Search Publications
Galactic evolution of copper in the light of NLTE computations
Bonifacio, P.; Caffau, E.; Korotin, S. +5 more
We have developed a model atom for Cu with which we perform statistical equilibrium computations that allow us to compute the line formation of Cu I lines in stellar atmospheres without assuming local thermodynamic equilibrium (LTE). We validate this model atom by reproducing the observed line profiles of the Sun, Procyon and 11 metal-poor stars. …
Testing the X-ray reverberation model KYNREFREV in a sample of Seyfert 1 Active Galactic Nuclei
Papadakis, I. E.; Dovčiak, M.; Karas, V. +4 more
We present the first results obtained by the application of the KYNREFREV-reverberation model, which is ready for its use in XSPEC. This model computes the time-dependent reflection spectra of the disc as a response to a flash of primary power-law radiation from a point source corona located on the axis of the black hole accretion disc (lamp-post …
X-ray study of a sample of FR0 radio galaxies: unveiling the nature of the central engine
Capetti, A.; Grandi, P.; Torresi, E. +2 more
Fanaroff-Riley type 0 radio galaxies (FR0s) are compact radio sources that represent the bulk of the radio-loud active galactic nuclei (AGN) population, but they are still poorly understood. Pilot studies on these sources have been already performed at radio and optical wavelengths: here we present the first X-ray study of a sample of 19 FR0 radio…
KiDS-SQuaD: The KiDS Strongly lensed Quasar Detection project
Koopmans, L. V. E.; Capaccioli, M.; Napolitano, N. R. +11 more
New methods have recently been developed to search for strong gravitational lenses, in particular lensed quasars, in wide-field imaging surveys. Here, we compare the performance of three different, morphology- and photometry-based methods to find lens candidates within the Kilo-Degree Survey (KiDS) DR3 footprint (440 deg2). The three me…
HERUS: the far-IR/submm spectral energy distributions of local ULIRGs and photometric atlas
Clements, D. L.; Farrah, D.; Rigopoulou, D. +9 more
We present the Herschel-SPIRE photometric atlas for a complete flux limited sample of 43 local ultraluminous infrared galaxies (ULIRGs), selected at 60 µm by IRAS, as part of the HERschel ULIRG Survey (HERUS). Photometry observations were obtained using the SPIRE instrument at 250, 350, and 500 µm. We describe these observations, prese…
The fall of the Northern Unicorn: tangential motions in the Galactic anticentre with SDSS and Gaia
Belokurov, V.; Koposov, S. E.; de Boer, T. J. L.
We present the first detailed study of the behaviour of the stellar proper motion across the entire Galactic anticentre area visible in the Sloan Digital Sky Survey (SDSS) data. We use recalibrated SDSS astrometry in combination with positions from Gaia DR1 to provide tangential motion measurements with a systematic uncertainty <5 km s-1
Pulsation-triggered dust production by asymptotic giant branch stars
Zijlstra, A. A.; De Beck, E.; McDonald, I. +1 more
Eleven nearby (<300 pc), short-period (50-130 d) asymptotic giant branch (AGB) stars were observed in the CO J = 2-1 line. Detections were made towards objects that have evidence for dust production (Ks - [22] ≳ 0.55 mag; AK Hya, V744 Cen, RU Crt, α Her). Stars below this limit were not detected (BQ Gem, ɛ Oct, NU Pav, II Hya, CL Hyi…
Resolving the kinematics of the discs around Galactic B[e] supergiants
Vasilopoulos, G.; Borges Fernandes, M.; Kraus, M. +4 more
B[e] supergiants are luminous evolved massive stars. The mass-loss during this phase creates a complex circumstellar environment with atomic, molecular, and dusty regions usually found in rings or disc-like structures. For a better comprehension of the mechanisms behind the formation of these rings, detailed knowledge about their structure and dyn…
Anatomy of the hyper-runaway star LP 40-365 with Gaia
Hermes, J. J.; Gänsicke, B. T.; Hollands, M. A. +4 more
LP 40-365 (aka GD 492) is a nearby low-luminosity hyper-runaway star with an extremely unusual atmospheric composition, which has been proposed as the remnant of a white dwarf that survived a peculiar Type Iax supernova (SN Iax) in a single-degenerate scenario. Adopting the Gaia Data Release 2 (DR2) parallax, ϖ = 1.58 ± 0.03 mas, we estimate a rad…
High-contrast imaging of HD 163296 with the Keck/NIRC2 L'-band vortex coronograph
Absil, O.; Guidi, G.; Testi, L. +16 more
We present observations of the nearby (D∼100 pc) Herbig star HD 163296 taken with the vortex coronograph at Keck/NIRC2 in the L' band (3.7 µm) to search for planetary mass companions in the ringed disc surrounding this pre-main-sequence star. The images reveal an arc-like region of scattered light from the disc surface layers that is likely …