Search Publications
ESPRESSO highlights the binary nature of the ultra-metal-poor giant HE 0107-5240
Rebolo, R.; Allende Prieto, C.; Bonifacio, P. +29 more
Context. The vast majority of the known stars of ultra low metallicity ([Fe/H] < -4.5) are known to be enhanced in carbon, and belong to the "low-carbon band" (A(C) = log(C/H)+12 ≤ 7.6). It is generally, although not universally, accepted that this peculiar chemical composition reflects the chemical composition of the gas cloud out of which the…
Dust and star formation in the centre of NGC 3311
Hilker, M.; Richtler, T.; Barbosa, C. E. +1 more
Context. NGC 3311 is the central galaxy of the Hydra I galaxy cluster. It has a hot interstellar medium and hosts a central dust lane with emission lines. These dust lanes are frequent in elliptical galaxies, but the case of NGC 3311 might be particularly interesting for problems of dust lifetime and the role of cool gas in the central parts.
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X-raying winds in distant quasars: The first high-redshift wind duty cycle
Cappi, M.; Vignali, C.; Dadina, M. +6 more
Aims: Theoretical models of wind-driven feedback from active galactic nuclei (AGN) often identify ultra-fast outflows as being the main agent in the generation of galaxy-sized outflows, which are possibly the main actors in establishing so-called AGN-galaxy co-evolution. Ultra-fast outflows are well characterized in local AGN but much less is…
Search for the sub-stellar lithium depletion boundary in the open star cluster Coma Berenices
Béjar, V. J. S.; Martín, E. L.; Lodieu, N.
Aims: We mainly aim to search for the lithium depletion boundary (LDB) among the sub-stellar population of the open star cluster Coma Berenices.
Methods: Since the number of brown dwarf candidates in Coma Ber available in the literature is scarce, we carried out a search for additional candidates photometrically using colour-magnitude di…
Search for He I airglow emission from the hot Jupiter τ Boo b
Zhang, Yapeng; Alonso-Floriano, F. J.; Snellen, I. A. G. +4 more
Context. It has been suggested that the helium absorption line at 10 830 Å that originates from the metastable triplet state 23S is an excellent probe for the extended atmospheres of hot Jupiters and their hydrodynamic escape processes. It has recently been detected in the transmission spectra of a handful of planets. The isotropic reem…
The Northern Extragalactic WISE × Pan-STARRS (NEWS) catalogue. Machine-learning identification of 40 million extragalactic objects
Khramtsov, Vladislav; Akhmetov, Volodymyr; Fedorov, Peter
This study involves two photometric catalogues, AllWISE and Pan-STARRS Data Release 1, which were cross-matched to identify extragalactic objects among the common sources of these catalogues. To separate galaxies and quasars from stars, we created a machine-learning model that is trained on photometric (in fact, colour-based) information from the …
A broadband X-ray view of the NLSy1 1E 0754.6+3928
Bianchi, S.; Petrucci, P. -O.; Miniutti, G. +8 more
Context. The soft X-ray band of many active galactic nuclei (AGNs) is affected by obscuration due to partially ionised matter crossing our line of sight. In this context, two past XMM-Newton observations that were six months apart and a simultaneous NuSTAR-Swift exposure of the Narrow Line Seyfert 1 galaxy 1E 0754.6+3928, which was approximately e…
Dust emission, extinction, and scattering in LDN 1642
Ysard, Nathalie; Juvela, Mika; Neha, Sharma +3 more
Context. LDN 1642 is a rare example of a star-forming, high-latitude molecular cloud. The dust emission of LDN 1642 has already been studied extensively in the past, but its location also makes it a good target for studies of light scattering.
Aims: We wish to study the near-infrared (NIR) light scattering in LDN 1642, its correlation with th…
Gemini-GRACES high-quality spectra of Kepler evolved stars with transiting planets. I. Detailed characterization of multi-planet systems Kepler-278 and Kepler-391
Almenara, J. M.; Díaz, R. F.; Martioli, E. +10 more
Aims: Kepler-278 and Kepler-391 are two of the three evolved stars known to date on the red giant branch (RGB) to host multiple short-period transiting planets. Moreover, the planets orbiting Kepler-278 and Kepler-391 are among the smallest discovered around RGB stars. Here we present a detailed stellar and planetary characterization of these…
Simulations of satellite tidal debris in the Milky Way halo
Just, Andreas; Macciò, Andrea V.; Mazzarini, Matteo +1 more
Aims: We study the distribution of the stellar and dark matter debris of the Milky Way satellites.
Methods: For the first time we address the question of the tidal disruption of satellites in simulations by utilising simultaneously (a) a realistic set of orbits extracted from cosmological simulations; (b) a three-component host galaxy wi…