Colloq Abstract - Miller-Jones

June 21, 2019

11:00am Mountain

James Miller-Jones (Curtin)

A rapidly changing jet orientation from a stellar-mass black hole

 

Abstract

 

Powerful relativistic jets are one of the main ways in which accreting black holes provide kinetic feedback to their surroundings. Jets launched from or redirected by the accretion flow that powers them are expected to be affected by the dynamics of the flow.  Recent X-ray timing observations of accreting stellar-mass black holes have shown evidence for Lense-Thirring precession when the black hole spin axis is misaligned with the orbital plane of its companion star.  While the interplay between the dynamics of the accretion flow and the launching of the jets is still unclear, theoretical simulations have suggested that the jets and a precessing accretion flow can be coupled by pressure or magnetic torques.

In this talk, I will present high-resolution, time-resolved VLBA imaging of the 2015 outburst of the black hole X-ray binary system V404 Cygni, showing that at the peak of the outburst the jet orientation was changing on timescales of minutes to hours.  I will show that this can be modelled as the Lense-Thirring precession of a vertically extended slim disk that arises from the super-Eddington accretion rate.  This scenario would suggest that the dynamics of the precessing inner accretion disk could play a role in either directly launching or redirecting the jets within the inner few hundred gravitational radii.  I will discuss the implications of these results, and conclude by briefly considering the likely prevalence of such phenomena, and how this could be further explored via new imaging algorithms.


 

 

 

Connect with NRAO

The National Radio Astronomy Observatory and Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.

The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."

AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.