Cosmos Redshift 7 (also known as COSMOS Redshift 7, Galaxy Cosmos Redshift 7, Galaxy CR7 or CR7) is a high-redshift Lyman-alpha emitter

galaxy A galaxy is a Physical system, system of stars, stellar remnants, interstellar medium, interstellar gas, cosmic dust, dust, and dark matter bound together by gravity. The word is derived from the Ancient Greek, Greek ' (), literally 'milky', ...

. At a

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and increase in frequency and e ...

z = 6.6, the galaxy is observed as it was about 800 million years after the

Big Bang The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including th ...

, during the epoch of reionisation. With a light travel time of 12.9 billion years, it is one of the oldest, most distant galaxies known. CR7 shows some of the expected signatures of

Population III stars In 1944, Walter Baade categorized groups of stars within the Milky Way into stellar populations. In the abstract of the article by Baade, he recognizes that Jan Oort originally conceived this type of classification in 1926. Baade observed tha ...

i.e. the first generation of stars produced during early galaxy formation. These signatures were detected in a bright pocket of blue stars; the rest of the galaxy contains redder Population II stars. However, recent studies show no evidence for population III stars in CR7.

Description

Galaxy Cosmos Redshift 7 contains old Population II (metal-poor) and possibly Population III (stars with extremely poor

metallicity In astronomy, metallicity is the Abundance of the chemical elements, abundance of Chemical element, elements present in an object that are heavier than hydrogen and helium. Most of the normal currently detectable (i.e. non-Dark matter, dark) matt ...

), according to astronomers, and is three times brighter than the brightest distant galaxies ( redshift, z > 6) detected up to the time of its discovery.

Discovery

Astronomers led by David Sobral, a Reader in Astrophysics at the

University of Lancaster Lancaster University (officially The University of Lancaster) is a collegiate public university, public research university in Lancaster, Lancashire, England. The university was established in 1964 by royal charter, as one of several new univer ...

, used the

Very Large Telescope The Very Large Telescope (VLT) is an astronomical facility operated since 1998 by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile. It consists of four individual telescopes, each equipped with ...

(VLT) at the

European Southern Observatory The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental organization, intergovernmental research organisation made up of 16 m ...

—with help from the W. M. Keck Observatory, Subaru Telescope and the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

/ ESA

Hubble Space Telescope The Hubble Space Telescope (HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the Orbiting Solar Observatory, first space telescope, but it is one of the largest and most ...

—made the discovery. The research team included members of the

University of California, Riverside The University of California, Riverside (UCR or UC Riverside) is a public university, public Land-grant university, land-grant research university in Riverside, California, United States. It is one of the ten campuses of the University of Cali ...

University of Geneva The University of Geneva (French: ''Université de Genève'') is a public university, public research university located in Geneva, Switzerland. It was founded in 1559 by French theologian John Calvin as a Theology, theological seminary. It rema ...

University of Leiden Leiden University (abbreviated as ''LEI''; ) is a public research university in Leiden, Netherlands. Established in 1575 by William, Prince of Orange as a Protestant institution, it holds the distinction of being the oldest university in the Neth ...

and

University of Lisbon The University of Lisbon (ULisboa; ) is a public university, public research university in Lisbon, and Portugal's largest university. It was founded in 1911, but the university's present structure dates to the 2013 merger of the former Universit ...

. The name of the galaxy (''Cosmos Redshift 7 Galaxy)'' was inspired by football player

Cristiano Ronaldo Cristiano Ronaldo dos Santos Aveiro (; born 5 February 1985) is a Portuguese professional Association football, footballer who plays as a Forward (association football), forward for and Captain (association football), captains both Saudi Pr ...

, also popularly known as CR7.

References

External links

*
Cosmos Redshift 7 galaxy
on Deep Space Map {{DEFAULTSORT:Cosmos Redshift 7 ? Cristiano Ronaldo Galaxies

Description

Discovery

See also

References

External links