Search Publications
Spacecraft and interplanetary contributions to the magnetic environment on-board LISA Pathfinder
Mendes, L.; Russano, G.; Nofrarias, M. +79 more
LISA Pathfinder (LPF) has been a space-based mission designed to test new technologies that will be required for a gravitational wave observatory in space. Magnetically driven forces play a key role in the instrument sensitivity in the low-frequency regime (mHz and below), the measurement band of interest for a space-based observatory. The magneti…
Extreme variability in an active galactic nucleus: Gaia16aax
Hewett, P. C.; Kostrzewa-Rutkowska, Z.; Wevers, T. +12 more
We present the results of a multiwavelength follow-up campaign for the luminous nuclear transient Gaia16aax, which was first identified in 2016 January. The transient is spatially consistent with the nucleus of an active galaxy at z = 0.25, hosting a black hole of mass ∼ 6× 10^8 M_⊙. The nucleus brightened by more than 1 mag in the Gaia G band ove…
The Magellanic Edges Survey I: Description and first results
Da Costa, G. S.; Belokurov, V.; Koposov, S. E. +6 more
We present an overview of, and first science results from, the Magellanic Edges Survey (MagES), an ongoing spectroscopic survey mapping the kinematics of red clump and red giant branch stars in the highly substructured periphery of the Magellanic Clouds. In conjunction with Gaia astrometry, MagES yields a sample of ~7000 stars with individual 3D v…
Spectroscopic and photometric periods of six ultracompact accreting binaries
Dhillon, V. S.; Parsons, Steven G.; Littlefair, S. P. +19 more
Ultracompact accreting binary systems each consist of a stellar remnant accreting helium-enriched material from a compact donor star. Such binaries include two related sub-classes, AM CVn-type binaries and helium cataclysmic variables, in both of which the central star is a white dwarf. We present a spectroscopic and photometric study of six accre…
Vetting the optical transient candidates detected by the GWAC network using convolutional neural networks
Bertin, E.; Xu, Y.; Leroy, N. +11 more
The observation of the transient sky through a multitude of astrophysical messengers has led to several scientific breakthroughs in the last two decades, thanks to the fast evolution of the observational techniques and strategies employed by the astronomers. Now, it requires to be able to coordinate multiwavelength and multimessenger follow-up cam…
The ASAS-SN catalogue of variable stars - VIII. 'Dipper' stars in the Lupus star-forming region
Kochanek, C. S.; Stanek, K. Z.; Shappee, B. J. +9 more
Some young stellar objects such as T Tauri-like 'dipper' stars vary due to transient partial occultation by circumstellar dust, and observations of this phenomenon inform us of conditions in the planet-forming zones close to these stars. Although many dipper stars have been identified with space missions such as Kepler/K2, ground-based telescopes …
TIC 278825952: a triply eclipsing hierarchical triple system with the most intrinsically circular outer orbit
Mitnyan, T.; Pál, A.; Maxted, P. F. L. +2 more
We report the discovery of a compact triply eclipsing triple star system in the southern continuous viewing zone of the TESS space telescope. TIC 278825952 is a previously known, but unstudied circular eclipsing binary with a period of 4.781 d with a tertiary component in a wider, circular orbit of 235.55-d period that was found from three sets of…
Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421-0643
Siemiginowska, A.; Birkinshaw, M.; Worrall, D. M. +3 more
Despite the fact that kpc-scale inverse-Compton (iC) scattering of cosmic microwave background (CMB) photons into the X-ray band is mandated, proof of detection in resolved quasar jets is often insecure. High redshift provides favourable conditions due to the increased energy density of the CMB, and it allows constraints to be placed on the radio …
Characterizing the companion AGBs using surface chemical composition of barium stars
Masseron, Thomas; Shejeelammal, J.; Goswami, Aruna +2 more
Barium stars are one of the important probes to understand the origin and evolution of slow neutron-capture process elements in the Galaxy. These are extrinsic stars, where the observed s-process element abundances are believed to have an origin in the now invisible companions that produced these elements at their asymptotic giant branch (AGB) pha…
NIR counterparts to ULXs (III): completing the photometric survey and selected spectroscopic results
Harrison, F. A.; Roberts, T. P.; Torres, M. A. P. +5 more
We present results from the remaining sources in our search for near-infrared (NIR) candidate counterparts to ultraluminous X-ray sources (ULXs) within ≃10 Mpc. We observed 23 ULXs in 15 galaxies and detected NIR candidate counterparts to 6 of them. Two of these have an absolute magnitude consistent with a single red supergiant (RSG). Three counte…