Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/1534

Title

The 2003 radio outburst of a new X-ray transient: XTE J1720-318

Author(s)

Brocksopp, Catherine;  Corbel, Stephane;  Fender, Robert P.;  Rupen, M.;  Sault, R.;  Tingay, Steven J.;  Hannikainen, D.;  O'Brien, K.

Abstract

We present radio observations of the black hole X-ray transient XTE J1720−318, which was discovered in 2003 January as it entered an outburst. We analyse the radio data in the context of the X-ray outburst and the broad-band spectrum. An unresolved radio source was detected during the rising phase, reaching a peak of nearly 5 mJy approximately coincident with the peak of the X-ray light curve. A study of the spectral indices suggests that at least two ejection events took place, with the radio-emitting material expanding and becoming optically thin as it faded. The broad-band spectra suggested that the accretion disc dominated the emission, as expected for a source in a soft state. The radio emission decayed to below the sensitivity of the telescopes for 6 weeks but switched on again during the transition of the X-ray source to the low/hard state. At least one 'glitch' was superimposed on the otherwise exponential decay of the X-ray light curve, which was reminiscent of the multiple jet ejections of XTE J1859+226. We also present a Ks-band image of XTE J1720−318 and its surrounding field taken with the Very Large Telescope.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Monthly Notices of the Royal Astronomical Society, Vol. 356, no. 1 (2005), pp. 125-130

Publication year

2005

FOR Code(s)

0201 Astronomical and Space Sciences

Publisher

Blackwell

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1111/j.1365-2966.2004.08427.x

Copyright

Copyright © 2004 Royal Astronomical Society.

Peer reviewed