Publications (18)
Multiwavelength study of Cygnus A II. X-ray inverse-Compton emission from a relic counterjet and implications for jet duty-cycles
K. C. Steenbrugge, K. M. Blundell, P. Duffy
The duty-cycle of powerful radio galaxies and quasars such as the prototype Cygnus A is poorly understood. X-ray observations of inverse-Compton scattered Cosmic Microwave Backgrou…
Progenitor, environment, and modelling of the interacting transient, AT 2016jbu (Gaia16cfr)
S. J. Brennan, M. Fraser, J. Johansson +67
We present the bolometric lightcurve, identification and analysis of the progenitor candidate, and preliminary modelling of AT2016jbu (Gaia16cfr). We find a progenitor consistent w…
A MODEL FOR THE RADIO EMISSION FROM SNR 1987A
P. Duffy, Lewis Ball, J. G. Kirk
The observations of radio emission from SNR~1987A can be accounted for on the basis of diffusive shock acceleration of electrons by the supernova blast wave. However, with this int…
Environmental limits on the non-resonant cosmic-ray current-driven instability
B. Reville, J. G. Kirk, P. Duffy +1
We investigate the so-called non-resonant cosmic-ray streaming instability, first discussed by Bell (2004). The extent to which thermal damping and ion-neutral collisions reduce th…
Particle acceleration efficiencies in astrophysical shear flows
F. M. Rieger, P. Duffy
The acceleration of energetic particles in astrophysical shear flows is analyzed. We show that in the presence of a non-relativistic gradual velocity shear, power law particle mome…
Relativistic Blastwaves and Synchrotron Emission
T. P. Downes, P. Duffy, S. Komissarov
Relativistic shocks accelerate particles by the first order Fermi mechanism. These particles then emit synchrotron emission in the post shock gas. We have developed a numerical cod…
Particle acceleration and relativistic shocks
J. G. Kirk, P. Duffy
Observations of both gamma-ray burst sources and certain classes of active galaxy indicate the presence of relativistic shock waves and require the production of high energy partic…
Shear Acceleration in Expanding Flows
F. M. Rieger, P. Duffy
Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the ef…
Radio Supernovae as Tev Gamma-Ray Sources
J. G. Kirk, P. Duffy, Lewis Ball
When applied to the blast wave formed by the explosion of a massive star as a supernova (SN), the theory of diffusive particle acceleration at shock fronts predicts a very high ene…
Steady-State Solutions in Nonlinear Diffusive Shock Acceleration
B. Reville, J. G. Kirk, P. Duffy
Stationary solutions to the equations of non-linear diffusive shock acceleration play a fundamental role in the theory of cosmic-ray acceleration. Their existence usually requires…
Anomalous Transport and Particle Acceleration at Shocks
P. Duffy, J. G. Kirk, Y. A. Gallant +1
The theory of first order Fermi acceleration at shocks assumes that particles diffuse due to scattering off slow-moving magnetic irregularities. However, cosmic rays are closely ti…
A current driven instability in parallel, relativistic shocks
B. Reville, J. G. Kirk, P. Duffy
Recently, Bell has reanalysed the problem of wave excitation by cosmic rays propagating in the pre-cursor region of a supernova remnant shock front. He pointed out a strong, non-re…
Detection of a relic X-ray jet in Cygnus A
K. C. Steenbrugge, K. M. Blundell, P. Duffy
We present a 200 ks Chandra ACIS-I image of Cygnus A, and discuss a long linear feature seen in its counterlobe. This feature has a non-thermal spectrum and lies on the line connec…
Stochastic particle acceleration at shocks in the presence of braided magnetic fields
J. G. Kirk, P. Duffy, Y. A. Gallant
The theory of diffusive acceleration of energetic particles at shock fronts assumes charged particles undergo spatial diffusion in a uniform magnetic field. If, however, the magnet…
Cosmic Ray Hydrodynamics at Shock Fronts
P. Duffy, L. O'C. Drury, H. J. Voelk
When a magnetised, thermal plasma containing a shock wave efficiently accelerates Cosmic Rays (CR) a reaction is exerted on the fluid structure. The simplest description of this pr…
A cosmic ray current driven instability in partially ionised media
B. Reville, J. G. Kirk, P. Duffy +1
We investigate the growth of hydromagnetic waves driven by streaming cosmic rays in the precursor environment of a supernova remnant shock. It is known that transverse waves propag…
The transport of cosmic rays in self-excited magnetic turbulence
B. Reville, S. O'Sullivan, P. Duffy +1
The process of diffusive shock acceleration relies on the efficacy with which hydromagnetic waves can scatter charged particles in the precursor of a shock. The growth of self-gene…
Photometric and spectroscopic evolution of the interacting transient AT 2016jbu (Gaia16cfr)
S. J. Brennan, M. Fraser, J. Johansson +68
We present the results from a high cadence, multi-wavelength observation campaign of AT 2016jbu (aka Gaia16cfr), an interacting transient. This dataset complements the current lite…