GN-z11 is a high-redshift

galaxy A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System ...

found in the constellation

Ursa Major Ursa Major (; also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear," referring to and contrasting it with nearby Ursa ...

. It is one of the farthest known galaxies from Earth ever discovered. The 2015 discovery was published in a 2016 paper headed by Pascal Oesch and Gabriel Brammer (Cosmic Dawn Center). Up until the discovery of HD1 in 2022, GN-z11 was the oldest and most distant known galaxy yet identified in the

observable universe The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these ob ...

, having a spectroscopic

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 simultaneous increase in fr ...

of , which corresponds to a

proper distance Proper length or rest length is the length of an object in the object's rest frame. The measurement of lengths is more complicated in the theory of relativity than in classical mechanics. In classical mechanics, lengths are measured based on t ...

of approximately .At first glance, the distance of might seem impossibly far away in a Universe that is only 13.8 billion (short scale) years old, where a light-year is the distance light travels in a year, and where nothing can travel faster than the speed of light. However, because of the

expansion of the universe The expansion of the universe is the increase in distance between any two given gravitationally unbound parts of the observable universe with time. It is an intrinsic expansion whereby the scale of space itself changes. The universe does not ex ...

, the distance of 2.66 billion light-years between GN-z11 and the Milky Way at the time when the light was emitted increased by a factor of (z+1)=12.1 to a distance of 32.2 billion light-years during the 13.4 billion years it has taken the light to reach us. See:

Size of the observable universe The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these o ...

, Misconceptions about the size of the observable universe, Measuring distances in expanding space, and Ant on a rubber rope. The object's name is derived from its location in the GOODS-North field of galaxies and its high cosmological redshift number . It is observed as it existed 13.4 billion years ago, just 400 million years after the

Big Bang The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

; as a result, its distance is sometimes inappropriately reported as 13.4 billion light-years, its light-travel distance measurement. The galaxy has such a high redshift that its

angular diameter distance In astronomy, angular diameter distance is a distance defined in terms of an object's physical size, x, and its angular size, \theta, as viewed from Earth: d_A= \frac Cosmology dependence The angular diameter distance depends on the assumed cos ...

is actually less than that of some galaxies with lower redshift. This means that the ratio of its angular size to its size in light-years is greater.

Discovery

The galaxy was identified by a team studying data from the

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

's Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, ...

Great Observatories Origins Deep Survey The Great Observatories Origins Deep Survey, or GOODS, is an astronomical survey combining deep observations from three of NASA's Great Observatories: the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory, al ...

-North (GOODS-North). The research team used Hubble's Wide Field Camera 3 to measure the distance to GN-z11 spectroscopically, measuring the

caused by the

. The findings, which were announced in March 2016, revealed the galaxy to be farther away than originally thought, at the distance limit of what the Hubble Telescope can observe. GN-z11 is around 150 million years older than the previous record-holder

EGSY8p7 __NOTOC__ EGSY8p7 (EGSY-2008532660) is a distant galaxy in the constellation of Boötes, with a spectroscopic redshift of ''z'' = 8.68 (photometric redshift 8.57), a light travel distance of 13.2 billion light-years from Earth. Therefore ...

, and is observed (shortly after but) "very close to the end of the so-called Dark Ages of the universe", and (during but) "near the very beginning" of the reionization era. Compared with the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. ...

galaxy, GN-z11 is of the size, has 1% of the mass, and is forming new stars approximately twenty times as fast. With a stellar age estimated at 40 million years, it appears the galaxy formed its stars relatively rapidly. The fact that a galaxy so massive existed so soon after the first stars started to form is a challenge to some current theoretical models of the formation of galaxies.

Notes

References

{{2016 in space 20160303 Ursa Major (constellation) Dwarf irregular galaxies

Discovery

See also

Notes

References