Search Publications
Latest astronomical constraints on some non-linear parametric dark energy models
Yang, Weiqiang; Pan, Supriya; Paliathanasis, Andronikos
We consider non-linear redshift-dependent equation of state parameters as dark energy models in a spatially flat Friedmann-Lemaître-Robertson-Walker universe. To depict the expansion history of the universe in such cosmological scenarios, we take into account the large-scale behaviour of such parametric models and fit them using a set of latest ob…
Debris disc constraints on planetesimal formation
Blum, Jürgen; Krivov, Alexander V.; Löhne, Torsten +2 more
Two basic routes for planetesimal formation have been proposed over the last decades. One is a classical `slow-growth' scenario. Another one is particle concentration models, in which small pebbles are concentrated locally and then collapse gravitationally to form planetesimals. Both types of models make certain predictions for the size spectrum a…
A free-form lensing model of A370 revealing stellar mass dominated BCGs, in Hubble Frontier Fields images
Schmidt, Kasper B.; Broadhurst, Tom; Zheng, Wei +9 more
We derive a free-form mass distribution for the unrelaxed cluster A370 (z = 0.375), using the first release of the Hubble Frontier Fields images (76 orbits) and GLASS spectroscopy. Starting from a reliable set of 10 multiply lensed systems, we produce a free-form lens model that identifies ≈80 multiple images. Good consistency is found between mod…
JINGLE, a JCMT legacy survey of dust and gas for galaxy evolution studies - I. Survey overview and first results
Lamperti, Isabella; Saintonge, Amélie; Ho, Luis C. +88 more
JINGLE is a new JCMT legacy survey designed to systematically study the cold interstellar medium of galaxies in the local Universe. As part of the survey we perform 850 µm continuum measurements with SCUBA-2 for a representative sample of 193 Herschel-selected galaxies with M* > 109 M⊙, as well as integrated CO(…
Magnetism, X-rays and accretion rates in WD 1145+017 and other polluted white dwarf systems
Gänsicke, B. T.; Fossati, L.; Redfield, S. +9 more
This paper reports circular spectropolarimetry and X-ray observations of several polluted white dwarfs including WD 1145+017, with the aim to constrain the behaviour of disc material and instantaneous accretion rates in these evolved planetary systems. Two stars with previously observed Zeeman splitting, WD 0322-019 and WD 2105-820, are detected a…
The stellar population and initial mass function of NGC 1399 with MUSE
Davies, Roger L.; Houghton, Ryan C. W.; Vaughan, Sam P. +1 more
We present spatially resolved measurements of the stellar initial mass function (IMF) in NGC 1399, the largest elliptical galaxy in the Fornax Cluster. Using data from the Multi Unit Spectroscopic Explorer (MUSE) and updated state-of-the-art stellar population synthesis models from Conroy et al., we use full spectral fitting to measure the low-mas…
Discovery of synchronous X-ray and radio moding of PSR B0823+26
Tiburzi, C.; Grießmeier, J. -M.; Serylak, M. +10 more
Simultaneous observations of PSR B0823+26 with ESA's XMM-Newton, the Giant Metrewave Radio Telescope and international stations of the Low Frequency Array revealed synchronous X-ray/radio switching between a radio-bright (B) mode and a radio-quiet (Q) mode. During the B mode we detected PSR B0823+26 in 0.2 - 2 keV X-rays and discovered pulsed emis…
A likely planet-induced gap in the disc around T Cha
Pascucci, Ilaria; Henning, Thomas; Dong, Ruobing +7 more
We present high-resolution (0.11 × 0.06 arcsec2) 3 mm ALMA observations of the highly inclined transition disc around the star T Cha. Our continuum image reveals multiple dust structures: an inner disc, a spatially resolved dust gap, and an outer ring. When fitting sky-brightness models to the real component of the 3 mm visibilities, we…
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 …