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Periodic bursts of coherent radio emission from an ultracool dwarf

Hallinan, G. and Bourke, S. and Lane, C. and Antonova, A. and Zavala, R. T. and Brisken, W. F. and Boyle, R. P. and Vrba, F. J. and Doyle, J. G. and Golden, A. (2007) Periodic bursts of coherent radio emission from an ultracool dwarf. Astrophysical Journal Letters, 663 (1). L25-L28. ISSN 2041-8205. http://resolver.caltech.edu/CaltechAUTHORS:20140211-095154940

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Abstract

We report the detection of periodic (p = 1.96 hr) bursts of extremely bright, 100% circularly polarized, coherent radio emission from the M9 dwarf TVLM 513-46546. Simultaneous photometric monitoring observations have established this periodicity to be the rotation period of the dwarf. These bursts, which were not present in previous observations of this target, confirm that ultracool dwarfs can generate persistent levels of broadband, coherent radio emission, associated with the presence of kG magnetic fields in a large-scale, stable configuration. Compact sources located at the magnetic polar regions produce highly beamed emission generated by the electron cyclotron maser instability, the same mechanism known to generate planetary coherent radio emission in our solar system. The narrow beams of radiation pass our line of sight as the dwarf rotates, producing the associated periodic bursts. The resulting radio light curves are analogous to the periodic light curves associated with pulsar radio emission highlighting TVLM 513-46546 as the prototype of a new class of transient radio source.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://iopscience.iop.org/1538-4357/663/1/L25/PublisherArticle
http://arxiv.org/abs/0705.2054arXivDiscussion Paper
http://dx.doi.org/10.1086/519790DOIArticle
Additional Information:© 2007 American Astronomical Society. Received 2007 February 20; accepted 2007 May 14; published 2007 June 15. We gratefully acknowledge the support of the HEA funded Cosmogrid project, the Irish Research Council for Science, Engineering, and Technology (IRCSET), and Enterprise Ireland. A. G. is supported by Science Foundation Ireland (grant 07/RFP/PHYF553). Armagh Observatory is grant-aided by the N. Ireland Department of Culture, Arts, and Leisure. We would like to thank Ray Butler, James Mc Donald, and Evan Keane for assistance with certain aspects of this manuscript and the referee Manuel Güdel, whose extensive comments significantly improved this manuscript.
Funders:
Funding AgencyGrant Number
HEA Cosmogrid ProjectUNSPECIFIED
Irish Research Council for Science, Engineering, and Technology (IRCSET)UNSPECIFIED
Enterprise Ireland UNSPECIFIED
Science Foundation Ireland07/RFP/PHYF553
Northern Ireland Department of Culture, Arts and Leisure (DCAL)UNSPECIFIED
Subject Keywords:pulsars: general; radio continuum: stars; radiation mechanisms: non-thermal; stars: activity; stars: low-mass, brown dwarfs; stars: magnetic fields
Record Number:CaltechAUTHORS:20140211-095154940
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20140211-095154940
Official Citation: Periodic Bursts of Coherent Radio Emission from an Ultracool Dwarf G. Hallinan et al. 2007 ApJ 663 L25
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:43770
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:11 Feb 2014 18:14
Last Modified:29 Aug 2014 14:47

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