Infrared astronomy is a sub-discipline of astronomy which specializes in the observation and analysis of astronomical objects using infrared (IR) radiation. The wavelength of infrared light ranges from 0.75 to 300 micrometers, and falls in between visible radiation, which ranges from 380 to 750 nanometers, and submillimeter waves.
The following is a timeline of galaxies, clusters of galaxies, and large-scale structure of the universe.
The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area about 2.6 arcminutes on a side, about one 24-millionth of the whole sky, which is equivalent in angular size to a tennis ball at a distance of 100 metres. The image was assembled from 342 separate exposures taken with the Space Telescope's Wide Field and Planetary Camera 2 over ten consecutive days between December 18 and 28, 1995.
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; the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. Initially, it was estimated that there may be 2 trillion galaxies in the observable universe, although that number was reduced in 2021 to only several hundred billion based on data from New Horizons. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical region centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth.
Abell 1835 IR1916 was a candidate for being the most distant galaxy ever observed, although that claim has not been verified by additional observations. It was claimed to lie behind the galaxy cluster Abell 1835, in the Virgo constellation.
XMMXCS 2215-1738 is a galaxy cluster that lies 10 billion light-years away and has a redshift value of z=1.45. It was discovered by the XMM Cluster Survey in 2006.
A1689-zD1 is a galaxy in the Virgo constellation. It was a candidate for the most distant and therefore earliest-observed galaxy discovered as of February 2008, based on a photometric redshift.
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, along with data from other space-based telescopes, such as XMM Newton, and some of the world's most powerful ground-based telescopes.
GRB 090423 was a gamma-ray burst (GRB) detected by the Swift Gamma-Ray Burst Mission on April 23, 2009 at 07:55:19 UTC whose afterglow was detected in the infrared and enabled astronomers to determine that its redshift is z = 8.2, which makes it one of the most distant objects detected to date with a spectroscopic redshift.
UDFy-38135539 is the Hubble Ultra Deep Field (UDF) identifier for a galaxy which was calculated as of October 2010 to have a light travel time of 13.1 billion years with a present proper distance of around 30 billion light-years.
SXDF-NB1006-2 is a distant galaxy located in the Cetus constellation, with a spectroscopic redshift of z = 7.213 or 12.91 billion light-years away. It was discovered by the Subaru XMM-Newton Deep Survey Field. The galaxy was claimed to be the most distant galaxy at announcement in June 2012, as the more distant claimants were not confirmed spectroscopically at the time. It exceeded the previous confirmed distance holder, GN-108036, also discovered by the Subaru. Oxygen emission lines have been detected in its spectrum.
The XDCPJ0044.0-2033 (Gioello) galaxy cluster at redshift z=1.579 was discovered in the archive of the XMM-Newton mission, as part of the XMM-Newton Distant Cluster Project (XDCP) and first published by Santos et al. 2011. Gioiello is the most distant massive galaxy cluster that has been found and studied today. This massive galaxy cluster contains 400 trillion times the mass of the Sun and is located 9.6 billion light years away from Earth. The name Gioiello, meaning "jewel" in Italian, was given to this massive galaxy cluster because an image of the cluster contains many beautiful pink, purple, and red sparkling colors from the hot X-ray–emitting gas and other star-forming galaxies within the cluster.
EGS-zs8-1 is a high-redshift Lyman-break galaxy found at the northern constellation of Boötes. In May 2015, EGS-zs8-1 had the highest spectroscopic redshift of any known galaxy, meaning EGS-zs8-1 was the most distant and the oldest galaxy observed. In July 2015, EGS-zs8-1 was surpassed by EGSY8p7 (EGSY-2008532660).
Cosmos Redshift 7 is a high-redshift Lyman-alpha emitter galaxy. At a redshift z = 6.6, the galaxy is observed as it was about 800 million years after the Big Bang, 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.
EGSY8p7 (EGSY-2008532660) is a distant galaxy in the constellation of Boötes, with a spectroscopic redshift of z = 8.68, a light travel distance of 13.2 billion light-years from Earth. Therefore, at an age of 13.2 billion years, it is observed as it existed 570 million years after the Big Bang, which occurred 13.8 billion years ago, using the W. M. Keck Observatory. In July 2015, EGSY8p7 was announced as the oldest and most-distant known object, surpassing the previous record holder, EGS-zs8-1, which was determined in May 2015 as the oldest and most distant object. In March 2016, Pascal Oesch, one of the discoverers of EGSY8p7, announced the discovery of GN-z11, an older and more distant galaxy.
GN-z11 is a high-redshift galaxy found in the constellation Ursa Major. It is among the farthest known galaxies from Earth ever discovered. The 2015 discovery was published in a 2016 paper headed by Pascal Oesch and Gabriel Brammer. Up until the discovery of JADES-GS-z13-0 in 2022 by the James Webb Space Telescope, GN-z11 was the oldest and most distant known galaxy yet identified in the observable universe, having a spectroscopic redshift of z = 10.957, which corresponds to a proper distance of approximately 32 billion light-years.
MACS 1423-z7p64 is a galaxy listed in the MAssive Cluster Survey (MACS), and announced on 10 April 2017 in the journal Nature Astronomy, as being the most distant source of reionization known at this time, with a redshift z = 7.640 ± 0.001.
ULAS J1342+0928 is the second-most distant known quasar detected and contains the second-most distant and oldest known supermassive black hole, at a reported redshift of z = 7.54. The ULAS J1342+0928 quasar is located in the Boötes constellation. The related supermassive black hole is reported to be "800 million times the mass of the Sun".
The Hyperion proto-supercluster is the largest and earliest known proto-supercluster, 5,000 times the mass of the Milky Way and seen at 20% of the current age of the universe. It was discovered in 2018 by analysing the redshifts of 10,000 objects observed with the Very Large Telescope in Chile.
HD1 is a proposed high-redshift galaxy, which is considered to be one of the earliest and most distant known galaxies yet identified in the observable universe. The galaxy, with an estimated redshift of approximately z = 13.27, is seen as it was about 324 million years after the Big Bang, which was 13.787 billion years ago. It has a light-travel distance of 13.463 billion light-years from Earth, and, due to the expansion of the universe, a present proper distance of 33.288 billion light-years.
