Search Publications
A recent confirmation of the wide binary gravitational anomaly
Kroupa, Pavel; Hernandez, X.
Concerning recent published studies exploring the presence or otherwise of a gravitational anomaly at low accelerations in wide binary stars as observed by the Gaia satellite, the paper published by Cookson on the subject last year presents an interesting case. In that study, RMS values of binned relative internal one-dimensional velocities for wi…
Detection and characterization of giant planets with Gaia astrometry
Castro-Ginard, A.; Brown, A. G. A.; Casey, A. R. +1 more
Astrometric observations with Gaia are expected to play a valuable role in future exoplanet surveys. With current data from Gaia's third data release (DR3), we are sensitive to periods from less than 1 yr to more than 4 yr but, unlike radial velocity (R.V.) are not as restricted by the orbital inclination of a potential planet. The presence and po…
Broad-line active galactic nuclei in the 6dF Galaxy Survey
Wolf, Christian; Hon, Wei Jeat; Webster, Rachel L.
The Six-degree Field Galaxy Survey (6dFGS) is a spectroscopic redshift survey of the Southern hemisphere completed in 2006. While it provides 136 304 spectra of mostly low-redshift galaxies, a large and reliable catalogue of active galactic nuclei (AGNs) that are selected based on spectral signatures is still lacking. In this work, we present an e…
Quasi-periodic eruptions as Lense-Thirring precession of super-Eddington flows
Pinto, C.; Miniutti, G.; Dauser, T. +9 more
Quasi-periodic eruptions (QPEs) are a recently identified class of X-ray transient associated with tidal disruption events by supermassive black holes, and for which there are multiple possible explanations. In this paper, we present a simple model which requires the black hole be spinning, be misaligned with the accretion flow (both conditions of…
I Zw 1 and H0557-385: the dusty tori of two high Eddington AGNs observed in the MATISSE LM bands
Kishimoto, Makoto; Drewes, Farin; Leftley, James H. +2 more
The torus in active galactic nuclei (AGNs) is a complex dynamical structure of gas and dust. It is thought to be composed of an equatorial dusty disc and a polar dusty wind launched by radiation pressure. However, this picture is based on studies of moderately accreting AGN. Models suggest that the disc/wind structure will change with specific acc…
Detecting eclipsing double white dwarfs with electromagnetic and gravitational waves
Shao, Yong; Ma, Bo; Wang, Yan +1 more
Galactic double white dwarfs (DWDs) are predominant sources of gravitational waves in the millihertz frequencies accessible to space-borne gravitational wave (GW) detectors. With advances in multimessenger astronomy, an increasing number of DWD systems will be discovered through both electromagnetic (EM) and GW observations. In this paper, we simu…
X-ray AGN in Boötes: the lack of growth of the most massive black holes since z = 4
Aird, James; Terrazas, Bryan A.; Coil, Alison L. +5 more
Supermassive black holes (BHs) are known to efficiently grow through gas accretion, but even sustained and intense mass build-up through this mechanism struggles to explain the assembly of the most massive BHs observed in the local Universe. Using the Chandra Deep-Wide Field Survey (CDFWS) in the Boötes field, we measure BH-galaxy assembly in mass…
Predicting metallicities and carbon abundances from Gaia XP spectra for (carbon-enhanced) metal-poor stars
Belokurov, Vasily; Monty, Stephanie; Ardern-Arentsen, Anke +4 more
Carbon-rich (C-rich) stars can be found at all metallicities and evolutionary stages. They are often the result of mass transfer from a companion, but some of the most metal-poor C-rich objects are likely carrying the imprint of the metal-free First Stars from birth. In this work, we employ a neural network to predict metallicities and carbon abun…
The First Spin-Orbit Obliquity of an M dwarf/brown dwarf system: an eccentric and aligned TOI-2119 b
Cegla, Heather M.; Mahadevan, Suvrath; Bayliss, Daniel +15 more
We report the first instance of an M dwarf/brown dwarf obliquity measurement for the TOI-2119 system using the Rossiter-McLaughlin effect. TOI-2119 b is a transiting brown dwarf orbiting a young, active early M dwarf (
Modelling the density and mass of the Milky Way's proto-galaxy components with APOGEE-Gaia
Horta, Danny; Schiavon, Ricardo P.
Unravelling galaxy formation theory requires understanding galaxies both at high and low redshifts. A possible way to connect both realms is by studying the oldest stars in the Milky Way (i.e. the proto-Galaxy). We use the APOGEE-Gaia surveys to perform a purely chemical dissection of Milky Way (MW) stellar populations, and identify samples of sta…