Search Publications
Photometric survey, modelling, and scaling of long-period and low-amplitude asteroids
Geier, S.; Siwak, M.; Cikota, A. +40 more
Context. The available set of spin and shape modelled asteroids is strongly biased against slowly rotating targets and those with low lightcurve amplitudes. This is due to the observing selection effects. As a consequence, the current picture of asteroid spin axis distribution, rotation rates, radiometric properties, or aspects related to the obje…
The infant bow shock: a new frontier at a weak activity comet
Simon Wedlund, Cyril; Nilsson, Hans; Goetz, Charlotte +6 more
The bow shock is the first boundary the solar wind encounters as it approaches planets or comets. The Rosetta spacecraft was able to observe the formation of a bow shock by following comet 67P/Churyumov-Gerasimenko toward the Sun, through perihelion, and back outward again. The spacecraft crossed the newly formed bow shock several times during two…
The completeness-corrected rate of stellar encounters with the Sun from the first Gaia data release
Bailer-Jones, C. A. L.
I report on close encounters of stars to the Sun found in the first Gaia data release (GDR1). Combining Gaia astrometry with radial velocities of around 320 000 stars drawn from various catalogues, I integrate orbits in a Galactic potential to identify those stars which pass within a few parsecs. Such encounters could influence the solar system, f…
Host galaxies of SNe Ic-BL with and without long gamma-ray bursts
Salvaterra, R.; Kaper, L.; Renzo, M. +5 more
Broad-line Ic supernovae (SNe Ic-BL) are a very rare class of core-collapse supernovae exhibiting high ejecta velocities and high kinetic energies. They are the only type of SNe that accompany long gamma-ray burst (GRB) explosions. Systematic differences found in the spectra of SNe Ic-BL with and without GRBs (GRB-SNe and SNe Ic-BL, respectively) …
The envelope of the power spectra of over a thousand δ Scuti stars. The T̅eff - νmax scaling relation
García, R. A.; Roca Cortés, T.; Barceló Forteza, S.
CoRoT and Kepler high-precision photometric data allowed the detection and characterization of the oscillation parameters in stars other than the Sun. Moreover, thanks to the scaling relations, it is possible to estimate masses and radii for thousands of solar-type oscillating stars. Recently, a Δν - ρ relation has been found for δ Scuti stars. No…
Size of a plasma cloud matters. The polarisation electric field of a small-scale comet ionosphere
Gunell, H.; Behar, E.; Nilsson, H. +7 more
Context. The cometary ionosphere is immersed in fast flowing solar wind. A polarisation electric field may arise for comets much smaller than the gyroradius of pickup ions because ions and electrons respond differently to the solar wind electric field.
Aims: A situation similar to that found at a low activity comet has been modelled for bariu…
Resolving faint structures in the debris disk around TWA 7. Tentative detections of an outer belt, a spiral arm, and a dusty cloud
Pinte, C.; Ménard, F.; Augereau, J. -C. +51 more
Context. Debris disks are the intrinsic by-products of the star and planet formation processes. Most likely due to instrumental limitations and their natural faintness, little is known about debris disks around low mass stars, especially when it comes to spatially resolved observations.
Aims: We present new VLT/SPHERE IRDIS dual-polarization …
Evidence of a truncated spectrum in the angular correlation function of the cosmic microwave background
López-Corredoira, M.; Melia, F.
Aim. The lack of large-angle correlations in the fluctuations of the cosmic microwave background (CMB) conflicts with predictions of slow-roll inflation. But while probabilities (≲0.24%) for the missing correlations disfavour the conventional picture at ≳3σ, factors not associated with the model itself may be contributing to the tension. Here we a…
KMOS LENsing Survey (KLENS): Morpho-kinematic analysis of star-forming galaxies at z 2
Schaerer, D.; Dessauges-Zavadsky, M.; Cava, A. +6 more
We present results from the KMOS LENsing Survey (KLENS), which is exploiting gravitational lensing to study the kinematics of 24 star-forming galaxies at 1.4 < z < 3.5 with a median mass of log(M⋆/M⊙) = 9.6 and a median star formation rate (SFR) of 7.5 M⊙ yr-1. We find that 25% of these low mass/lo…
Improving dynamical mass constraints for intermediate-period substellar companions using Gaia DR2
Calissendorff, Per; Janson, Markus
The relationship between luminosity and mass is of fundamental importance for direct imaging studies of brown dwarf and planetary companions to stars. In principle this can be inferred from theoretical mass-luminosity models; however, these relations have not yet been thoroughly calibrated, since there is a lack of substellar companions for which …