The Cosmic Evolution Survey (COSMOS) is an astronomical survey designed to probe the formation and evolution of galaxies as a function of both cosmic time (redshift) and the local galaxy environment. The survey covers a 2 square degree equatorial field with imaging by most of the major space-based telescopes and a number of large ground based telescopes, with many ongoing surveys. Over 2 million galaxies are detected, spanning 75% of the age of the Universe. The COSMOS survey involves more than 100 scientists in a dozen countries.
Any questions? - Contact us using this form.
Stay up-to-date! - Like us on Facebook or follow us on Twitter.
A team of researchers, led by Behnam Darvish, have been able to examine the cosmic web in great detail thanks to the plethora of high-quality COSMOS data available. The team have used the accurate photometric redshifts available within COSMOS, out to large cosmic distances, to map the density field within COSMOS. That is, they have determined the location of clusters of galaxies, filaments of the cosmic web and "normal" density regions called "the field." The cosmic web is the large-scale, complex network of galaxies, dark matter and gas that pervades throughout the Universe. The team found that a galaxy's position within the cosmic web plays an important role in determining the evolutionary pathway taken by the galaxy. They found that the cosmic web has a different influence on the rate of star formation within central galaxies (existing inside regions of high gravitational potential) compared to satellite galaxies (existing on the outskirts of these clusters). These findings will pave the way for exciting future work with upcoming telescopes such as LSST, Euclid, and WFIRST. Full article
A new study on COSMOS shows that between 35% and 60% of SMGs (i.e., highly star-forming galaxies) between z = 0 and z = 5 (1 billion years after the Big Bang) indeed reside in over-dense environments. However, the study also shows that the occurrence of SMGs occupying over-dense regions is lower at z < 3 compared to z > 3. This might indicate that highly star-forming galaxies can only be formed in high density regions at early cosmic epochs, while at later times, modest over-densities allow SMGs to form. For more information, check out their paper: http://adsabs.harvard.edu/abs/2017A%26A...597A...4S Full article
COSMOS data across many different wavelengths, including X-ray, infrared and radio, has been used to set the record for the most distant galaxy cluster ever discovered. We may be seeing the cluster, named CL J1001+0220, just after it's formation and while it is in the process of a big 'baby-boom' of star formation. Full article
A composite image of the cluster CL J1001+0220 in X-ray, infrared and radio. Image credit - X-ray: NASA/CXC/Université Paris/T.Wang et al; Infrared: ESO/UltraVISTA; Radio: ESO/NAOJ/NRAO/ALMA