Search Publications
TOI-2119: a transiting brown dwarf orbiting an active M-dwarf from NASA's TESS mission
Latham, David W.; Stassun, Keivan G.; Collins, Karen A. +27 more
We report the discovery of TOI-2119b, a transiting brown dwarf (BD) that orbits and is completely eclipsed by an active M-dwarf star. Using light-curve data from the Transiting Exoplanet Survey Satellite mission and follow-up high-resolution Doppler spectroscopic observations, we find the BD has a radius of Rb = 1.08 ± 0.03RJ…
Charting galactic accelerations - II. How to 'learn' accelerations in the solar neighbourhood
Evans, N. W.; Naik, A. P.; An, J. +1 more
Gravitational acceleration fields can be deduced from the collisionless Boltzmann equation, once the distribution function is known. This can be constructed via the method of normalizing flows from data sets of the positions and velocities of stars. Here, we consider application of this technique to the solar neighbourhood. We construct mock data …
Four bright eclipsing binaries with γ Doradus pulsating components: CM Lac, MZ Lac, RX Dra, and V2077 Cyg
Van Reeth, Timothy; Southworth, John
The study of pulsating stars in eclipsing binaries holds the promise of combining two different ways of measuring the physical properties of a star to obtain improved constraints on stellar theory. Gravity (g) mode pulsations such as those found in γ Doradus stars can be used to probe rotational profiles, mixing, and magnetic fields. Until recentl…
Probing vainsthein-screening gravity with galaxy clusters using internal kinematics and strong and weak lensing
Umetsu, Keiichi; Pizzuti, Lorenzo; Saltas, Ippocratis D. +1 more
We use high-precision combined strong/weak lensing and kinematics measurements of the total mass profiles of the observed galaxy clusters MACS J1206.2-0847 and Abell S1063, to constrain the relativistic sector of the general DHOST dark energy theories, which exhibit a partial breaking of the so called Vainsthein screening mechanism, on the linear …
Constraints on the Galactic Centre environment from Gaia hypervelocity stars II: The evolved population
Rossi, E. M.; Marchetti, T.; Evans, F. A.
A dynamical encounter between a stellar binary and Sgr A* in the Galactic Centre (GC) can tidally separate the binary and eject one member with a velocity beyond the escape speed of the Milky Way. These hypervelocity stars (HVSs) can offer insight into the stellar populations in the GC environment. In a previous work, our simulations showed that t…
Multiwavelength properties of 850-µm selected sources from the North Ecliptic Pole SCUBA-2 survey
Goto, Tomotsugu; Kim, Seong Jin; Conselice, Christopher J. +25 more
We present the multiwavelength counterparts of 850-$\mu$m selected submillimetre sources over a 2-deg2 field centred on the North Ecliptic Pole. In order to overcome the large beam size (15 arcsec) of the 850-$\mu$m images, deep optical to near-infrared (NIR) photometric data and arcsecond-resolution 20-cm images are used to identify co…
Synthetic solar cycle for active regions violating the Hale's polarity law
Abramenko, V.; Sokoloff, D.; Zhukova, A. +1 more
Long observational series for bipolar active regions (ARs) provide significant information about the mutual transformation of the poloidal and toroidal components of the global solar magnetic field. The direction of the toroidal field determines the polarity of leading sunspots in ARs in accordance with the Hale's polarity law. The vast majority o…
The detection of radio emission from known X-ray flaring star EXO 040830-7134.7
Woudt, P. A.; Williams, D. R. A.; Fender, R. P. +4 more
We report the detection of radio emission from the known X-ray flaring star EXO 040830-7134.7 during Karoo Array Telescope (MeerKAT) observations of the nearby cataclysmic variable VW Hydri. We have three epochs of MeerKAT observations, where the star is not detected in the first epoch, is detected in the second epoch, and is marginally detected i…
Relic jet activity in 'Hanny's Voorwerp' revealed by the LOFAR two metre sky survey
Hardcastle, M. J.; Smith, D. J. B.; Drake, A. B. +1 more
We report new observations of 'Hanny's Voorwerp' (hereafter HV) taken from the second data release of the LOFAR Two-metre Sky Survey (LoTSS). HV is a highly-ionized region in the environs of the galaxy IC2497, first discovered by the Galaxy Zoo project. The new 150 MHz observations are considered in the context of existing multi frequency radio da…
SoUthern Cluster sCale Extended Source Survey (SUCCESS): a GMRT and Meerkat study of nine massive galaxy clusters
Kale, R.; Venturi, T.; Joshi, D. C. +7 more
We aim to carry out a radio study of the SoUthern Cluster sCale Extended Source Survey (SUCCESS) sample consisting of 20 massive (M500 > 5 × 1014 M⊙), nearby (redshift <0.3) and southern (-50° < δ < -30°) galaxy clusters detected by the Planck satellite and the South Pole Telescope. Here, we report targ…