Search Publications
Star formation in far-IR AGN and non-AGN galaxies in the green valley - II. Morphological analysis
Pović, Mirjana; Väisänen, Petri; Mahoro, Antoine +2 more
This paper studies morphological properties of 103 green valley FIR active and 2609 non-active galaxies presented in Mahoro, Pović & Nkundabakura (2017). The photometric data from the COSMOS survey were used, and the morphological parameters, such as Abraham and Conselice-Bershady concentration indices, Gini, M20 moment of light, and asymmetry…
Chemical analysis of K giants in the young open cluster NGC 2345
Pereira, C. B.; Holanda, N.; Drake, N. A.
We present results for the elemental abundances of five K giants of the young open cluster NGC 2345. The atmospheric parameters of the studied giants and their chemical abundances were determined using high-resolution optical spectroscopy. In this study, we determine abundances of light elements (Li, C, N), light odd-Z elements (Na, Al), α-element…
Detailed study of the Milky Way globular cluster Laevens 3
Martin, Nicolas; Ibata, Rodrigo A.; Mackey, Dougal +4 more
We present a photometric and spectroscopic study of the Milky Way satellite Laevens 3. Using MegaCam/Canada-France-Hawaii Telescope g and i photometry and Keck II/DEIMOS multi-object spectroscopy, we refine the structural and stellar properties of the system. The Laevens 3 colour-magnitude diagram shows that it is quite metal-poor, old (13.0 ± 1.0…
A black box for dark sector physics: predicting dark matter annihilation feedback with conditional GANs
Lewis, Geraint F.; List, Florian; Bhat, Ishaan
Traditionally, incorporating additional physics into existing cosmological simulations requires re-running the cosmological simulation code, which can be computationally expensive. We show that conditional Generative Adversarial Networks (cGANs) can be harnessed to predict how changing the underlying physics alters the simulation results. To illus…
Asteroseismic constraints on active latitudes of solar-type stars: HD 173701 has active bands at higher latitudes than the Sun
Chaplin, William J.; Davies, Guy R.; Miglio, Andrea +6 more
We present a new method for determining the location of active bands of latitude on solar-type stars, which uses stellar-cycle-induced frequency shifts of detectable solar-like oscillations. When near-surface activity is distributed in a non-homogeneous manner, oscillation modes of different angular degree and azimuthal order will have their frequ…
A magnetic white dwarf with five H α components
Bergeron, P.; Kilic, Mukremin; Vanderbosch, Z. +3 more
G183-35 is an unusual white dwarf that shows an H α line split into five components, instead of the usual three components seen in strongly magnetic white dwarfs. Potential explanations for the unusual set of lines include a double degenerate system containing two magnetic white dwarfs and/or rotational modulation of a complex magnetic field struc…
Discovery of recombining plasma inside the extended gamma-ray supernova remnant HB9
Fukui, Y.; Sano, H.; Sezer, A. +2 more
We present the results from the Suzaku X-ray Imaging Spectrometer observation of the mixed-morphology supernova remnant (SNR) HB9 (G160.9+2.6). We discovered recombining plasma (RP) in the western Suzaku observation region and the spectra here are well described by a model having collisional ionization equilibrium (CIE) and RP components. On the o…
Heavy negative ion growth in Titan's polar winter
Coates, A. J.; Jones, G. H.; Wellbrock, A. +4 more
A significant but unexpected result of the Cassini mission was the discovery of heavy organic negative ions in Titan's ionosphere at altitudes between about 950 and 1400 km by the CAPS Electron Spectrometer (ELS). The heaviest ions were observed during the T16 fly-by with masses over 13 000 u/q. This is significantly higher than the maximum masses…
Supergiant Fast X-ray Transients uncovered by the EXTraS project: flares reveal the development of magnetospheric instability in accreting neutron stars
Esposito, Paolo; Belfiore, Andrea; Salvaterra, Ruben +5 more
The low luminosity, X-ray flaring activity, of the sub-class of high-mass X-ray binaries called Supergiant Fast X-ray Transients, has been investigated using XMM-Newton public observations, taking advantage of the products made publicly available by the EXTraS project. One of the goals of EXTraS was to extract from the XMM-Newton public archive in…
The signal of decaying dark matter with hydrodynamical simulations
Lovell, Mark R.; Crain, Robert A.; Schaye, Joop +11 more
Dark matter particles may decay, emitting photons. Drawing on the EAGLE family of hydrodynamical simulations of galaxy formation - including the APOSTLE and C-EAGLE simulations - we assess the systematic uncertainties and scatter on the decay flux from different galaxy classes, from Milky Way satellites to galaxy clusters, and compare our results …