Search Publications
The geometric challenge of testing gravity with wide binaries
El-Badry, Kareem
Wide binaries provide promising laboratories for testing general relativity (GR) in the low-acceleration regime. Recent observational studies have found that the difference in the proper motions and/or radial velocities of the components of nearby wide binaries appear larger than predicted by Kepler's laws, indicating a potential breakdown of GR a…
Helium enrichment in intermediate-age Magellanic Clouds clusters: towards an ubiquity of multiple stellar populations?
Martocchia, S.; Salaris, M.; Bastian, N. +1 more
Intermediate-age star clusters in the Magellanic Clouds harbour signatures of the multiple stellar populations long thought to be restricted to old globular clusters. We compare synthetic horizontal branch models with Hubble Space Telescope photometry of clusters in the Magellanic Clouds, with age between ∼2 and ∼10 Gyr, namely NGC 121, Lindsay 1,…
A new study of the variable star population in the Hercules globular cluster (M13; NGC 6205)
Arellano Ferro, A.; Calderón, J. H.; Lázaro, C. +4 more
We present the results from VI CCD time-series photometry of the globular cluster M13 (NGC 6205). From the Fourier decomposition of the light curves of RRab and RRc stars we found an average metallicity of [Fe/H]zw = -1.58 ± 0.09. The distance to the cluster was estimated as 7.1 ± 0.1 kpc from independent methods related to the variable star famil…
60Fe in core-collapse supernovae and prospects for X-ray and gamma-ray detection in supernova remnants
Safi-Harb, Samar; Fryer, Chris L.; Mumpower, Matthew R. +6 more
We investigate 60Fe in massive stars and core-collapse supernovae focussing on uncertainties that influence its production in 15, 20, and 25 M⊙ stars at solar metallicity. We find that the 60Fe yield is a monotonic increasing function of the uncertain 59Fe(n, γ)60Fe cross-section and that a fa…
WASP-166b: a bloated super-Neptune transiting a V = 9 star
Bouchy, F.; Queloz, D.; Hellier, Coel +21 more
We report the discovery of WASP-166b, a super-Neptune planet with a mass of 0.1 MJup (1.9 MNep) and a bloated radius of 0.63 RJup. It transits a V = 9.36, F9V star in a 5.44-d orbit that is aligned with the stellar rotation axis (sky-projected obliquity angle λ = 3 ± 5 deg). Variations in the radial-velocity measur…
Smoking gun of the dynamical processing of solar-type field binary stars
Liu, Chao
I investigate the binarity properties of field stars using more than 50 000 main-sequence stars with stellar mass from 0.4 to 0.85 M⊙ observed by LAMOST and Gaia in the solar neighbourhood. By adopting a power-law shape for the mass-ratio distribution with a power index of γ, I conduct a hierarchical Bayesian model to derive the binary …
HIDES spectroscopy of bright detached eclipsing binaries from the Kepler field - III. Spectral analysis, updated parameters and new systems
Kambe, E.; Pigulski, A.; Maehara, H. +5 more
We present the latest results of our spectroscopic observations and refined modelling of a sample of detached eclipsing binaries, selected from the Kepler Eclipsing Binary Catalog, that are also double-lined spectroscopic binaries (SB2s). New high-resolution spectra obtained with the HIgh-Dispersion Echelle Spectrograph (HIDES), attached to the 1.…
The O star hinterland of the Galactic starburst, NGC 3603
Monguió, M.; Wright, N. J.; Drew, J. E.
The very bright and compact massive young cluster, NGC 3603, has been cited as an example of a starburst in the Milky Way and compared with the much-studied R136/30 Doradus region in the Large Magellanic Cloud. Here we build on the discovery by Mohr-Smith et al. of a large number of reddened O stars around this cluster. We construct a list of 288 …
Tracking the variable jets of V404 Cygni during its 2015 outburst
Altamirano, D.; Bremer, M.; Russell, D. M. +14 more
We present multifrequency monitoring observations of the black hole X-ray binary V404 Cygni throughout its 2015 June outburst. Our data set includes radio and mm/sub-mm photometry, taken with the Karl G. Jansky Very Large Array, Arc-Minute MicroKelvin Imager Large Array, Sub-millimeter Array, James Clerk Maxwell Telescope, and the Northern Extende…
Physical properties of the X-ray gas as a dynamical diagnosis for galaxy clusters
Durret, F.; Lopes, P. A. A.; Laganá, T. F.
We analysed XMM-Newton EPIC data for 53 galaxy clusters. Through 2D spectral maps, we provide the most detailed and extended view of the spatial distribution of temperature (kT), pressure (P), entropy (S), and metallicity (Z) of galaxy clusters to date with the aim of correlating the dynamical state of the system to six cool-core (CC) diagnoses fr…