Search Publications
Exploring the structure and kinematics of the Milky Way through A stars
Monguió, M.; Figueras, F.; Carrasco, J. M. +2 more
Context. Despite their relatively high intrinsic brightness and the fact that they are more numerous than younger OB stars and kinematically colder than older red giants, A-type stars have rarely been used as Galactic tracers. They may, in fact, be used to fill the age gap between these two tracers, thereby allowing us to evaluate the evolutionary…
Misalignment of the outer disk of DK Tau and a first look at its magnetic field using spectropolarimetry
Donati, J. -F.; Vidotto, A. A.; Bouvier, J. +7 more
Context. Misalignments between a forming star's rotation axis and its outer disk axis, although not predicted by standard theories of stellar formation, have been observed in several classical T Tauri stars (cTTs). The low-mass cTTs DK Tau is suspected of being among them. In addition, it is an excellent subject to investigate the interaction betw…
Magnetic helicity and free magnetic energy as tools for probing eruptions in two differently evolving solar active regions
Georgoulis, M. K.; Nindos, A.; Liokati, E.
Aims: We study the role of magnetic helicity and free magnetic energy in the initiation of eruptions in two differently evolving solar active regions (ARs).
Methods: Using vector magnetograms from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and a magnetic connectivity-based method, we calculate the instan…
Solar activity relations in energetic electron events measured by the MESSENGER mission
Lario, D.; Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F. +10 more
Aims: We perform a statistical study of the relations between the properties of solar energetic electron (SEE) events measured by the MESSENGER mission from 2010 to 2015 and the parameters of the respective parent solar activity phenomena in order to identify the potential correlations between them. During the time of analysis, the MESSENGER …
VLBI imaging of high-redshift galaxies and protoclusters at low radio frequencies with the International LOFAR Telescope
van Weeren, R. J.; Röttgering, H. J. A.; Miley, G. K. +4 more
It is generally known that luminous, ultra-steep spectrum radio sources are preferentially associated with massive galaxies at high redshifts. In this paper, we describe a pilot project directed at such objects to demonstrate the feasibility and importance of using the LOw-Frequency ARray (LOFAR) data to study the most distant massive galaxies und…
SPICE point spread function correction: General framework and capability demonstration
Peter, H.; Auchère, F.; Fludra, A. +4 more
We present a new method of removing point spread function (PSF) artifacts and improving the resolution of multidimensional data sources, including imagers and spectrographs. Rather than deconvolution, which is translationally invariant, the method we present is based on sparse matrix solvers. This allows it to be applied to spatially varying PSFs …
Identification of late-type Class I stars using Gaia DR3 Apsis parameters
Messineo, Maria
Aims: We examined the Gaia DR3 GSP-Phot and GSP-Spec parameters of known K- and M-type stars of Class I luminosity to make a comparison with the parameters collected from the literature to assess their accuracy and their potential in setting stellar classifications of intrinsically bright late-types that have been unknown thus far. Gaia DR3 G…
Study of oxygen-rich post-AGB stars in the Milky Way as a means to explain the production of silicates among evolved stars
Dell'Agli, F.; Ventura, P.; Marchetti, T. +4 more
Context. The study of post-asymptotic giant branch (post-AGB) stars is a valuable tool in improving our understanding of poorly known aspects of the evolution of the stars throughout the asymptotic giant branch (AGB). This can be done thanks to the availability of more accurate determinations of their surface chemical composition and the peculiar …
Similar levels of deuteration in the pre-stellar core L1544 and the protostellar core HH211
Caselli, P.; Spezzano, S.; Lique, F. +6 more
Context. In the centre of pre-stellar cores, deuterium fractionation is enhanced due to low temperatures and high densities. Therefore, the chemistry of deuterated molecules can be used to probe the evolution and the kinematics in the earliest stages of star formation.
Aims: We analyse the deuterium fractionation of simple molecules, comparin…
Properties of the dense cores and filamentary structures in the Vela C molecular cloud
Zhang, Guo-Yin; Zhang, Chang; Li, Jin-Zeng +3 more
The initial and boundary conditions of the Galactic star formation in molecular clouds are not well understood. In an effort to shed new light on this long-standing problem, we measured the properties of dense cores and filamentary structures in the Vela C molecular cloud, observed with Herschel. We used the hires algorithm to create high-resoluti…