HARROW: Astronomers discovered a nest of monstrous baby galaxies 11.5 billion light-years away using the Atacama Large Millimeter/submillimeter Array (ALMA). The young galaxies seem to reside at the junction of gigantic filaments in a web of dark matter. These findings are important for understanding how monstrous galaxies like these are formed and how they evolve in to huge elliptical galaxies.
We are living in a relatively quiet period in the history of the Universe. Ten billion years ago, long before the Sun and Earth were formed, areas of the Universe were inhabited by monstrous galaxies with star formation rates hundreds or thousands of times what we observe today in the Milky Way galaxy. There aren’t any monstrous galaxies left in the modern Universe, but astronomers believe that these young galaxies matured into giant elliptical galaxies which are seen in the modern Universe.
Current galaxy formation theories predict that these monstrous galaxies form in special environments where dark matter is concentrated. But up until now it has been difficult to determine the positions of active star forming galaxies with enough precision to actually test this prediction. Part of the problem is that monstrous star-forming galaxies are often obscured in dust, making them difficult to observe in visible light. Dusty galaxies do emit strong radio waves with submillimeter wavelengths, but radio telescopes typically have not had the resolution needed to pin-point individual galaxies.