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HD1

Coordinates: Sky map 10h 01m 51.31s, +02° 32′ 36.1″
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This is an old revision of this page, as edited by Omnissiahs hierophant (talk | contribs) at 13:24, 9 April 2022 (→‎Physical properties: consistent phrasing with prev adjustment). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

"HD1" redirects here. For other uses, see HD1 (disambiguation).
"HD2" redirects here. For other uses, see HD2 (disambiguation).

HD1 Galaxy
Three-color image of HD1, the most distant galaxy candidate to date (13.5 billion light years), created using data from the VISTA telescope in Hawaii. The red object in the center of the zoom-in image is HD1.[1]
Observation data (J2000 epoch)
ConstellationSextans[2][3]
Right ascension10h 01m 51.31s[2]
Declination02° 32′ 50.0″[2]
Redshift13.27[2]
Distance

HD1 is a purported high-redshift galaxy, and is considered, as of April 2022, to be the earliest and most distant known galaxy yet identified in the observable universe.

Discovery

The discovery of HD1 (RA:10:01:51.31 DEC:+02:32:50.0) in the Sextans constellation,[2][3] along with a related galaxy, HD2 (RA:02:18:52.44 DEC:-05:08:36.1) in the Cetus constellation,[2][3] was reported by astronomers at the University of Tokyo on 7 April 2022.

Physical properties

HD1 is the earliest and most distant known galaxy yet identified in the observable universe, having a spectroscopic redshift of z = 13.27, meaning that the light from the galaxy travelled for 13.5 billion years on its way to Earth, which due to the expansion of the universe, corresponds to a proper distance of approximately 33.4 billion light-years (10.2 billion parsecs).[1][2][4][5][6][7] The observed position of HD1 was determined to be about 330 million years after the Big Bang. Another similar high-redshift galaxy, HD2, was determined to be nearly as far away as HD1.[8]

HD1's unusually high brightness has been an open question for its discoverers; it having a significantly luminous ultraviolet emission. Possible explanations have been proposed, one being that it is an active Lyman-break galaxy, or a rather extreme starburst galaxy producing stars at a rate far higher than any previously observed. It is also considered that it may have a significant population of Population III stars that are far more massive and more luminous than present-day stars. Another scenario is that it may be a quasar hosting a supermassive black hole; such a scenario would put constraints on models of black hole growth in such an early stage of the universe. A resolution to the true nature of the galaxy would likely await confirmations from the James Webb Space Telescope.[9]

The previous farthest known galaxy, GN-z11, with a redshift of 11, suggesting that the observed position of the galaxy is about 420 million years after the Big Bang, was discovered in 2016.[8]

Future considerations

According to the discoverers of HD1 and HD2, "If spectroscopically confirmed, these two sources [ie, HD1 and HD2] will represent a remarkable laboratory to study the Universe at previously inaccessible redshifts."[5] The researchers expect even further clarification of the astronomical objects, including better identifying the objects as galaxies, or, possibly as quasars or black holes, when carefully examined by the upcoming James Webb Space Telescope, Nancy Grace Roman Space Telescope, and GREX-PLUS space missions.[2] HD1, on close examination, may also reveal the first visible Population III stars, due to its old age.[9] In addition, the researchers claim that use of the new upcoming space telescopes could help discover over 10,000 galaxies at this early epoch of the Universe.[8]

Earliest galaxy candidates and the history of the Universe (7 April 2022)[1]

See also

References

  1. ^ a b c Lira, Nicolás; Iono, Daisuke; Oliver, Amy c.; Ferreira, Bárbara (7 April 2022). "Astronomers Detect Most Distant Galaxy Candidate Yet". Atacama Large Millimeter Array. Retrieved 8 April 2022.
  2. ^ a b c d e f g h Harikane, Yuichi; et al. (2 February 2022). "A Search for H-Dropout Lyman Break Galaxies at z~12–16" (PDF). Arxiv. arXiv:2112.09141. Retrieved 7 April 2022.
  3. ^ a b c Staff (2008). "Finding the constellation which contains given sky coordinates". DJM.cc. Retrieved 8 April 2022.
  4. ^ a b c Crane, Leah (7 April 2022). "Astronomers have found what may be the most distant galaxy ever seen – A galaxy called HD1 appears to be about 33.4 billion light years away, making it the most distant object ever seen – and its extreme brightness is puzzling researchers". New Scientist. Retrieved 8 April 2022.
  5. ^ a b Pacussi, Fabio; et al. (7 April 2022). "Are the newly-discovered z ∼ 13 drop-out sources starburst galaxies or quasars?". Monthly Notices of the Royal Astronomical Society. doi:10.1093/mnrasl/slac035. Retrieved 7 April 2022.
  6. ^ Buongiorno, Caitlyn (7 April 2022). "Astronomers discover the most distant galaxy yet - Unusually bright in ultraviolet light, HD1 may also set another cosmic record". Astronomy. Retrieved 7 April 2022.
  7. ^ Wenz, John (7 April 2022). "Behold! Astronomers May Have Discovered The Most Distant Galaxy Ever – HD1 could be from just 300 million years after the Big Bang". Inverse. Retrieved 7 April 2022.
  8. ^ a b c Carlisle, Camille M. (7 April 2022). "Are These The Most Distant Galaxies Yet Seen? – Two fuzzy red objects in the early universe may be galaxies shining at us from only a few hundred million years after the Big Bang". Sky & Telescope. Retrieved 7 April 2022.
  9. ^ a b Overbye, Dennis (7 April 2022). "Astronomers Find What Might Be the Most Distant Galaxy Yet – Is the object a galaxy of primordial stars or a black hole knocking on the door of time? The Webb space telescope may help answer that question". The New York Times. Retrieved 7 April 2022.

External links

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