Figure 26-21: R I V U X G
“Bottom-Up” Galaxy Formation: Observation (a) The hexagons in this image from the Very Large Telescope show the positions of a number of sub-galaxy-sized objects at a redshift z = 3.04, the same as in the simulation shown in Figure 26-20. Excited hydrogen atoms in these objects emit ultraviolet photons, which are redshifted to visible wavelengths. This redshifted emission gives these objects a characteristic green color. (The object at lower left actually lies in front of a much brighter quasar.) (b) The objects in (a) all lie within an immense filament. The purple box shows the volume of space studied in this observing program. The dimensions are given in millions of light-years (Mly).
“Bottom-Up” Galaxy Formation: Observation (a) The hexagons in this image from the Very Large Telescope show the positions of a number of sub-galaxy-sized objects at a redshift z = 3.04, the same as in the simulation shown in Figure 26-20. Excited hydrogen atoms in these objects emit ultraviolet photons, which are redshifted to visible wavelengths. This redshifted emission gives these objects a characteristic green color. (The object at lower left actually lies in front of a much brighter quasar.) (b) The objects in (a) all lie within an immense filament. The purple box shows the volume of space studied in this observing program. The dimensions are given in millions of light-years (Mly).
(European Southern Observatory)