Filtyp
We investigate the evolution of the abundance of fluorine in the Milky Way thick and thin discs by means of detailed chemical evolution models compared with recent observational data. The chemical evolution models adopted here have already been shown to fit the observed abundance patterns of CNO and α-elements as well as the metallicity distribution functions for the Galactic thick and thin disc s
The Gaia-ESO Survey (GES) observed many open clusters as part of its programme to spectroscopically characterize the various Milky Way populations. GES spectroscopy and Gaia astrometry from its second data release are used here to assign membership probabilities to targets towards 32 open clusters with ages from 1 to 3800 Myr, based on maximum likelihood modelling of the 3D kinematics of the clust
We report that the density profiles of globular cluster (GC) systems in a sample of 17 early-Type galaxies (ETGs) show breaks at the radii where the gravitational acceleration exerted by the stars equals the galactic acceleration scale a0 known from the radial acceleration relation or the modified Newtonian dynamics (MOND). The match with the other characteristic radii in the galaxy is not that cl
We study the chemical evolution of Zr, La, Ce, and Eu in the Milky Way discs and bulge by means of chemical evolution models compared with spectroscopic data. We consider detailed chemical evolution models for the Galactic thick disc, thin disc, and bulge, which have been already tested to reproduce the observed [α/Fe] versus [Fe/H] diagrams and metallicity distribution functions for the three dif
Sizeable number of stellar-mass black holes (BHs) in globular clusters (GCs) can strongly influence the dynamical evolution and observational properties of their host cluster. Using results from a large set of numerical simulations, we identify the key ingredients needed to sustain a sizeable population of BHs in GCs up to a Hubble time. We find that while BH natal kick prescriptions are essential
We investigate the dissolution process of star clusters embedded in an external tidal field and harboring a subsystem of stellar-mass black hole. For this purpose we analyzed the MOCCA models of real star clusters contained in the Mocca Survey Database I. We showed that the presence of a stellar-mass black hole subsystem in tidally filling star cluster can lead to abrupt cluster dissolution connec
Meteor radar observations carried out in August-September 1953-84 at theOnsala Space Observatory in Sweden show long-term, as well as short termvariations in meteor radar rates. These rate variations are associatedwith position in the solar cycle, and with variations in the solar windsector structure. An inverse correlation is found between meteor radarrates and the solar cycle. The magnitude of t
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This thesis shows how artificial neural networks (ANNs) can be applied to predict geomagnetic activity from solar-wind data. It introduces and summarizes five papers where development of ANN models are reported, and where predictions of geomagnetic activity are discussed. The studies cover geomagnetic disturbances characterized by global-scale indices and geomagnetic variations that are locally ob
The purpose of the IAU Meteor Data Center is to archive, document anddisseminate information on meteoroid orbits. At present 4581 preciselyreduced photographic recordings, 1425 video recordings and 63330 radardetermined orbits are archived at the center.
