Professor Rob Fender: Publications

An artist's impression of a relativistic jet propagating away from a black hole at close to the speed of light. Such jets are formed by the inner regions of the accretion flow: matter flowing inwards towards the black hole, via processes which are not yet fully understood. The accretion flow emits primarily in X-rays, the relativistic jet in the radio band: by combing observations in each band we can try and understand how such jets form and how much energy they carry away from the black hole.

A precise measurement of the magnetic field in the corona of the black hole binary V404 Cygni

Science American Association for the Advancement of Science 358:6368 (2017)

Authors:

Y Dallilar, SS Eikenberry, A Garner, RD Stelter, A Gottlieb, P Gandhi, P Casella, VS Dhillon, TR Marsh, SP Littlefair, L Hardy, Robert Fender, Kunal Mooley, DJ Walton, F Fuerst, M Bachetti, AJ Castro-Tirado, M Charcos, ML Edwards, NM Lasso-Cabrera, A Marin-Franch, K Ackley, JG Bennett, AJ Cenarro, B Chinn, HV Donoso, R Frommeyer, K Hanna, J Julian, P Miller, S Mullin, CH Murphey, C Packham, F Varosi, C Vega, C Warner, AN Ramaprakash, M Burse, S Punnadi, P Chordia, A Gerarts, H De Paz Martín, MM Calero, R Scarpa, SF Acosta, B Siegel, FF Pérez

Abstract:

Observations of binary stars containing an accreting black hole or neutron star often show x-ray emission extending to high energies (>10 kilo--electron volts), which is ascribed to an accretion disk corona of energetic particles akin to those seen in the solar corona. Despite their ubiquity, the physical conditions in accretion disk coronae remain poorly constrained. Using simultaneous infrared, optical, x-ray, and radio observations of the Galactic black hole system V404 Cygni, showing a rapid synchrotron cooling event in its 2015 outburst, we present a precise 461 ± 12 gauss magnetic field measurement in the corona. This measurement is substantially lower than previous estimates for such systems, providing constraints on physical models of accretion physics in black hole and neutron star binary systems.

Evolving morphology of the large-scale relativistic jets from XTE J1550−564

Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 472:1 (2017) 141-165

Authors:

Giulia Migliori, S Corbel, JA Tomsick, P Kaaret, RP Fender, AK Tzioumis, M Coriat, JA Orosz

A Multi-telescope Campaign on FRB 121102: Implications for the FRB Population

The Astrophysical Journal American Astronomical Society 850:1 (2017) 76

Authors:

CJ Law, MW Abruzzo, CG Bassa, GC Bower, S Burke-Spolaor, BJ Butler, T Cantwell, SH Carey, S Chatterjee, JM Cordes, P Demorest, J Dowell, R Fender, K Gourdji, K Grainge, JWT Hessels, J Hickish, VM Kaspi, TJW Lazio, MA McLaughlin, D Michilli, K Mooley, YC Perrott, SM Ransom, N Razavi-Ghods, M Rupen, A Scaife, P Scott, P Scholz, A Seymour, LG Spitler, K Stovall, SP Tendulkar, D Titterington, RS Wharton, PKG Williams

ThunderKAT: The MeerKAT Large Survey Project for Image-Plane Radio Transients

(2017)

Authors:

R Fender, PA Woudt, R Armstrong, P Groot, V McBride, J Miller-Jones, K Mooley, B Stappers, R Wijers, M Bietenholz, S Blyth, M Bottcher, D Buckley, P Charles, L Chomiuk, D Coppejans, S Corbel, M Coriat, F Daigne, WJG de Blok, H Falcke, J Girard, I Heywood, A Horesh, J Horrell, P Jonker, T Joseph, A Kamble, C Knigge, E Koerding, M Kotze, C Kouveliotou, C Lynch, T Maccarone, P Meintjes, S Migliari, T Murphy, T Nagayama, G Nelemans, G Nicholson, T O'Brien, A Oodendaal, N Oozeer, J Osborne, M Perez-Torres, S Ratcliffe, V Ribeiro, E Rol, A Rushton, A Scaife, M Schurch, G Sivakoff, T Staley, D Steeghs, I Stewart, J Swinbank, K van der Heyden, A van der Horst, B van Soelen, S Vergani, B Warner, K Wiersema

Energetic eruptions leading to a peculiar hydrogen-rich explosion of a massive star

Nature Nature Publishing Group 551:7679 (2017) 210-213

Authors:

I Arcavi, DA Howell, D Kasen, L Bildsten, G Hosseinzadeh, C McCully, ZC Wong, A Gal-Yam, J Sollerman, F Taddia, G Leloudas, C Fremling, PE Nugent, A Horesh, K Mooley, C Rumsey, SB Cenko, ML Graham, DA Perley, E Nakar, NJ Shaviv, O Bromberg, KJ Shen, EO Ofek, Y Cao, X Wang, F Huang, L Rui, T Zhang, W Li, Z Li, J Zhang, S Valenti, D Guevel, B Shappee, CS Kochanek, TW-S Holoien, AV Filippenko, Robert Fender, A Nyholm, O Yaron, MM Kasliwal, M Sullivan, N Blagorodnova, RS Walters, R Lunnan, D Khazov, I Andreoni, RR Laher

Abstract:

Every supernova so far observed has been considered to be the terminal explosion of a star. Moreover, all supernovae with absorption lines in their spectra show those lines decreasing in velocity over time, as the ejecta expand and thin, revealing slower-moving material that was previously hidden. In addition, every supernova that exhibits the absorption lines of hydrogen has one main light-curve peak, or a plateau in luminosity, lasting approximately 100 days before declining. Here we report observations of iPTF14hls, an event that has spectra identical to a hydrogen-rich core-collapse supernova, but characteristics that differ extensively from those of known supernovae. The light curve has at least five peaks and remains bright for more than 600 days; the absorption lines show little to no decrease in velocity; and the radius of the line-forming region is more than an order of magnitude bigger than the radius of the photosphere derived from the continuum emission. These characteristics are consistent with a shell of several tens of solar masses ejected by the progenitor star at supernova-level energies a few hundred days before a terminal explosion. Another possible eruption was recorded at the same position in 1954. Multiple energetic pre-supernova eruptions are expected to occur in stars of 95 to 130 solar masses, which experience the pulsational pair instability. That model, however, does not account for the continued presence of hydrogen, or the energetics observed here. Another mechanism for the violent ejection of mass in massive stars may be required.

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