A authoritative interrogation in astronomy is how much stuff is in the Universe ? Researchers have now put a newfangled point of accumulation on the reply .
astronomer measure this as a fraction of the critical concentration of the universe , a useful parameter that is used as a benchmark to line the geometry of the cosmos . Observations over time have shown that the full topic - energy density of the population is very , very skinny to this critical tightness . Now a new subject field publish inThe Astrophysical Journalsuggests that about 31.5 percent of that value is due to matter .
“ To put that amount of matter in setting , if all the matter in the population were spread out out evenly across blank space , it would correspond to an ordinary mass tightness equal to only about six H atoms per cubic meter , ” first author Mohamed Abdullah , a alum researcher in the UC Riverside , said in astatement . “ However , since we know 80 pct of matter is actually benighted affair , in reality , most of this topic consists not of hydrogen atoms but rather of a case of topic which cosmologists do n’t yet empathize . ”
judge how much affair is in the Universe is not an soft project , so the squad had to get creative . The turn of galaxy clump in the local universe depends on the full amount of matter . If there were more issue , there would be more cluster . The challenge then is to assess how monumental those bunch are and find a sum .
“ The ‘ Goldilocks ’ challenge for our team was to measure the figure of clusters and then square up which solvent was ‘ just correct . ’ But it is unmanageable to measure the mickle of any galaxy cluster accurately because most of the matter is dark so we ca n’t see it with telescopes , " enjoin Abdullah .
The team developed a cosmological tool calledGalWeight , which apply the motion of the galaxies in clusters to happen a total mass . Those value were then inputted into a cosmologic pretence from which the squad was able to take out a final idea .
“ We have succeeded in making one of the most precise measurements ever made using the galaxy bunch proficiency , ” explain co - author Gillian Wilson , a professor of physical science and astronomy at UCR in whose lab Abdullah works . “ Moreover , this is the first use of the extragalactic nebula eye socket proficiency which has obtained a economic value in agreement with those obtained by teams who used noncluster technique such as cosmic microwave background anisotropies , baryon acoustical oscillation , Type Ia supernovae , or gravitative lensing . ”
