Related papers: The Formation of Hydrogen Deficient Stars through …
We use three-dimensional hydrodynamical simulations to study the rapid infall phase of the common envelope interaction of a red giant branch star of mass equal to 0.88 \msun and a companion star of mass ranging from 0.9 down to 0.1 \msun.…
Over forty years of research suggests that the common envelope phase, in which an evolved star engulfs its companion upon expansion, is the critical evolutionary stage forming short-period, compact-object binary systems, such as coalescing…
The evolution of low mass (M < 2.5 Msun) binaries through the common envelope phase has been studied for systems in which one member is on its first ascent of the red giant branch. Three-dimensional hydrodynamical simulations have been…
The hydrodynamic evolution of the common envelope phase of a low mass binary composed of a 1.05 Msun red giant and a 0.6 Msun companion has been followed for five orbits of the system using a high resolution method in three spatial…
Modeling the evolution of progenitors of gravitational-wave merger events in binary stars faces two major uncertainties: the common-envelope phase and supernova kicks. These two processes are critical for the final orbital configuration of…
The engulfment of substellar bodies (SBs, such as brown dwarfs and planets) by giant stars is a possible explanation for rapidly rotating giants, lithium-rich giants, and the presence of SBs in close orbits around subdwarfs and white…
We quantify an evolutionary channel for single sdB stars based on mergers of binaries containing a red giant star and a lower mass main sequence or brown dwarf companion in our Galaxy. Population synthesis calculations that follow mergers…
We describe high resolution Smoothed Particle Hydrodynamics (SPH) simulations of three approximately $M_*$ field galaxies starting from \LCDM initial conditions. The simulations are made intentionally simple, and include photoionization,…
Common-envelope phases are decisive for the evolution of many binary systems. Of particular interest are cases with asymptotic giant branch (AGB) primary stars, because they are thought to be progenitors of various astrophysical transients.…
Theory and simulations suggest that it is possible to form low-mass hydrogen-burning stars, brown dwarfs and planetary-mass objects via disc fragmentation. As disc fragmentation results in the formation of several bodies at comparable…
Li-depleted (enhanced) stars in the main-sequence (MS) and (or) the RGB, pose a puzzling mystery. Presently, there is still no clear answer to the mechanism(s) that enables such Li depletion (enhancement). One possible explanation comes…
Hot subdwarf stars of spectral type B (sdBs) are evolved, core helium-burning objects. The formation of those objects is puzzling, because the progenitor star has to lose almost its entire hydrogen envelope in the red-giant phase. Binary…
White dwarfs are often found in close binaries with stellar or even substellar companions. It is generally thought that these compact binaries form via common envelope evolution, triggered by the progenitor of the white dwarf expanding…
We present preliminary results on galactic Dark Matter (DM), halo structure, and galaxy evolution. We show how during the first Gyr of the evolution of a $10^{10} M_{\odot}$ dwarf elliptica feed-back from stars (SN\ae~ and stellar winds)…
We use high resolution Hydro$+$N-Body cosmological simulations to compare the assembly and evolution of a small field dwarf (stellar mass ~ 10$^{6-7}$ M$\odot$, total mass 10$^{10}$ M$\odot$ in $\Lambda$ dominated CDM and 2keV WDM…
We present a large sample of fully self-consistent hydrodynamical Nbody/Tree-SPH simulations of isolated dwarf spheroidal galaxies (dSphs). It has enabled us to identify the key physical parameters and mechanisms at the origin of the…
The formation of a double white dwarf binary likely involves a common envelope (CE) event between a red giant and a white dwarf (WD) during the most recent episode of Roche lobe overflow mass transfer. We study the role of recombination…
A binary neutron star merger has been observed in a multi-messenger detection of gravitational wave (GW) and electromagnetic (EM) radiation. Binary neutron stars that merge within a Hubble time, as well as many other compact binaries, are…
We present the results of a set of high-resolution simulations of the merging process of two white dwarfs. In order to do so, we use an up-to-date Smoothed Particle Hydrodynamics code which incorporates very detailed input physics and an…
We study a sample of nearby (z~0.2) low-luminosity dwarf (10^7 MSun < M* < 10^8 MSun) galaxies which have extreme (0.1 - 3 MSun/yr) star formation rates (SFRs) for this mass regime, making them plausible analogues of dwarfs at z~5.5. We…