Our current understanding of the Universe suggests that its largest structures, such as clusters and groups of galaxies, would have formed only within the second half of the Universe’s current age. However, today’s paper explores the proposed observational evidence that such structures may actually have began forming a lot earlier than we expected. This poses intriguing questions about the way we model the cosmos, how we interpret our observations, and whether we might need to rethink cosmology.
This is less a physical question than a moral one. Should we feed a black hole? If we do, will it ever learn to feed and fend for itself independently? Will it ever truly be able to return to the wild, or will it ever after be chained to the yoke of domestic comfort?
More than 50 years ago, a Norwegian astronomer named Sjur Refsdal outlined an interesting new method for calculating the Hubble constant. Last November, astronomers found the perfect test case.
Stars formed in the early Universe were extremely massive and extremely low in elements heavier than helium. The transition from the first to the second generation of stars is still hidden in the shadows of the past. However, simulations of the most massive supernovae can help us to decipher the way of how the life cycle of stars came into being.
Cepheids are bright enough that we can use them to measure distances to other galaxies, but their luminosities also makes detecting their companions particularly difficult. So how do astronomers find their uncover their secret partners? Today’s paper takes a look…
How can we measure the temperature of the Universe across cosmic epochs? Recent data from Planck suggests that the Universe’s cooling history is consistent with the Big Bang model.