Speaker
Description
According to the prescriptions of the conventional cosmological LCDM-model, first galaxies had to start their formation when hierarchically assembled dark halos reached 100 million solar masses. They are thought to be dwarf disk galaxies. In fact, the earliest galaxy is observed now at the redshift of z=11, about 0.5 Gyr after the Big Bang, and it is much more massive than a hypothetical first-generation galaxy in the theory. Perhaps, it is related to the method of searching for high-redshift galaxies due to a so called ‘astronomical selection’ effect. However, all we know now about the galaxies having lived during the first billion year of the Universe evolution can be attributed mostly to ‘Ly-break’ galaxies – those with the typical stellar mass of 10 billion solar masses, with the star formation rate of a few dozen solar mass per year, and nearly solar chemical composition. All the hopes to find more early galaxies at z>12 are now related to the James Webb Space Telescope which surveys the sky with an unprecedent high spatial resolution in the mid-infrared spectral range where the peak of galaxy luminosity is expected for objects at z>12.
