Search Publications
Investigation of dust attenuation and star formation activity in galaxies hosting GRBs
Salvaterra, R.; Buat, V.; Vergani, S. D. +6 more
Context. The gamma-ray bursts hosts (GRBHs) are excellent targets to study the extinction properties of dust and its effects on the global emission of distant galaxies. The dust extinction curve is measured along the GRB afterglow line of sight and the analysis of the spectral energy distribution (SED) of the host galaxy gives access to the global…
Discovery and characterisation of long-period eclipsing binary stars from Kepler K2 campaigns 1, 2, and 3
Maxted, P. F. L.; Hutcheon, R. J.
Context. The Kepler K2 mission now makes it possible to find and study a wider variety of eclipsing binary stars than has been possible to-date, particularly long-period systems with narrow eclipses.
Aims: Our aim is to characterise eclipsing binary stars observed by the Kepler K2 mission with orbital periods longer than P ≈ 5.5 days.
Me…
Gamma-ray observations of Nova Sgr 2015 No. 2 with INTEGRAL
Starrfield, Sumner; Savchenko, Volodymyr; Diehl, Roland +11 more
Context. INTEGRAL observed Nova Sgr 2015 No. 2 (V5668 Sgr) around the time of its optical emission maximum on 21 March 2015. Studies at UV wavelengths showed spectral lines of freshly produced 7Be. This could also be measurable in gamma rays at 478 keV from the decay to 7Li. Novae are also expected to synthesise 22…
K2-265 b: a transiting rocky super-Earth
Bouchy, F.; Deleuil, M.; Kirk, J. +34 more
We report the discovery of the super-Earth K2-265 b detected with K2 photometry. The planet orbits a bright (Vmag = 11.1) star of spectral type G8V with a period of 2.37 days. We obtained high-precision follow-up radial velocity measurements from HARPS, and the joint Bayesian analysis showed that K2-265 b has a radius of 1.71 ± 0.11 R
Constraining the geometry of the nuclear wind in PDS 456 using a novel emission model
Piro, L.; Fiore, F.; Piconcelli, E. +4 more
Context. Outflows from active galactic nuclei (AGN) are often invoked to explain the co-evolution of AGN and their host galaxies, and the scaling relations between the central black hole mass and the bulge velocity dispersion. Nuclear winds are often seen in the X-ray spectra through Fe K shell transitions and some of them are called ultra fast ou…
Metal abundances in hot white dwarfs with signatures of a superionized wind
Rauch, T.; Werner, K.; Kruk, J. W.
About a dozen hot white dwarfs with effective temperatures Teff = 65 000-120 000 K exhibit unusual absorption features in their optical spectra. These objects were tentatively identified as Rydberg lines of ultra-high excited metals in ionization stages v-x, indicating line formation in a dense environment with temperatures near 10…
High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). II. Lucky Imaging results from 2015 and 2016
Surdej, J.; Henning, Th.; Snodgrass, C. +33 more
Context. The formation and dynamical history of hot Jupiters is currently debated, with wide stellar binaries having been suggested as a potential formation pathway. Additionally, contaminating light from both binary companions and unassociated stars can significantly bias the results of planet characterisation studies, but can be corrected for if…
VLBA polarimetric monitoring of 3C 111
Gurwell, M.; Wilms, J.; Kadler, M. +17 more
Context. While studies of large samples of jets of active galactic nuclei (AGN) are important in order to establish a global picture, dedicated single-source studies are an invaluable tool for probing crucial processes within jets on parsec scales. These processes involve in particular the formation and geometry of the jet magnetic field as well a…
Anatomy of the AGN in NGC 5548. IX. Photoionized emission features in the soft X-ray spectra
Kaastra, J. S.; Kriss, G. A.; Bianchi, S. +10 more
The X-ray narrow emission line region (NELR) of the archetypal Seyfert 1 galaxy NGC 5548 has been interpreted as a single-phase photoionized plasma that is absorbed by some of the warm absorber components. This scenario requires those overlaying warm absorber components to have larger distance (to the central engine) than the X-ray NELR, which is …
Unidentified quasars among stationary objects from Gaia DR2
Geier, S.; Fynbo, J. P. U.; Christensen, L. +5 more
Here we apply a technique selecting quasar candidates purely as sources with zero proper motions in the Gaia data release 2 (DR2). We demonstrate that this approach is highly efficient toward high Galactic latitudes with ≲25% contamination from stellar sources. Such a selection technique offers very pure sample completeness, since all cosmological…