In astronomy, a deep field is an image of a portion of the sky taken with a very long exposure time, in order to detect and study faint objects. The depth of the field refers to the apparent magnitude or the flux of the faintest objects that can be detected in the image. Deep field observations usually cover a small angular area on the sky, because of the large amounts of telescope time required to reach faint flux limits. Deep fields are used primarily to study galaxy evolution and the cosmic evolution of active galactic nuclei, and to detect faint objects at high redshift. Numerous ground-based and space-based observatories have taken deep-field observations at wavelengths spanning radio to X-rays.

The first deep-field image to receive a great deal of public attention was the Hubble Deep Field, observed in 1995 with the WFPC2 camera on the Hubble Space Telescope. Other space telescopes that have obtained deep-field observations include the Chandra X-ray Observatory, the XMM-Newton Observatory, the Spitzer Space Telescope, and the James Webb Space Telescope.

Table

The following table gives a partial list of deep-field observations taken since 1995.

Image Name Telescope Year captured Size (arcminute) Number of exposures Hubble Deep Field Hubble Space Telescope 1995 2.6′x2.6′ 342 Hubble Deep Field South Hubble Space Telescope 1998 5.3²′ 995 Chandra Deep Field South Chandra X-ray Observatory 1999–2000 16′ across 11 Hubble Ultra-Deep Field Hubble Space Telescope 2003–2004 2.4′x2.4′ 808 Extended Groth Strip Hubble Space Telescope 2004–2005 70′x10′ over 500 Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) Hubble Space Telescope 2011 ESO's VLT and the SINFONI instrument Very Large Telescope 2012 Hubble eXtreme Deep Field Hubble Space Telescope 2012 2.3′x3′ Hubble Ultra-Deep Field (UV/VIS/NIR) Hubble Space Telescope 2014 Hubble Frontier Fields MACS J0416.1-2403 Hubble Space Telescope 2015 Hubble Frontier Fields Abell 2744 Hubble Space Telescope 2015 Hubble Frontier Fields MACS J0717.5+3745 Hubble Space Telescope 2015 Hubble Frontier Fields MACS J1149.5+2223 Hubble Space Telescope 2015 Hubble Frontier Fields Abell S1063 Hubble Space Telescope 2016 Hubble Frontier Fields Abell 370 Hubble Space Telescope 2017 Hubble Frontier Fields Abell 370 parallel field Hubble Space Telescope 2017 Hubble Deep UV (HDUV) Legacy Survey Hubble Space Telescope 2018 Hubble Legacy Field Hubble Space Telescope 2019 25′x25′ 7,500 Dark Energy Survey Víctor M. Blanco Telescope 2021 18.41′x9.64′ Webb's First Deep Field James Webb Space Telescope 2022 2.4′ across James Webb Space Telescope – JADES (James Webb Space Telescope Advanced Deep Extragalactic Survey)First Deep Field James Webb Space Telescope 2022 4-6′×12′ approx;(4′×6′ and 6′×6′ subsets adjacent) James Webb Space Telescope – JADES (James Webb Space Telescope Advanced Deep Extragalactic Survey) James Webb Space Telescope 2024 6′x4′ Euclid Deep Field North (EDF-N)Euclid2025-(data release 3)20 deg2DR3 visits: 40Euclid Deep Field South (EDF-S)Euclid2025-(data release 3)23 deg2DR3 visits: 45Euclid Deep Field Fornax (EDF-F), centred on Chandra Deep Field SouthEuclid2025-(data release 3)10 deg2DR3 visits: 52

See also

List of Hubble Space Telescope anniversary images

References