Related papers: Explosive Chrysopoeia
It is known that the gravitational collapse of a dust ball results in naked singularity formation from an initial density profile which is physically reasonable. In this paper, we show that explosive radiation is emitted during the…
I develop a high velocity galaxy collision model to explain a rare but puzzling phenomenon, namely the apparent existence of ultra-diffuse galaxies with little dark matter. Predictions include simultaneous triggering of overpressured dense…
In the last decades, luminous accreting super-massive black holes have been discovered within the first Gyr after the Big Bang, but their origin is still an unsolved mystery. We discuss our state-of-the-art theoretical knowledge of their…
Superbursts were discovered at the beginning of this millennium. Just like type-I X-ray bursts, they are thought to be due to thermonuclear shell flashes on neutron stars, only igniting much deeper. With respect to type-I bursts, they last…
Black holes are the densest form of energy, and in the presence of compact dimensions black objects may take one of several forms including the black-hole and the black-string, the simplest relevant background being R^{3+1} * S^1. Recent…
By means of analytical calculations, we explore the self-enrichment scenario for Globular Cluster formation. According to this scenario, an initial burst of star formation occurs inside the core radius of the initial gaseous distribution.…
For a few seconds a gamma-ray burst (GRB) becomes the brightest object in the Universe, over-shining the rest of the Universe combined! Clearly this reflects extreme conditions that are fascinating and worth exploring. The recent discovery…
We explore a scenario where metal-poor globular clusters (GCs) are enriched by the first supernovae in the Universe. If the first stars in a 10^7 Msun dark halo were very massive (>180 Msun), then a pair instability supernova from a single…
The chemical elements are created in nuclear fusion processes in the hot and dense cores of stars. The energy generated through nucleosynthesis allows stars to shine for billions of years. When these stars explode as massive supernovae, the…
We show that the "puzzling" chemical composition observed in the extremely metal poor star HE0107-5240 may be naturally explained by the concurrent pollution of at least two supernovae. In the simplest possible model a supernova of quite…
Metal-poor stars hold the key to our understanding of the origin of the elements and the chemical evolution of the Universe. This chapter describes the process of discovery of these rare stars, the manner in which their surface abundances…
The external pollution of the first stars in the Galaxy is investigated. The first stars were born in clouds composed of the pristine gas without heavy elements. These stars accreted gas polluted with heavy elements while they still…
Metallic nanostructures can support so-called plasma oscillations (plasmons). Plasmons allow for the concentration of the energy from light, down to sizes well below the conventional diffraction limit known from optics. Plasmonics thus…
Ancient objects made of noble metal alloys, that is, gold with copper and/or silver, can show the phenomenon of surface enrichment. This phenomenon is regarding the composition of the surface, which has a percentage of gold higher than that…
A lot of beautiful observations of Supernova remnant 1987A give a precise idea of its structure and its evolution. The regular interpretations of the observations set that the large energy needed to explain the brightness of the pearl…
Since the early seventies, there was a conjecture that the first collapse of a selfgravitating dust--like medium (appropriate approximation for nonbaryonic dark matter) results in the formation of a ``pancake" object, that is a thin…
We investigate the supernova explosions that end the lives of massive Population III stars in low-mass minihalos (M~10^6 M_sun) at redshifts z~20. Employing the smoothed particle hydrodynamics method, we carry out numerical simulations in a…
We made a detailed study of Saint Elmo's Fire in the laboratory and discovered that the fire is due to sparking along the jets emitted from conically shaped water droplets located on objects.
The explosive crystallization of germanium ultradisperse amorphous films is studied experimentally. We show that crystallization may be initiated by local heating at the small film thickness but it realizes spontaneously at the large ones.…
We present the discovery of the Type II supernova SN 2023ixf in M101 and follow-up photometric and spectroscopic observations, respectively, in the first month and week of its evolution. Our discovery was made within a day of estimated…