5 research outputs found
Dust-free starburst galaxies at redshifts
One of the most distant galaxies GN-z11 was formed when the Universe was
400 Myr old, and it displays a burst-like star formation rate \sim
25~\msun yr with a metallicity . It resembles
galaxies (at ``cosmic noon") except for the fact that the measured
reddening indicates the presence of little or no dust.
This marked absence of dust hints towards violent dynamical events that destroy
or evacuate dust along with gas out of the galaxy on a relatively short time
scale and make it transparent. We apply a 3D numerical model to infer possible
physical characteristics of these events. We demonstrate that the energetics of
the observed star formation rate is sufficient to tear apart the dusty veil on
time scales of Myr. This can explain the apparent lack of evolution of
UV luminosity function of galaxies between and and , by
compensating for the lower galaxy masses at higher redshift by the absence of
dust. We show, however, that this is a temporary phenomenon and soon after the
last of the supernovae explosions have taken place, the expanding shell shrinks
and obscures the galaxy on time scales of Myr.Comment: submitted to MNRAS Letters, 5 pages, 4 figure
Features of the structure of metal composite alloy obtained by electric slag remelting with controlled magneto-hydrodynamic action
The results of experimental studies on the use of mineral raw materials containing zirconium oxides without its deep technological processing to create alloys by electroslag remelting are presented. Dependences of the transition of zirconium into remelted low-carbon steel on the magnitude of electromagnetic pulses have been established. It has been experimentally proven that zircon concentrate can be used as an alloying component to obtain alloyed alloys and coatings in electroslag technologies. In this case, the concentrate is used in a comprehensive manner, without additional technological processing
Features of the structure of metal composite alloy obtained by electric slag remelting with controlled magneto-hydrodynamic action
The results of experimental studies on the use of mineral raw materials containing zirconium oxides without its deep technological processing to create alloys by electroslag remelting are presented. Dependences of the transition of zirconium into remelted low-carbon steel on the magnitude of electromagnetic pulses have been established. It has been experimentally proven that zircon concentrate can be used as an alloying component to obtain alloyed alloys and coatings in electroslag technologies. In this case, the concentrate is used in a comprehensive manner, without additional technological processing
Production of functional materials on the basis of tungsten multicomponent mineral resources
We produced tungsten and tungsten carbide as a result of the synthesis of multicomponent tungsten mineral resource with the employment of high density energy flow. The results of experiments concerned with the possibility of using high-density energy to synthesize functional materials for industrial use are presented as well
Production of functional materials on the basis of tungsten multicomponent mineral resources
We produced tungsten and tungsten carbide as a result of the synthesis of multicomponent tungsten mineral resource with the employment of high density energy flow. The results of experiments concerned with the possibility of using high-density energy to synthesize functional materials for industrial use are presented as well