Miles
Deposited On:08 Nov 2014 00:18
Last Modified:10 Nov 2021 19:09

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