A5017514704- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Galaxies: Formation, Evolution, Phenomena
- SAS software applications and methods
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Particle accelerators and beam dynamics
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Spacecraft and Cryogenic Technologies
- Mechanics and Biomechanics Studies
- Magnetic confinement fusion research
- Calibration and Measurement Techniques
- Nuclear Physics and Applications
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Sports Dynamics and Biomechanics
- Plant Water Relations and Carbon Dynamics
- Energetic Materials and Combustion
- HVDC Systems and Fault Protection
- Ocular and Laser Science Research
- Cyclone Separators and Fluid Dynamics
University of Manchester
2017-2020
University College Cork
2013-2016
University of Central Lancashire
2016
University of Southampton
2015
Geoscience BC
1966
We present results of the coordinated observing campaign that made first subarcsecond localization a Fast Radio Burst, FRB 121102. During this campaign, we simultaneous detection an burst by multiple telescopes: VLA at 3 GHz and Arecibo Observatory 1.4 GHz. Of nine bursts detected Very Large Array GHz, four had coverage other observatories. use multi-observatory constraints modeling seen only to confirm earlier showing spectra are not well modeled power law. find characterized ~500 MHz...
We present a radio-quiet quasar at z=0.237 discovered "turning on" by the intermediate Palomar Transient Factory (iPTF). The transient, iPTF 16bco, was detected in nucleus of galaxy with an archival SDSS spectrum weak narrow-line emission characteristic low-ionization line region (LINER). Our follow-up spectra show dramatic appearance broad Balmer lines and power-law continuum luminous (L_bol~10^45 erg/s) type 1 12 years later. photometric monitoring PTF from 2009-2012, serendipitous X-ray...
We present the Multifrequency Snapshot Sky Survey (MSSS), first northern-sky LOFAR imaging survey. In this introductory paper, we describe in detail motivation and design of Compared to previous radio surveys, MSSS is exceptional due its intrinsic multifrequency nature providing information about spectral properties detected sources over more than two octaves (from 30 160 MHz). The broadband frequency coverage, together with fast survey speed generated by LOFAR's multibeaming capabilities,...
We present ground-based and \textit{Swift} observations of iPTF16fnl, a likely tidal disruption event (TDE) discovered by the intermediate Palomar Transient Factory (iPTF) survey at 66.6 Mpc. The lightcurve object peaked absolute $M_g=-17.2$ mag. maximum bolometric luminosity (from optical UV) was $L_p~\simeq~(1.0\,\pm\,0.15) \times 10^{43}$ erg/s, an order magnitude fainter than any other TDE so far. in first 60 days is consistent with exponential decay, $L \propto e^{-(t-t_0)/\tau}$, where...
Calcium rich gap transients represent an intriguing new class of faint and fast evolving supernovae that exhibit strong [Ca II] emission in their nebular phase spectra. In this paper, we present the discovery follow-up observations iPTF 16hgs -- intermediate luminosity transient exhibited a double peaked light curve. Exhibiting typical Type Ib spectrum photospheric early transition to dominated phase, show shows properties consistent with Ca-rich transients, two interesting exceptions....
Low-frequency radio continuum observations of edge-on galaxies are ideal to study cosmic-ray electrons (CREs) in halos via synchrotron emission and measure magnetic field strengths. We obtained new the spiral galaxy NGC 891 at 129-163 MHz with LOw Frequency ARray (LOFAR) 13-18 GHz Arcminute Microkelvin Imager (AMI) combine them recent high-resolution Very Large Array (VLA) 1-2 GHz, enabling us over two orders magnitude frequency. The spectrum integrated nonthermal flux density can be fitted...
We report on late time radio and X-ray observations of the tidal disruption event candidate ASASSN-14li, covering first 1000 days decay phase. For $\sim200$ emission fade in concert. This phase is better fit by an exponential at wavelengths, while well described either or canonical $t^{-5/3}$ assumed for events. The correlation between during this period can be as $L_{R}\propto L_{X}^{1.9\pm0.2}$. After 400 $15.5\,\textrm{GHz}$ has reached a plateau level $244\pm8\,\mu\textrm{Jy}$ which it...
We present multi-wavelength follow-up campaigns by the AstroSat-CZTI and GROWTH collaborations to search for an electromagnetic counterpart gravitational wave event GW170104. At time of GW170104 trigger, AstroSat CZTI field-of-view covered 50.3\% sky localization. do not detect any hard X-ray (>100 keV) signal at this time, place upper limit $\approx 4.5 \times 10^{-7}~{\rm erg~cm}^{-2}{\rm~s}^{-1}$ a 1\,s timescale. Separately, ATLAS survey reported rapidly fading optical source dubbed...
Abstract An earlier study of the complex jet 3C 380 by Papageorgiou et al. revealed total intensity and polarization structure associated with a bright knot K1 about 0.7 arcsec from core that was reminiscent expected for conical shock wave. In this new study, 1.42, 1.66 4.99 GHz intensity, Faraday rotation images are presented analysed. These were derived observations Very Long Baseline Array plus one antenna Large Array, obtained in 2006 March. confirm overall magnetic field indicated...
We report on the discovery in LOFAR Multifrequency Snapshot Sky Survey (MSSS) of a giant radio galaxy (GRG) with projected size 2.56 ± 0.07 Mpc sky. It is associated triplet UGC 9555, within which one identified as broad-line Sloan Digital (SDSS) at redshift 0.05453 1 × 10-5, and velocity dispersion 215.86 6.34 km s-1. From archival observations we see that this hosts compact flat-spectrum source, conclude it active galactic nucleus (AGN) responsiblefor generating lobes. The luminosity...
We report the discovery of a radio halo in massive merging cluster MACSJ2243.3-0935,as well as new relic candidate, using Giant Meterwave Radio Telescope and KAT-7 telescope.The is coincident with X-ray emission has largest linear scale approximately 0.9 Mpc.We measure flux density 10.0 ± 2.0 mJy at 610 MHz for halo.We discuss equipartition estimates magnetic field constrain value to be order 1 µG.The candidate detected virial radius where filament meets cluster.The 5.2 0.8 MHz.We possible...
We present LOFAR observations at 150 MHz of the borderline FRI/FRII giant radio galaxy NGC 6251. This paper presents most sensitive and highest-resolution images 6251 these frequencies to date, revealing for first time a low-surface-brightness extension northern lobe, possible backflow associated with southern lobe. The integrated spectra components are consistent previous measurements higher frequencies, similar results from other studies nearby galaxies. find outer structures be either...
The candidate black hole X-ray binary Swift J1753.5-0127 faded to quiescence in 2016 November, after a prolonged outburst that was discovered 2005. Nearly three months later the system displayed renewed activity lasted through 2017 July. Here, we present radio and monitoring over ~3 of study coupling between jet inner regions disk/jet system. Our observations cover low luminosities have not historically been well-sampled (Lx~2e33 - 1e36 erg/s; 1-10 keV), including time periods when both...
We present LOFAR data from 110–180 MHz of the merging galaxy cluster Abell 1682, alongside archival optical, radio, and X-ray data. Our images 6 arcsec in resolution at low frequencies reveal new structures associated with numerous radio galaxies cluster. At a 20 we see diffuse emission throughout over hundreds kiloparsecs, indicating particle acceleration mechanisms are play as result merger event powerful active galactic nuclei. show that significant part is an old very steep spectrum...
High-voltage dc transmission has been proposed for linking the power networks of Pacific Northwest and Southwest. An advantage direct current, not possessed by alternating is that one-half rated a line can be transmitted, with one conductor out service, allowing current in remaining to return through earth. To realize this advantage, however, it necessary insure against certain possible harmful effects from ground flow.
The high-mass X-ray binary LS I +61°303 exhibits variability in its radio and emissions, ranging from minute to hour time-scales. At such short time-scales, not much is known about the possible correlations between these two emissions this source, which might offer hints their origin. Here, we study relationship using simultaneous monitoring. We present new observations Arcminute Microkelvin Imager Large Array telescope at frequency bands, 13-15.5 15.5-18 GHz. also describe performed...
The Arcminute Microkelvin Imager (AMI) carried out a blind survey for galaxy clusters via their Sunyaev-Zel'dovich effect decrements between 2008 and 2011. first detection, known as AMI-CL J0300+2613, has been reobserved with AMI equipped new digital correlator high dynamic range. combination of the data more recent high-resolution sub-mm infra-red maps now shows feature in fact to be ring positive dust-correlated Galactic emission, which is likely anomalous microwave emission (AME). If so,...
The Square Kilometre Array (SKA) will be the world's largest radio telescope. pre-construction design effort for SKA started in 2012 and involves approximately 100 organizations 20 countries. scale of project makes it a huge scientific endeavour, not only terms science that ultimately undertake, but also engineering development is required to build such unique instrument. This now drawing close early operations are anticipated begin ~2025.
We present the detection of a bright 3mm continuum source in Brightest Cluster Galaxy (BCG) Abell 851 (z=0.411) with NOrthern Extended Millimeter Array (NOEMA). When this is compared to other multi-frequency observations across 21cm-100um, including new Arcminute Microkelvin Imager 15GHz observations, we find evidence for relatively flat, variable core associated BCG. The radio power and amplitude variability observed galaxy consistent cores lower redshift BCGs X-ray-selected clusters, flat...