Search Publications
ALMA observations of the early stages of substellar formation in the Lupus 1 and 3 molecular clouds
Hales, A.; de Gregorio-Monsalvo, I.; Bayo, A. +10 more
Context. The dominant mechanism leading to the formation of brown dwarfs (BDs) remains uncertain. While the census of Class II analogs in the substellar domain continues to grow, the most direct keys to formation, which are obtained from younger objects (pre-BD cores and proto-BDs), are limited by the very low number statistics available.
Aim…
Multi-wavelength VLTI study of the puffed-up inner rim of a circumbinary disc
Min, M.; Van Winckel, H.; Kamath, D. +3 more
Context. The presence of stable, compact circumbinary discs of gas and dust around post-asymptotic giant branch (post-AGB) binary systems has been well established. We focus on one such system, IRAS 08544−4431.
Aims: We present an interferometric multi-wavelength analysis of the circumstellar environment of IRAS 08544−4431. The aim is to cons…
On the size distribution of spots within sunspot groups
Solanki, Sami K.; Krivova, Natalie A.; Mandal, Sudip +1 more
The size distribution of sunspots provides key information about the generation and emergence processes of the solar magnetic field. Previous studies of size distribution have primarily focused on either the whole group or individual spot areas. In this paper we investigate the organisation of spot areas within sunspot groups. In particular, we an…
Small lobe of comet 67P: Characterization of the Wosret region with ROSETTA-OSIRIS
Sierks, H.; Barucci, M. A.; Fornasier, S. +3 more
Aims: We investigated Wosret, a region located on the small lobe of the 67P/Churyumov-Gerasimenko comet subject to strong heating during the perihelion passage. This region includes the two last landing sites of the Philae lander as well as, notably the final one, Abydos, where the lander performed most of its measurements. We study Wosret in…
G 112-43/44: A metal-poor binary star with a unique chemical composition and Helmi stream kinematics
Nissen, P. E.; Schuster, W. J.; Silva-Cabrera, J. S.
Context. Correlations between high-precision elemental abundance ratios and the kinematics of halo stars provide interesting information about the formation and early evolution of the Galaxy.
Aims: Element abundances of G 112-43/44, a metal-poor wide-orbit binary star with extreme kinematics, are revisited.
Methods: High-precision studie…
Multiwavelength observations of a metric type-II event
Hillaris, A.; Patsourakos, S.; Nindos, A. +1 more
We have studied a complex metric radio event that originated in a compact flare, observed with the ARTEMIS-JLS radiospectrograph on February 12, 2010. The event was associated with a surge observed at 195 and 304 Å and with a coronal mass ejection observed by instruments on board STEREO A and B near the eastern and western limbs respectively. On t…
Spectral state transitions in Circinus ULX5
Markowitz, Alex; Mondal, Samaresh; De Marco, Barbara +2 more
Context. We performed timing and spectral analyses of multi-epoch Suzaku, XMM-Newton, and NuSTAR observations of the ultraluminous X-ray source (ULX) Circinus ULX5 with the aim of putting constraints on the mass of the central object and the accretion mode operating in this source.
Aims: We investigate whether the source contains a stellar ma…
X-ray emitting structures in the Vela SNR: ejecta anisotropies and progenitor stellar wind residuals
Miceli, M.; Bocchino, F.; Orlando, S. +6 more
Context. The Vela supernova remnant (SNR) shows several ejecta fragments (or shrapnel) protruding beyond the forward shock, which are most likely relics of anisotropies that developed during the supernova (SN) explosion. Recent studies have revealed high Si abundance in two shrapnel (shrapnel A and G), located in opposite directions with respect t…
A detailed understanding of the rotation-activity relationship using the 300 Myr old open cluster NGC 3532
Strassmeier, K. G.; Barnes, S. A.; James, D. J. +2 more
Context. The coeval stars of young open clusters provide insights into the formation of the rotation-activity relationship that elude studies of multi-age field populations.
Aims: We measure the chromospheric activity of cool stars in the 300 Myr old open cluster NGC 3532 in concert with their rotation periods to study the mass-dependent morp…
Using radial velocities to reveal black holes in binaries: A test case
Babusiaux, C.; Dubus, G.; Casares, J. +1 more
Aims: Large radial velocity variations in the LAMOST spectra of giant stars have been used to infer the presence of unseen companions. Some of them have been proposed as possible black hole candidates. We test this selection by investigating the classification of the one candidate that has a known X-ray counterpart (UCAC4 721-037069).
Me…