Superclusters are the largest over-dense, relatively isolated systems in the cosmic web. They provide us invaluable information about the large-scale structure formation at different cosmic epochs, as well as they are excellent places for understanding galaxy evolution in detail. Thanks to the new SDSS-III data, we can extend our knowledge of superclusters to the redshift range above z=0.4. We used data from the twelfth data release of the Sloan Digital Sky Survey (SDSS). Using a sample of more than 500,000 galaxies up to z~0.8, we reconstructed the large-scale luminosity-density field and we used it to detect large-scale over-dense regions. The largest structure in this field, that we called the BOSS Great Wall (BGW), is located at z~0.47 and consisted of two walls with diameters ~180 h-1 Mpc each. The BGW is the larger in volume and diameter structure than any previously known superclusters. Other known superclusters, like the Sloan Great Wall or Laniakea are almost half the size of the BGW. In addition, the BGW contains 830 galaxies and the total mass of our system is at least two times higher than any other superclusters. These characteristics make the BOSS Great Wall the richest, and largest system found in the Universe, and one of the most massive structures ever known.
Advertised on
References
It may interest you
-
The standard cosmological model states that massive galaxies contain a large fraction of dark matter. Dark matter is a transparent substance that does not interact through regular baryonic matter and is only detected through its gravitational pull over the stars and the gas. NGC 1277 is known as the prototype of a relic galaxy, that is, a galaxy that has not accreted other galaxies since it formed. Relic galaxies are extremely rare and are the untouched remains of the giant galaxies that populated the early Universe. Since relic galaxies are very important to understand the conditions in theAdvertised on
-
The amount and complexity of data delivered by modern galaxy surveys has been steadily increasing over the past years. New facilities will soon provide imaging and spectra of hundreds of millions of galaxies. Extracting coherent scientific information from these large and multi-modal data sets remains an open issue for the community and data-driven approaches such as deep learning have rapidly emerged as a potentially powerful solution to some long lasting challenges. This enthusiasm is reflected in an unprecedented exponential growth of publications using neural networks, which have goneAdvertised on
-
H II regions are ionized nebulae associated with the formation of massive stars. They exhibit a wealth of emission lines in their spectra that form the basis for estimation of chemical composition. The amount of heavy chemical elements is essential to the understanding of important phenomena such as nucleosynthesis, star formation and chemical evolution of galaxies. For over 80 years, however, a discrepancy exists of a factor of around two between heavy-element abundances (the so-called metallicity) derived from the two main kinds of emission lines that can be measured in nebular spectraAdvertised on