GN-z11

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GN-z11
GN-z11 superimposed on an image from the GOODS-North survey
Observation data (J2000[1] epoch)
ConstellationUrsa Major[1]
Right ascension12h 36m 25.46s[1]
Declination+62° 14′ 31.4″[1]
Redshift11.09[2]
Distance~3.2×1010 ly
Characteristics
TypeGalaxy
Mass~1×109 M☉
Size4000 ±2000 ly (1.2 ±0.6 kpc)[2]

GN-z11 is a high-redshift galaxy found at the constellation Ursa Major, and is currently the oldest and most distant known galaxy in the Observable Universe.[3] GN-z11 has a spectroscopic redshift of z = 11.1, which corresponds to a comoving distance of approximately 32 billion light-years from Earth.[4][n 1]

The object's name is derived from its location in the GOODS-North field of galaxies and its high Doppler z-scale redshift number (GN + z11).[5] GN-z11 is observed as it existed 13.4 billion years ago, just 400 million years after the Big Bang;[6][2] as a result, GN-z11's distance is widely (and mistakenly)[7] reported as 13.4 billion light years.[8][9]

Discovery

The galaxy was identified by a team studying data from the Hubble Space Telescope's Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) and Spitzer Space Telescope's Great Observatories Origins Deep Survey-North (GOODS-North).[10][11] The research team used Hubble's Wide Field Camera 3 to measure the distance to GN-z11 spectroscopically, by splitting the light into its component colors to measure the redshift caused by the expansion of the universe.[12] The findings, which were announced in March 2016, revealed the galaxy to be farther away than originally thought, at the distance limit of what Hubble can observe. GN-z11 is around 150 million years older than the previous record-holder EGSY8p7,[5] and is observed (shortly after but) "very close to the end of the so-called Dark Ages of the universe",[12] and (during but) "near the very beginning" of the reionization era.[13]

Compared with the Milky Way galaxy, GN-z11 is twenty-five times smaller, has 1% of the mass, and is forming new stars approximately twenty times faster.[12] With a stellar age estimated at 40 million years, it appears the galaxy formed its stars relatively rapidly.[2] The fact that a galaxy so massive existed so soon after the first stars started to form is a challenge for some current theoretical models of the formation of galaxies.[12][14]

Notes

  1. ^ At first glance, the distance of 32 billion light years might seem impossibly far away in a Universe that is only 13.8 billion 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 distance of 13.4 billion light years traveled by light from GN-z11 to Earth, called the light-travel distance, has expanded to a distance of 32 billion light years during the 13.4 billion years it took the light to reach us.

    See:

References

  1. ^ a b c d "Hubble Team Breaks Cosmic Distance Record - Fast Facts". HubbleSite. March 3, 2016. STScI-2016-07. Retrieved March 4, 2016.
  2. ^ a b c d Oesch, P. A.; Brammer, G.; van Dokkum, P.; et al. (March 1, 2016). "A Remarkably Luminous Galaxy at z=11.1 Measured with Hubble Space Telescope Grism Spectroscopy" (PDF). arXiv:1603.00461. {{cite journal}}: Cite journal requires |journal= (help)
  3. ^ Klotz, Irene (March 3, 2016). "Hubble Spies Most Distant, Oldest Galaxy Ever". Discovery News. Retrieved March 3, 2016.
  4. ^ "Astronomers Spot Most Distant Galaxy—At Least For Now". Phenomena. Retrieved March 4, 2016. Yep, it took 13.4 billion years for light from the galaxy to zoom through the universe and collide with the Hubble Space Telescope. But that doesn't mean the galaxy is 13.4 billion light-years away. The universe has been expanding in the meantime, meaning GN-z11 is actually much, much farther from Earth than that.

    'Right now, we expect this galaxy to be about 32 billion light-years away from us in distance,' says study coauthor Pascal Oesch of Yale University.

  5. ^ a b "Hubble Team Breaks Cosmic Distance Record". NASA TV. March 3, 2016. Retrieved March 10, 2016.
  6. ^ Amos, Jonathan (March 3, 2016). "Hubble sets new cosmic distance record". BBC News. Retrieved March 3, 2016.
  7. ^ Wright, Edward L. (August 2, 2013). "Why the Light Travel Time Distance should not be used in Press Releases". UCLA. Retrieved March 10, 2016.
  8. ^ "Astronomers Spot Record Distant Galaxy From Early Cosmos". The New York Times. Associated Press. March 3, 2016. Retrieved March 10, 2016.
  9. ^ "GN-z11: Astronomers push Hubble Space Telescope to limits to observe most remote galaxy ever seen". Australian Broadcasting Corporation. March 3, 2016. Retrieved March 10, 2016.
  10. ^ "Hubble breaks cosmic distance record". SpaceTelescope.org. March 3, 2016. heic1604. Retrieved March 3, 2016.
  11. ^ "Hubble Team Breaks Cosmic Distance Record - Full". HubbleSite.org. March 3, 2016. STScI-2016-07. Retrieved March 3, 2016.
  12. ^ a b c d "Shattering the cosmic distance record, once again". Yale News. Retrieved March 4, 2016.
  13. ^ Hubble ESA, Garching, Germany (March 3, 2016). "Most distant galaxy: Hubble breaks cosmic distance record". Astronomy Magazine. Retrieved March 7, 2016. 'The previous record-holder was seen in the middle of the epoch when starlight from primordial galaxies was beginning to heat and lift a fog of cold hydrogen gas,' said Rychard Bouwens from the University of Leiden in the Netherlands. 'This transitional period is known as the reionization era. GN-z11 is observed 150 million years earlier, near the very beginning of this transition in the evolution of the universe.'{{cite web}}: CS1 maint: multiple names: authors list (link)
  14. ^ Hubble ESA, Garching, Germany (March 3, 2016). "Most distant galaxy: Hubble breaks cosmic distance record". Astronomy Magazine. Retrieved March 7, 2016. However, the discovery also raises many new questions as the existence of such a bright and large galaxy is not predicted by theory. 'It's amazing that a galaxy so massive existed only 200 million to 300 million years after the very first stars started to form. It takes really fast growth, producing stars at a huge rate, to have formed a galaxy that is a billion solar masses so soon,' said Garth Illingworth of the University of California in Santa Cruz.

    Marijn Franx, a member of the team from the University of Leiden said, 'The discovery of GN-z11 was a great surprise to us as our earlier work had suggested that such bright galaxies should not exist so early in the universe.' His colleague Ivo Labbe added: 'The discovery of GN-z11 showed us that our knowledge about the early universe is still restricted. How GN-z11 was created remains somewhat of a mystery for now. Probably we are seeing the first generations of stars forming around black holes?'{{cite web}}: CS1 maint: multiple names: authors list (link)

External links

Records
Preceded by Most distant known astronomical object
2016 – Present 		Current holder
Preceded by Most distant known galaxy
2016 – Present 		Current holder
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