Abstract
One of the most distant galaxies GN-z11 was formed when the Universe was
$łe$ 400 Myr old, and it displays a burst-like star formation rate $\sim
25~\msun$ yr$^-1$ with a metallicity $Z0.20.1Z_ødot$. It resembles
$z=2-3$ galaxies (at ``cosmic noon") except for the fact that the measured
reddening $E(B-V)=0.010.01$ 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 $20-25$ Myr. This can explain the apparent lack of evolution of
UV luminosity function of galaxies between and $z10$ and $z7$, 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 $5-8$ Myr.
Users
Please
log in to take part in the discussion (add own reviews or comments).