Search Publications
The frequency of gaseous debris discs around white dwarfs
Hollands, Mark; Pelisoli, Ingrid; Breedt, Elmé +5 more
A total of 1-3 per cent of white dwarfs are orbited by planetary dusty debris detectable as infrared emission in excess above the white dwarf flux. In a rare subset of these systems, a gaseous disc component is also detected via emission lines of the Ca II 8600 Å triplet, broadened by the Keplerian velocity of the disc. We present the first statis…
A large catalogue of molecular clouds with accurate distances within 4 kpc of the Galactic disc
Wang, H. -F.; Huang, Y.; Chen, B. -Q. +6 more
We present a large, homogeneous catalogue of molecular clouds within 4 kpc from the Sun at low Galactic latitudes (|b| < 10°) with unprecedented accurate distance determinations. Based on the 3D dust reddening map and estimates of colour excesses and distances of over 32 million stars presented in Chen et al., we have identified 567 dust/molecu…
MUSE Analysis of Gas around Galaxies (MAGG) - I: Survey design and the environment of a near pristine gas cloud at z ≈ 3.5
Prochaska, J. Xavier; Lusso, Elisabeta; Murphy, Michael T. +9 more
We present the design, methods, and first results of the MUSE Analysis of Gas around Galaxies (MAGG) survey, a large programme on the Multi-Unit Spectroscopic Explorer (MUSE) instrument at the Very Large Telescope (VLT), which targets 28 z > 3.2 quasars to investigate the connection between optically thick gas and galaxies at z ∼ 3-4. MAGG maps…
Evidence for reduced magnetic braking in polars from binary population models
Gänsicke, Boris T.; Belloni, Diogo; Pala, Anna F. +3 more
We present the first population synthesis of synchronous magnetic cataclysmic variables, called polars, taking into account the effect of the white dwarf (WD) magnetic field on angular momentum loss. We implemented the reduced magnetic braking (MB) model proposed by Li, Wu & Wickramasinghe into the Binary Stellar Evolution (BSE) code recently …
To TDE or not to TDE: the luminous transient ASASSN-18jd with TDE-like and AGN-like qualities
Gromadzki, M.; Kochanek, C. S.; Foley, R. J. +26 more
We present the discovery of ASASSN-18jd (AT 2018bcb), a luminous optical/ultraviolet(UV)/X-ray transient located in the nucleus of the galaxy 2MASX J22434289-1659083 at z = 0.1192. Over the year after discovery, Swift UltraViolet and Optical Telescope (UVOT) photometry shows the UV spectral energy distribution of the transient to be well modelled …
Fundamental parameters for 45 open clusters with Gaia DR2, an improved extinction correction and a metallicity gradient prior
Cantat-Gaudin, T.; Moitinho, A.; Paunzen, E. +4 more
Reliable fundamental parameters of open clusters (OCs) such as distance, age, and extinction are key to our understanding of Galactic structure and stellar evolution. In this work, we use Gaia Data Release 2 (DR2) to investigate 45 OCs listed in the New catalogue of optically visible open clusters and candidates (DAML) but with no previous astrome…
Are inner disc misalignments common? ALMA reveals an isotropic outer disc inclination distribution for young dipper stars
Tazzari, M.; Williams, J. P.; Ansdell, M. +12 more
Dippers are a common class of young variable star exhibiting day-long dimmings with depths of up to several tens of per cent. A standard explanation is that dippers host nearly edge-on (Id ≈ 70°) protoplanetary discs that allow close-in (<1 au) dust lifted slightly out of the mid-plane to partially occult the star. The identification…
Globular clusters in the inner Galaxy classified from dynamical orbital criteria
Barbuy, Beatriz; Bica, Eduardo; Pérez-Villegas, Angeles +3 more
Globular clusters (GCs) are the most ancient stellar systems in the Milky Way. Therefore, they play a key role in the understanding of the early chemical and dynamical evolution of our Galaxy. Around 40 per cent of them are placed within ∼4 kpc from the Galactic centre. In that region, all Galactic components overlap, making their disentanglement …
The ASAS-SN catalogue of variable stars VI: an all-sky sample of δ Scuti stars
Kochanek, C. S.; Stanek, K. Z.; Thompson, Todd A. +10 more
We characterize an all-sky catalogue of ∼8400 δ Scuti variables in ASAS-SN, which includes ∼3300 new discoveries. Using distances from Gaia DR2, we derive period-luminosity relationships for both the fundamental mode and overtone pulsators in the WJK, V, Gaia DR2 G, J, H, Ks, and W1 bands. We find that the overtone…
Runaway and walkaway stars from the ONC with Gaia DR2
Parker, Richard J.; Schoettler, Christina; de Bruijne, Jos +1 more
Theory predicts that we should find fast, ejected (runaway) stars of all masses around dense, young star-forming regions. N-body simulations show that the number and distribution of these ejected stars could be used to constrain the initial spatial and kinematic substructure of the regions. We search for runaway and slower walkaway stars within 10…