Search Publications
Five young δ Scuti stars in the Pleiades seen with Kepler/K2
Li, Yaguang; Bedding, Timothy R.; White, Timothy R. +4 more
We perform mode identification for five δ Scuti stars in the Pleiades star cluster, using custom light curves from K2 photometry. By creating échelle diagrams, we identify radial and dipole mode ridges, comprising a total of 28 radial and 16 dipole modes across the five stars. We also suggest possible identities for those modes that lie offset fro…
Stellar and black hole assembly in z < 0.3 infrared-luminous mergers: intermittent starbursts versus super-Eddington accretion
Lebouteiller, Vianney; Pearson, Chris; Clements, David L. +20 more
We study stellar and black hole mass assembly in a sample of 42 infrared-luminous galaxy mergers at z < 0.3 by combining results from radiative transfer modelling with archival measures of molecular gas and black hole mass. The ratios of stellar mass, molecular gas mass, and black hole mass to each other are consistent with those of massive gas…
Improving blazar redshift constraints with the edge of the Ly α forest: 1ES 1553+113 and implications for observations of the WHIM
Narayanan, A.; Sameer; Charlton, J. +6 more
Blazars are some of the brightest ultraviolet (UV) and X-ray sources in the sky and are valuable probes of the elusive warm-hot intergalactic medium (WHIM; T ≃ 105-107 K). However, many of the brightest blazars - called BL Lac objects such as 1ES 1553+113 - have quasi-featureless spectra and poorly constrained redshifts. Here…
The value-added catalogue of ASAS-SN eclipsing binaries: parameters of 30 000 detached systems
Kochanek, C. S.; Stanek, K. Z.; Thompson, Todd A. +6 more
Detached eclipsing binaries are a fundamental tool for measuring the physical parameters of stars that are effectively evolving in isolation. Starting from more than 40 000 eclipsing binary candidates identified by the All-Sky Automated Survey for Supernovae (ASAS-SN), we use PHOEBE to determine the sum of the fractional radii, the ratio of effect…
Chromosome maps of globular clusters from wide-field ground-based photometry
Milone, A. P.; Cordoni, G.; Marino, A. F. +10 more
Hubble Space Telescope (HST) photometry is providing an extensive analysis of globular clusters (GCs). In particular, the pseudo-two-colour diagram dubbed 'chromosome map (ChM)' allowed to detect and characterize their multiple populations with unprecedented detail. The main limitation of these studies is the small field of view of HST, which make…
The white dwarf binary pathways survey - VIII. A post-common envelope binary with a massive white dwarf and an active G-type secondary star
Gänsicke, B. T.; Rebassa-Mansergas, A.; Raddi, R. +6 more
The white dwarf binary pathways survey is dedicated to studying the origin and evolution of binaries containing a white dwarf and an intermediate-mass secondary star of the spectral type A, F, G, or K (WD + AFGK). Here, we present CPD-65 264, a new post-common envelope binary with an orbital period of 1.37 d that contains a massive white dwarf ($0…
Eclipsing white dwarf binaries in Gaia and the Zwicky Transient Facility
Belokurov, Vasily; Breedt, Elmé; Hodgkin, Simon +4 more
Gaia provided the largest ever catalogue of white dwarf stars. We use this catalogue, along with the third public data release of the Zwicky Transient Facility (ZTF), to identify new eclipsing white dwarf binaries. Our method exploits light-curve statistics and the box least-squares algorithm to detect periodic light-curve variability. The search …
Linking chromospheric activity and magnetic field properties for late-type dwarf stars
Petit, P.; Vidotto, A. A.; Jeffers, S. V. +9 more
Spectropolarimetric data allow for simultaneous monitoring of stellar chromospheric $\log {R^{\prime }_{\rm {HK}}}$ activity and the surface-averaged longitudinal magnetic field, Bl, giving the opportunity to probe the relationship between large-scale stellar magnetic fields and chromospheric manifestations of magnetism. We present $\lo…
Deriving ages and horizontal branch properties of integrated stellar populations
Conroy, Charlie; Cabrera-Ziri, Ivan
A major source of uncertainty in the age determination of old (~10 Gyr) integrated stellar populations is the presence of hot horizontal branch (HB) stars. Here, we describe a simple approach to tackle this problem, and show the performance of this technique that simultaneously models the age, abundances, and HB properties of integrated stellar po…
Seismic modelling of a very young SPB star - KIC 8264293
Walczak, Przemysław; Moździerski, Dawid; Daszyńska-Daszkiewicz, Jadwiga +1 more
KIC 8264293 is a fast-rotating B-type pulsator observed by Kepler satellite. Its photometric variability is mainly due to pulsations in high-order g modes. Besides, we detected a weak Hα emission. Thus, the second source of variability is the fluctuation in a disc around the star. The pulsational spectrum of KIC 8264293 reveals a frequency groupin…