Search Publications
Period spacings of γ Doradus pulsators in the Kepler field: Rossby and gravity modes in 82 stars
Li, Gang; Bedding, Timothy R.; Antoci, Victoria +2 more
Rossby modes are the oscillations in a rotating fluid, whose restoring force is the Coriolis force. They provide an additional diagnostic to understand the rotation of stars, which complicates asteroseismic modelling. We report 82 γ Doradus stars for which clear period spacing patterns of both gravity and Rossby modes have been detected. The perio…
The non-uniformity of galaxy cluster metallicity profiles
Lovisari, L.; Reiprich, T. H.
We study a sample of 207 nearby galaxy groups and clusters observed with XMM-Newton. Key aspects of this sample include the large size, the high data quality, and the large diversity of cluster dynamical states. We determine the overall metallicity within 0.3 R500 and the radial distribution of the metals. On average, we find a mild dep…
Emergence of the Gaia phase space spirals from bending waves
Widrow, Lawrence M.; Darling, Keir
We discuss the physical mechanism by which pure vertical bending waves in a stellar disc evolve to form phase space spirals similar to those discovered by Antoja et al. in Gaia Data Release 2. These spirals are found by projecting Solar Neighbourhood stars on to the z-vz plane. Faint spirals appear in the number density of stars project…
On the nature and physical conditions of the luminous Ly α emitter CR7 and its rest-frame UV components
Ferrara, Andrea; Schaerer, Daniel; Sobral, David +6 more
We present new Hubble Space Telescope (HST)/WFC3 observations and re-analyse VLT data to unveil the continuum, variability, and rest-frame ultraviolet (UV) lines of the multiple UV clumps of the most luminous Ly α emitter at z = 6.6, CR7 (COSMOS Redshift 7). Our re-reduced, flux-calibrated X-SHOOTER spectra of CR7 reveal an He II emission line in …
Testing modified gravity with wide binaries in Gaia DR2
Sutherland, Will; Pittordis, Charalambos
Several recent studies have shown that very wide binary stars can potentially provide an interesting test for modified-gravity theories which attempt to emulate dark matter; these systems should be almost Newtonian according to standard dark-matter theories, while the predictions for MOND-like theories are distinctly different, if the various obse…
A new, clean catalogue of extragalactic non-nuclear X-ray sources in nearby galaxies
Earnshaw, H. P.; Roberts, T. P.; Mateos, S. +2 more
We have created a new, clean catalogue of extragalactic non-nuclear X-ray sources by correlating the 3XMM-DR4 data release of the XMM-Newton Serendipitous Source Catalogue with the Third Reference Catalogue of Bright Galaxies and the Catalogue of Neighbouring Galaxies, using an improved version of the method presented in Walton et al. Our catalogu…
Detection of the nearest Jupiter analogue in radial velocity and astrometry data
Janson, Markus; Anglada-Escudé, Guillem; Feng, Fabo +4 more
The presence of Jupiter is crucial to the architecture of the Solar system and models underline this to be a generic feature of planetary systems. We find the detection of the difference between the position and motion recorded by the contemporary astrometric satellite Gaia and its precursor Hipparcos can be used to discover Jupiter-like planets. …
Star cluster catalogues for the LEGUS dwarf galaxies
Schaerer, D.; Östlin, G.; Herrero, A. +62 more
We present the star cluster catalogues for 17 dwarf and irregular galaxies in the HST Treasury Program `Legacy ExtraGalactic UV Survey' (LEGUS). Cluster identification and photometry in this sub-sample are similar to that of the entire LEGUS sample, but special methods were developed to provide robust catalogues with accurate fluxes due to low clu…
Contact binaries at the short period cut-off - I. Statistics and the first photometric investigations of 10 totally eclipsing systems
Li, Kai; Xia, Qi-Qi; Gao, Xing +5 more
The period distribution of contact binaries exhibits a very sharp short period cut-off at 0.22 d. In order to provide valuable information on this short period limit, we observed 10 totally eclipsing contact binaries with orbital periods near this cut-off. By detailed analysis using the W-D code, we determined that two of these systems are A-subty…
Assessing the effect of lens mass model in cosmological application with updated galaxy-scale strong gravitational lensing sample
Shu, Yiping; Cao, Xiaoyue; Chen, Yun +1 more
By comparing the dynamical and lensing masses of early-type lens galaxies, one can constrain both the cosmological parameters and the density profiles of galaxies. We explore the constraining power on cosmological parameters and the effect of the lens mass model in this method with 161 galaxy-scale strong lensing systems, which is currently the la…