e-VLBI observations of Circinus X-1: monitoring of the quiescent and flaring radio emission on au scales
|dc.identifier.citation||Moin, A. and Reynolds, C. and Miller-Jones, J. and Tingay, S. and Phillips, C. and Tzioumis, A. and Nicolson, G. et al. 2011. e-VLBI observations of Circinus X-1: monitoring of the quiescent and flaring radio emission on au scales. Monthly Notices of the Royal Astronomical Society. 414 (4): pp. 3551-3556.|
A recent detection of the peculiar neutron star X-ray binary Circinus X-1 with electronic very long baseline interferometry (e-VLBI) prompted the suggestion that compact, non-variable radio emission persists through the entire 16.6-d orbit of the binary system. We present the results of a high angular resolution monitoring campaign conducted with the Australian Long Baseline Array in real-time e-VLBI mode. e-VLBI observations of Circinus X-1 were made on alternate days over a period of 20 d covering the full binary orbit. A compact radio source associated with Circinus X-1 was clearly detected at orbital phases following periastron passage, but no compact radio emission was detected at any other orbital phase, ruling out the presence of a persistent, compact emitting region at our sensitivity levels. The jet was not resolved at any epoch of our 1.4-GHz monitoring campaign, suggesting that the ultrarelativistic flow previously inferred to exist in this source is likely to be dark. We discuss these findings within the context of previous radio monitoring of Circinus X-1.
|dc.publisher||Oxford University Press|
|dc.subject||stars: individual: Circinus X-1|
|dc.title||e-VLBI observations of Circinus X-1: monitoring of the quiescent and flaring radio emission on au scales|
|dcterms.source.title||Monthly Notices of the Royal Astronomical Society|
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2011 The Authors, © 2011Royal Astronomical Society. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
|curtin.department||Curtin Institute of Radio Astronomy (Physics)|