Editing Hubble Ultra-Deep Field (section)

{{Short description|Deep-field space image in Fornax, containing an estimate of 10,000 Galaxies}}
{{Sky|3|32|39.0|-|27|47|29.1|100000000000}}
[[File:Hubble ultra deep field high rez edit1.jpg|thumb|300px|The original NASA release, containing about 10,000 galaxies of various ages, sizes, shapes, and colors. The smallest, reddest ones are some of the most distant galaxies to have been imaged by an optical telescope, probably existing shortly after the [[Big Bang]].]]
{{multiple image |direction=horizontal |align=right |total_width=400
 |image1=NASA-Galaxies15k-HubbleHDUV-20180816.png |caption1=Hubble Deep UV (HDUV) Legacy Survey; 15k galaxies, released August 16, 2018
 |image2=Abyss lrgb v7 square.png |caption2=ABYSS WFC3/IR Hubble Ultra Deep Field; released January 24, 2019
}}

The '''Hubble Ultra-Deep Field''' ('''HUDF''') is a [[List of deep fields|deep-field]] image of a small region of [[outer space|space]] in the constellation [[Fornax]], containing an estimated 10,000 [[galaxies]]. The original data for the image was collected by the [[Hubble Space Telescope]] from September 2003 to January 2004 and the first version of the image was released on March 9, 2004.<ref name="press_release"/> It includes light from galaxies that existed about 13 billion years ago, some 400 to 800 million years after the Big Bang.

The HUDF image was taken in a section of the sky with a low density of bright stars in the near-field, allowing much better viewing of dimmer, more distant objects. Located southwest of [[Orion (constellation)|Orion]] in the southern-hemisphere constellation [[Fornax]], the rectangular image is 2.4 [[minute of arc|arcminutes]] to an edge,<ref>{{cite web|title=HubbleSite: Categories - news|url=http://hubblesite.org/newscenter/archive/releases/2009/31/fastfacts/|website=hubblesite.org|access-date=2014-02-26|archive-date=2016-11-11|archive-url=https://web.archive.org/web/20161111172740/http://hubblesite.org/newscenter/archive/releases/2009/31/fastfacts/|url-status=dead}}</ref> or 3.4 arcminutes diagonally. This is about one-tenth of the [[angular diameter]] of a full moon viewed from [[Earth]] (less than 34 arcminutes),<ref>{{cite web|title=Moon Illusion|url=http://homepages.wmich.edu/~korista/moon-illus.html|website=homepages.wmich.edu|access-date=2014-02-26|archive-date=2017-05-09|archive-url=https://web.archive.org/web/20170509115832/http://homepages.wmich.edu/~korista/moon-illus.html|url-status=dead}}</ref> smaller than a 1&nbsp;mm<sup>2</sup> piece of paper held 1&nbsp;m away, and equal to roughly one twenty-six-millionth of the total area of the sky. The image is oriented so that the upper left corner points toward north (−46.4°) on the [[celestial sphere]].

In August and September 2009, the HUDF field was observed at longer wavelengths (1.0 to 1.6&nbsp;μm) using the [[infrared]] channel of the recently fitted [[Wide Field Camera 3]] (WFC3). This additional data enabled astronomers to identify a new list of potentially very distant galaxies.<ref>{{cite web |url=http://hubblesite.org/newscenter/archive/releases/2009/31 |title=HubbleSite: News - Hubble's Deepest View of Universe Unveils Never-Before-Seen Galaxies |website=hubblesite.org}}</ref><ref name="Bouwens">{{cite journal |author-link1=Rychard Bouwens|first1=R.J. |last1=Bouwens|first2=G.D.|last2=Illingworth|first3=P.A. |last3=Oesch|first4=M. |last4=Stiavelli|first5=P. |last5=van Dokkum|first6=M. |last6=Trenti|first7=D. |last7=Magee|first8=I. |last8=Labbe|first9=M. |last9=Franx|author-link10=C. Marcella Carollo|first10=M. |last10=Carollo|first11=V. |last11=Gonzalez |arxiv=0909.1803 |title=Discovery of z~8 Galaxies in the HUDF from ultra-deep WFC3/IR Observations |journal=Astrophysical Journal |year=2009 |bibcode=2010ApJ...709L.133B |doi=10.1088/2041-8205/709/2/L133 |volume=709 |issue=2 |pages=L133–L137|s2cid=118083736 }}</ref>

On September 25, 2012, NASA released a new version of the Ultra-Deep Field dubbed the '''eXtreme Deep Field''' ('''XDF''').<!-- title now redirects to this one --> The XDF reveals galaxies from 13.2 billion years ago, including one thought to have formed only 450 million years after the Big Bang.<ref name="xdf">{{cite web |url=http://www.nasa.gov/mission_pages/hubble/science/xdf.html |title=Hubble Goes to the eXtreme to Assemble Farthest-Ever View of the Universe |date=September 25, 2012 |publisher=NASA |access-date=September 26, 2012}}</ref>

On June 3, 2014, NASA released the Hubble Ultra Deep Field 2014 image, the first HUDF image to use the full range of [[ultraviolet]] to [[near-infrared]] light.<ref name="NASA-20140603">{{cite web |url=http://www.iac.es/divulgacion.php?op1=16&id=1521&lang=en |title=IAC PRESS RELEASE - Making the Hubble's deepest images even deeper |date=January 24, 2019 |work=Instituto de Astrofísica de Canarias}}</ref> A composite of separate exposures taken in 2002 to 2012 with Hubble's Advanced Camera for Surveys and Wide Field Camera 3, it shows some 10,000 galaxies.<ref>{{Cite web|title=Hubble Ultra Deep Field 2014|url=http://hubblesite.org/contents/media/images/2014/27/3380-Image|access-date=2022-01-25|website=HubbleSite.org|language=en}}</ref>

On January 23, 2019, the [[Instituto de Astrofísica de Canarias]] released an even deeper version<ref>{{Cite web |url=http://www.iac.es/divulgacion.php?op1=16&id=1521&lang=en |title=Instituto de Astrofísica de Canarias - IAC - Educational Outreach |date=January 24, 2019 |website=www.iac.es |access-date=February 5, 2019}}</ref> of the infrared images of the Hubble Ultra Deep Field obtained with the WFC3 instrument, named the '''ABYSS Hubble Ultra Deep Field'''. The new images improve the previous reduction of the WFC3/IR images, including careful sky background subtraction around the largest galaxies on the field of view. After this update, some galaxies were found to be almost twice as big as previously measured.<ref>{{Cite journal |last1=Martínez-Lombilla |first1=Cristina |last2=Akhlaghi |first2=Mohammad |last3=Cardiel |first3=Nicolás |last4=Dorta |first4=Antonio |last5=Cebrián |first5=María |last6=Gómez-Guijarro |first6=Carlos |last7=Almagro |first7=Rodrigo Takuro Sato Martín de |last8=Lumbreras-Calle |first8=Alejandro |last9=Infante-Sáinz |first9=Raúl |date=January 1, 2019 |title=The missing light of the Hubble Ultra Deep Field |url=https://www.aanda.org/articles/aa/abs/2019/01/aa34312-18/aa34312-18.html |journal=Astronomy & Astrophysics |volume=621 |pages=A133 |doi=10.1051/0004-6361/201834312 |issn=0004-6361|arxiv=1810.10298 |bibcode=2019A&A...621A.133B |s2cid=119232262 }}</ref><ref>{{Cite journal |last1=Borlaff |first1=Alejandro |last2=Trujillo |first2=Ignacio |last3=Román |first3=Javier |last4=Beckman |first4=John E. |last5=Eliche-Moral |first5=M. Carmen |last6=Infante-Sáinz |first6=Raúl |last7=Lumbreras |first7=Alejandro |last8=de Almagro |first8=Rodrigo Takuro Sato Martín |last9=Gómez-Guijarro |first9=Carlos |date=January 2019 |title=The missing light of the Hubble Ultra Deep Field |journal=Astronomy & Astrophysics |volume=621 |pages=A133 |doi=10.1051/0004-6361/201834312 |issn=0004-6361|arxiv=1810.10298 |bibcode=2019A&A...621A.133B |s2cid=119232262 }}</ref>