Publications by Katherine Blundell


Cosmic ray acceleration in hydromagnetic flux tubes

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 487 (2019) 4571-4579

AR Bell, JH Matthews, KM Blundell, AT Araudo


Ultrahigh energy cosmic rays from shocks in the lobes of powerful radio galaxies

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 482 (2019) 4303-4321

JH Matthews, AR Bell, KM Blundell, AT Araudo


Cosmic ray acceleration by shocks: spectral steepening due to turbulent magnetic field amplification

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 488 (2019) 2466-2472

AR Bell, JH Matthews, KM Blundell


SS433's Jet Trace from ALMA Imaging and Global Jet Watch Spectroscopy: Evidence for Post-launch Particle Acceleration

ASTROPHYSICAL JOURNAL LETTERS 867 (2018) ARTN L25

KM Blundell, R Laing, S Lee, A Richards


On the maximum energy of non-thermal particles in the primary hotspot of Cygnus A

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 473 (2018) 3500-3506

AT Araudo, AR Bell, KM Blundell, JH Matthews


Fornax A, Centaurus A, and other radio galaxies as sources of ultrahigh energy cosmic rays

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 479 (2018) L76-L80

JH Matthews, AR Bell, KM Blundell, AT Araudo


Cosmic-ray acceleration by relativistic shocks: limits and estimates

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 473 (2018) 2364-2371

AR Bell, AT Araudo, JH Matthews, KM Blundell


Evidence that particle acceleration in hotspots of FR II galaxies is not constrained by synchrotron cooling

Nuclear and Particle Physics Proceedings 297-299 (2018) 242-248

A Araudo, AR BELL, K BLUNDELL

© 2018 We study the hotspots of powerful radiogalaxies, where electrons accelerated at the jet termination shock emit synchrotron radiation. The turnover of the synchrotron spectrum is typically observed between infrared and optical frequencies, indicating that the maximum energy of non-thermal electrons accelerated at the shock is ≲ TeV for a canonical magnetic field of ∼100 μG. We show that this maximum energy cannot be constrained by synchrotron losses as usually assumed, unless the jet density is unreasonably large and most of the jet upstream energy goes to non-thermal particles. We test this result by considering a sample of hotspots observed at radio, infrared and optical wavelengths.


LOFAR 150-MHz observations of SS 433 and W 50

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 475 (2018) 5360-5377

JW Broderick, RP Fender, JCA Miller-Jones, SA Trushkin, AJ Stewart, GE Anderson, TD Staley, KM Blundell, M Pietka, S Markoff, A Rowlinson, JD Swinbank, AJ van der Horst, ME Bell, RP Breton, D Carbone, S Corbel, J Eisloeffel, H Falcke, J-M Griessmeier, JWT Hessels, VI Kondratiev, CJ Law, GJ Molenaar, M Serylak, BW Stappers, J van Leeuwen, RAMJ Wijers, R Wijnands, MW Wise, P Zarka


Amplification of perpendicular and parallel magnetic fields by cosmic ray currents

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 469 (2017) 1849-1860

JH Matthews, AR Bell, KM Blundell, AT Araudo


Deep 230-470 MHz VLA Observations of the mini-halo in the Perseus Cluster

MNRAS 469 (2017) 2017-2017

M Gendron-Marsolais, J Hlavacek-Larrondo, RJV Weeren, T Clarke, AC Fabian, HT Intema, GB Taylor, KM Blundell, JS Sanders

We present a low-frequency view of the Perseus cluster with new observations from the Karl G. Jansky Very Large Array (JVLA) at 230-470 MHz. The data reveal a multitude of new structures associated with the mini-halo. The mini-halo seems to be influenced both by the AGN activity as well as by the sloshing motion of the cool core cluster's gas. In addition, it has a filamentary structure similar to that seen in radio relics found in merging clusters. We present a detailed description of the data reduction and imaging process of the dataset. The depth and resolution of the observations allow us to conduct for the first time a detailed comparison of the mini-halo structure with the X-ray structure as seen in the Chandra X-ray images. The resulting image shows very clearly that the mini-halo emission is mostly contained behind the cold fronts, similar to that predicted by simulations of gas sloshing in galaxy clusters. However, due to the proximity of the Perseus cluster, as well as the quality of the data at low radio frequencies and at X-ray wavelengths, we also find evidence of fine structure. This structure includes several radial radio filaments extending in different directions, a concave radio structure associated with the southern X-ray bay and sharp edges that correlate with X-ray edges. Mini-halos are therefore not simply diffuse, uniform radio sources, but are rather filled with a rich variety of complex structures. These results illustrate the high-quality images that can be obtained with the new JVLA at low radio-frequencies, as well as the necessity to obtain deeper, higher-fidelity radio images of mini-halos and halos in clusters to further understand their origin.


Fast launch speeds in radio flares, from a new determination of the intrinsic motions of SS 433's jet bolides

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 461 (2016) 312-320

RM Jeffrey, KM Blundell, SA Trushkin, AJ Mioduszewski


A very deep Chandra view of metals, sloshing and feedback in the Centaurus cluster of galaxies

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP): Policy P - Oxford Open Option A (2016)

KM Blundell


Evidence that the maximum electron energy in hotspots of FR II galaxies is not determined by synchrotron cooling

Monthly Notices of the Royal Astronomical Society (2016) stw1204-stw1204

AT Araudo, AR Bell, A Crilly, KM Blundell


A very deep Chandra view of metals, sloshing and feedback in the Centaurus cluster of galaxies

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 457 (2016) 82-109

JS Sanders, AC Fabian, GB Taylor, HR Russell, KM Blundell, REA Canning, J Hlavacek-Larrondo, SA Walker, CK Grimes


Black Holes: A Very Short Introduction

Oxford University Press, 2015

K Blundell

In this Very Short Introduction, Katherine Blundell addresses a variety of questions, including what a black hole actually is, how they are characterised and discovered, to what happens if you get too close to one.


Multiwavelength study of Cygnus A V. The hotspots in the lobe

ASTRONOMY & ASTROPHYSICS 574 (2015) ARTN A30

S Pyrzas, KC Steenbrugge, KM Blundell


PARTICLE ACCELERATION AND MAGNETIC FIELD AMPLIFICATION IN THE JETS OF 4C74.26

ASTROPHYSICAL JOURNAL 806 (2015) ARTN 243

AT Araudo, AR Bell, KM Blundell


Do high-redshift quasars have powerful jets?

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 442 (2014) L81-L84

AC Fabian, SA Walker, A Celotti, G Ghisellini, P Mocz, KM Blundell, RG McMahon


Near infrared extinction at the galactic centre

in Astrophysics and Space Science Proceedings, 37 (2013) 201-206

AJ Gosling, RM Bandyopadhyay, KM Blundell

© Springer Science+Business Media Dordrecht 2013. We present new results from UKIDSS on the Nuclear Bulge of our Galaxy that shows the previous determinations of the extinction parameter need revising.

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