|
The panel at left shows the current distribution of dark matter in our own Milky Way galaxy.
Bright clumps correspond to high concentrations of dark matter and the black boxes highlight dark matter dominated dwarf satellites whose origin constitutes the main target of Kazantzidis' study. The frame measures 260 kiloparsecs on a side, roughly ten times the diameter of the visible part of the Milky Way galaxy.
The multiple panels on the right show the morphological evolution of the luminous matter of one of these dwarf satellites that fell into the Milky Way about 10 billion years ago.
Brighter colors indicate regions of higher density. The time corresponding to each snapshot is given by the labels.
The first frame shows the original disk of stars contained in the progenitors of these dwarf spheroidal galaxies according to Kazantzidis' model.
The two middle panels show the stars and gas after 3 billion years of evolution, which corresponds to a time at which the satellite galaxy
approached the Milky Way for the second time. Tidal shocking strips
the stars, which can be seen as faint structures in the outskirts of the disk,
from the galaxy.
On the other hand, ram pressure in synergy with the cosmic ultraviolet background removes the gaseous component, producing a pronounced trail of stripped gas. The bottom panel shows the end state of the stars and demonstrates a unique transformation: the original dense stellar disk has been transformed into a diffuse spheroidal component.
The most dark dominated structure known in the universe has been born.
All images are from supercomputer
simulations and are courtesy of Kazantzidis.
Click on image
for high-res version.
|
