Chandra Deep Field South

Coordinates: Sky map 03h 32m 28.0s, −27° 48′ 30″
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Chandra Deep Field South
A Pool of Distant Galaxies.jpg
The Chandra Deep Field South, observed in the U-, B-, and R-bands with Very Large Telescope's WFI and Visible Multi Object Spectrograph imagers.
Alternative namesCDF-S
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Three-colour composite image of the Chandra Deep Field South (CDF-S), obtained with the Wide Field Imager on the 2.2-m MPG/ESO telescope at the ESO La Silla Observatory (Chile).

The Chandra Deep Field South (CDF-S) is an image taken by the Chandra X-ray Observatory satellite. The location was chosen because, like the Lockman Hole, it is a relatively clear "window" through the ubiquitous clouds of neutral hydrogen gas in the Milky Way galaxy, which allows observers to clearly see the rest of the universe in X-rays.[1] The image is centered on RA 3h 32m 28.0s DEC −27° 48′ 30″ (J2000.0), covering 0.11 square degrees, measuring 16 arcminutes across. This patch of sky lies in the Fornax constellation.[2][3]

The image was created by compositing 11 individual ACIS-I exposures for a cumulative exposure time of over one million seconds, in the period 1999–2000, by a team led by Riccardo Giacconi.[2] This region was selected for observation because it has much less galactic gas and dust to obscure distant sources.[3] Further observations taken between 2000 and 2010 have resulted in a total of exposure of over four million seconds.[4] An additional four million seconds of exposure are scheduled to be undertaken by the end of 2015, resulting in an integrated exposure time of eight million seconds. The Chandra Deep Field South is the single target where Chandra has observed the longest.

Multispectral observations of the region were carried out in collaboration with the Very Large Telescope and the Paranal Observatory. Through the course of these investigations, the X-ray background was determined to have originated from the central supermassive black holes of distant galaxies, and a better characterization of Type II quasars was obtained.[Note 1] The CDFS discovered over 300 X-ray sources, many of them from "low luminosity" AGN lying about 9 billion light years away. The study also discovered the then most distant Type II quasar, lying at redshift z=3.7, some 12 billion light years away.[3]

In 2014 and 2015 astronomers detected four very intense burst of X-rays, currently unexplained, from a small galaxy, known as CDF-S XT1, about 11 billion light years from Earth in the Fornax constellation.[5]

See also[edit]


  1. ^ Type II quasars are quasars that are deeply embedded in dust and gas, from our point of view



  1. ^ "Chandra Deep Field South - Field Selection". Retrieved 12 December 2011.
  2. ^ a b Staff (March 2001). "ESO - The Chandra Deep Field South". Retrieved 10 October 2009.
  3. ^ a b c Staff (May 2001). "ESO Press Release 05/01 - Chandra and the VLT Jointly Investigate the Cosmic X-Ray Background". Archived from the original on 3 September 2007. Retrieved 10 October 2009.
  4. ^ "The Chandra Deep Field-South Survey". Archived from the original on 2015-02-20. Retrieved 2015-04-16.
  5. ^ Overbye, Dennis (31 March 2017). "A Mysterious Flash From a Faraway Galaxy". The New York Times. Retrieved 31 March 2017.

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