The Deep Lens Survey (DLS, short for "Deep Gravitational Lensing Survey") is an ultra-deep

multi-band In telecommunications, a multi-band device (including (2) dual-band, (3) tri-band, (4) quad-band and (5) penta-band devices) is a communication device (especially a mobile phone) that supports multiple radio frequency bands. All devices which ha ...

optical survey of seven 4 square degree fields. Mosaic

CCD CCD may refer to: Science and technology * Charge-coupled device, an electronic light sensor used in various devices including digital cameras * .ccd, the filename extension for CloneCD's CD image file * Carbonate compensation depth, a property ...

imagers at the

National Optical Astronomy Observatory The National Optical Astronomy Observatory (NOAO) was the United States national observatory for ground-based nighttime ultraviolet-optical-infrared (OUVIR) astronomy. The National Science Foundation (NSF) funded NOAO to provide forefront astronom ...

Blanco Blanco (''white'' or ''blank'' in Spanish) or Los Blancos may refer to: People *Blanco (surname) Fictional characters *Blanco, a hobbit in J. R. R. Tolkien's Middle-earth *Blanco Webb, character in the BBC sitcom ''Porridge'' *Graboid#El Blanco, ...

( Cerro Tololo) and

Mayall telescope The Nicholas U. Mayall Telescope, also known as the Mayall 4-meter Telescope, is a four-meter (158 inches) reflector telescope located at the Kitt Peak National Observatory in Arizona and named after Nicholas U. Mayall. It saw first light on Fe ...

s (

Kitt Peak Kitt Peak () is a mountain in the U.S. state of Arizona, and at is the highest point in the Quinlan Mountains. It is the location of the Kitt Peak National Observatory. The radio telescope at the observatory is one of ten dishes comprising the ...

) are being used. The deep fields took five years to complete (2001–2006), in four bands: B, V, R, and z', to 29/29/29/28

mag Mag, MAG, Mags or mags may refer to: Arts, entertainment and media * ''MAG'' (video game), released in 2010 * ''Mág'' (film), a 1988 Czech film * ''Mag'' (Slovenian magazine), published from 1995 to 2010 * '' The Mag'', a British music magazin ...

per square

arcsecond A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...

surface brightness. Optical transient events (including moving objects such as

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

s and

comet A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...

s) and

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

candidates are released in real time.

Survey

The main goal of the survey is to produce unbiased maps of the large-scale structure of the mass distribution beyond the local universe, via very deep multicolor imaging of seven 2-degree fields and colour-

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and increase in frequency and e ...

s. The shear of distant

galaxies A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar Sys ...

induced by the

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

of foreground structures will be measured. These weak-lensing observations are sensitive to all forms of clumped mass and will yield unbiased mass maps with resolution of one

arcmin A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...

in the plane of the sky (about 120 kpc/ h at z = 0.2), in multiple redshift ranges. These maps will measure for the first time the change in large scale structure from z = 1 to the present epoch, and test the current theories of structure formation, which predict that mass in the low-redshift universe has a particular filamentary/sheetlike structure. These observations will directly constrain the clustering properties of matter, and, when compared with the results from

microwave background The cosmic microwave background (CMB, CMBR), or relic radiation, is microwave radiation that fills all space in the observable universe. With a standard optical telescope, the background space between stars and galaxies is almost completely dar ...

anisotropy Anisotropy () is the structural property of non-uniformity in different directions, as opposed to isotropy. An anisotropic object or pattern has properties that differ according to direction of measurement. For example, many materials exhibit ve ...

missions, will test the basic theory of structure formation via gravitational instability. While this is the main goal of the survey, a wide-field imaging survey has a myriad of other uses. In addition, the group is acquiring the data in a way which makes it possible to detect variable objects on scales of hours to months, by spreading observations of individual subfields over 4 runs over two years.

Discoveries

List of discovered minor planets

Galaxy clusters

References

External links

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