Search Publications
A tidal disruption event coincident with a high-energy neutrino
Kilpatrick, Charles D.; Foley, Ryan J.; Cenko, S. Bradley +55 more
Cosmic neutrinos provide a unique window into the otherwise hidden mechanism of particle acceleration in astrophysical objects. The IceCube Collaboration recently reported the likely association of one high-energy neutrino with a flare from the relativistic jet of an active galaxy pointed towards the Earth. However a combined analysis of many simi…
Ionized outflows from active galactic nuclei as the essential elements of feedback
Veilleux, Sylvain; Reynolds, Christopher S.; Guainazzi, Matteo +5 more
Outflows from active galactic nuclei (AGNs) are one of the fundamental mechanisms by which the central supermassive black hole interacts with its host galaxy. Detected in ≥50% of nearby AGNs, these outflows have been found to carry kinetic energy that is a large fraction of the AGN power, and thereby give `negative' feedback to their host galaxies…
Indications of stellar coronal mass ejections through coronal dimmings
Veronig, Astrid M.; Dissauer, Karin; Hudson, Hugh S. +3 more
Coronal mass ejections (CMEs) are huge expulsions of magnetized matter from the Sun and stars, traversing space with speeds of millions of kilometres per hour. Solar CMEs can cause severe space weather disturbances and consumer power outages on Earth, whereas stellar CMEs may even pose a hazard to the habitability of exoplanets. Although CMEs ejec…
The population of M dwarfs observed at low radio frequencies
Callingham, J. R.; Shimwell, T. W.; Vedantham, H. K. +12 more
Coherent low-frequency (≲200 MHz) radio emission from stars encodes the conditions of the outer corona, mass-ejection events and space weather1-5. Previous low-frequency searches for radio-emitting stellar systems have lacked the sensitivity to detect the general population, instead largely focusing on targeted studies of anomalously ac…
Fast magnetic field amplification in distant galaxy clusters
Gastaldello, Fabio; Simionescu, Aurora; Brunetti, Gianfranco +16 more
In the present-day Universe, magnetic fields pervade galaxy clusters1 and have strengths of a few microgauss, as measured from Faraday rotation2. Evidence for cluster magnetic fields is also provided by the observation of megaparsec-scale radio emission, namely radio halos and relics3. These are commonly found in m…
Evidence for a compact object in the aftermath of the extragalactic transient AT2018cow
Steiner, James F.; Homan, Jeroen; Chakrabarty, Deepto +16 more
The brightest fast blue optical transients (FBOTs) are mysterious extragalactic explosions that may represent a new astrophysical phenomenon1. Their fast time to maximum brightness of less than a week, decline over several months, and atypical optical spectra and evolution are difficult to explain within the context of the core collapse…
Strong toroidal magnetic fields required by quiescent X-ray emission of magnetars
Igoshev, Andrei P.; Hollerbach, Rainer; Wood, Toby +1 more
Magnetars are neutron stars (NSs) with extreme magnetic fields1 of strength 5 × 1013-1015 G. These fields are generated by dynamo action during the proto-NS phase, and are expected to have both poloidal and toroidal components2-6, although the energy of the toroidal component could be ten times larger
A universal correlation between warm and hot gas in the stripped tails of cluster galaxies
Yoshida, Michitoshi; Fossati, Matteo; Nulsen, Paul E. J. +7 more
The impact of ram pressure stripping on galaxy evolution is well known (for example, ref. 1). Recent multi-wavelength data have revealed many examples of galaxies undergoing stripping, often accompanied with multi-phase tails2-13. As energy transfer in the multi-phase medium is an outstanding question in astrophysics, galaxie…
A possible planet candidate in an external galaxy detected through X-ray transit
Soria, Roberto; Urquhart, Ryan; Kashyap, Vinay L. +4 more
Many lines of reasoning suggest that external galaxies should host planetary systems, but detecting them by methods typically used in our own Galaxy is not possible. An alternative approach is to study the temporal behaviour of X-rays emitted by bright extragalactic X-ray sources, where an orbiting planet would temporarily block the X-rays and cau…