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The Sloan Digital Sky Survey or SDSS is a major multi-filter imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico begun in 2000. Image File history File links SDSS_logo. ...
Image File history File links SDSS_logo. ...
In astronomy, a redshift survey is a survey of a section of the sky to measure the redshift of astronomical objects. ...
The metre, or meter (U.S.), is a measure of length. ...
The Apache Point Observatory is located in the Sacramento Mountains in Sunspot, New Mexico (USA) 18 miles south of Cloudcroft. ...
Capital Santa Fe Largest city Albuquerque Area Ranked 5th - Total 121,665 sq mi (315,194 km²) - Width 342 miles (550 km) - Length 370 miles (595 km) - % water 0. ...
Named after the Alfred P. Sloan Foundation, it aims to map 25% of the sky and obtain observations on around 100 million objects and spectra for 1 million objects. The main galaxy sample has a median redshift of 0.1; there are redshifts for luminous red galaxies as far z=0.4, for quasars as far as z=5; and the imaging survey has been involved in the detection of quasars beyond a redshift 6. Cover of Time Magazine (December 27, 1926) Alfred Pritchard Sloan, Jr. ...
Redshift of spectral lines in the optical spectrum of a supercluster of distant galaxies (right), as compared with that of the Sun (left). ...
Redshift of spectral lines in the optical spectrum of a supercluster of distant galaxies (right), as compared with that of the Sun (left). ...
Artists impression of quasar GB1508 A quasar (contraction of QUASi-stellAR radio source) is an astronomical source of electromagnetic energy, including light, which shows a very high redshift. ...
Artists impression of quasar GB1508 A quasar (contraction of QUASi-stellAR radio source) is an astronomical source of electromagnetic energy, including light, which shows a very high redshift. ...
In the year 2006 the survey entered a new phase, the SDSS-II, by extending the obervations to explore the structure and stellar makeup of the Milky Way, the SEGUE and the Sloan Supernove Survey, which watches after supernovae Ia events to measure the distances to far objects.
Observations
SDSS uses a dedicated 2.5-m wide-angle optical telescope, and takes images using photometric system of five filters (named u, g, r, i and z). These images are processed to produce lists of objects observed and various parameters, such as whether they seem pointlike or extended (as a galaxy might) and how the brightness on the CCDs relates to various kinds of astronomical magnitude. Image File history File links SDSS_Telescope. ...
Image File history File links SDSS_Telescope. ...
In astronomy, a Photometric system is a set of discrete passbands (of filters), with a known sensitivity to incident radiation. ...
A specially developed CCD used for ultraviolet imaging in a wire bonded package. ...
// Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ...
The SDSS telescope uses the drift scanning technique [1], which lets the telescope fix and makes use of the earth's rotation to record small stripes of the sky. The image of the stars in the focal plane drifts along the CCD chip, instead of staying fixed as in tracked telescopes. This method allows consistent astrometry over the widest possible field and precision remains unaffected by telescope tracking errors. The disadvantages are minor distortion effects and the CCD has to be written and read in the same time. A specially developed CCD used for ultraviolet imaging in a wire bonded package. ...
The telescopes camera [2]is made up of thirty CCD chips each with a resolution of 2048x2048 pixels, totalling approximately 120 Megapixels. The chips are arranged in five rows of six chips. Each row has a different optical filter with wavelengths of 354, 476, 628, 769 and 925 nm up to a magnitude of respectively 24.4, 25.3, 25.1, 24.4 und 22.9 with a signal to noise ratio of 5. To enhance the sensitivity the camera is cooled to 190 Kelvin (about -80 degrees Celsius) by liquid nitrogen. This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as little squares and can easily be seen. ...
A pixel (a contraction of picture element) is one of the many tiny dots that make up the representation of a picture in a computers memory. ...
A metre (American spelling: meter; symbol: m) is a unit of length and the current base unit of length in the International System of Units (SI). ...
// Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ...
Signal to Noise (ISBN 1569711445)is a graphic novel by written by Neil Gaiman and illustrated by Dave McKean (Illustrator). ...
The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ...
 The Plug Plate for measuring spectra Using this data, targets are also selected for spectroscopy. The telescope is capable of recording 640 spectra at any one time by feeding an optical fibre for each through holes drilled in an aluminium plate. Each hole is individually positioned for the target in question. Per night about six to nine plates are used for recording spectra. Image File history File links SDSS_PlugPlate. ...
Image File history File links SDSS_PlugPlate. ...
Extremely high resolution spectrum of the Sun showing thousands of elemental absorption lines (fraunhofer lines) Spectroscopy is the study of matter and its properties by investigating light, sound, or particles that are emitted, absorbed or scattered by the matter under investigation. ...
Every night the telescope produces about 200 GBytes of data.
Sloan Legacy Survey The survey covers over 7,500 square degrees of the Southern Galactic Cap with data from nearly 2 million objects and spectra from over 800,000 galaxies and 100,000 quasars. This information of the position and distants of the objects allowed to investigate for the first time the large scale structure of the Universe with its voids and filaments.
SEGUE The Sloan Extension for Galactic Understanding and Exploration searches for the spectra of 240,000 stars with typical radial velocity of 10 km/s for obtaining the structure of the Milky Way and investigating the formation of components.
Sloan Supernova Survey Tries to find hundreds of Supernovae Ia until the year of 2007. The survey reapidly scans a 300 square degree area to detect variable objects and supernovae. For now it has detected 139 confimed Supernovae Ia events.
Data access
 The SkyServer Web Interface The survey makes the data releases available over the Internet. The SkyServer provides a range of interfaces to an underlying Microsoft SQL Server. Both spectra and images are available in this way, and interfaces are made very easy to use so that, for example, a full color image of any region of the sky covered by an SDSS data release can be obtained just by providing the coordinates. The SkyServer also provides a range of tutorials aimed at everyone from schoolchildren up to professional astronomers. The DR5[1], released June 2006, is the fifth major data release and provides images, imaging catalogs, spectra, and redshifts for download. Image File history File links Download high-resolution version (1024x768, 249 KB) http://cas. ...
Image File history File links Download high-resolution version (1024x768, 249 KB) http://cas. ...
Microsoft SQL Server is a relational database management system (RDBMS) produced by Microsoft. ...
The raw data (from before it was processed into databases of objects) is also available through another Internet server, and through the NASA World Wind program. USGS Urban Ortho-Imagery of Huntington Beach, Los Angeles in older version of World Wind (1. ...
Results Along with publications describing the survey itself, SDSS data has been used in publications over a huge range of astronomical topics. The SDSS website has a full list of these publications covering distant quasars at the limits of the observable universe, the distribution of galaxies, the properties of stars in our own galaxy and also subjects such as dark matter and dark energy in the universe. In astrophysics, dark matter is matter that does not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence may be inferred from its gravitational effects on visible matter. ...
In physical cosmology, dark energy is a hypothetical form of energy that permeates all of space and has strong negative pressure. ...
Notes - ^ David Rabinowitz (2005). "Drift Scanning (Time-Delay Integration)" (PDF). Retrieved on 2006-12-27.
- ^ Key Components of the Survey Telescope. SDSS (2006-08-29). Retrieved on 2006-12-27.
PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ...
The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
December 27 is the 361st day of the year in the Gregorian Calendar (362nd in leap years). ...
The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ...
December 27 is the 361st day of the year in the Gregorian Calendar (362nd in leap years). ...
See also Image File history File links Portal. ...
Cover of Time Magazine (December 27, 1926) Alfred Pritchard Sloan, Jr. ...
The Sloan Great Wall, a giant wall of galaxies, is the largest known structure in the Universe. ...
The Apache Point Observatory is located in the Sacramento Mountains in Sunspot, New Mexico (USA) 18 miles south of Cloudcroft. ...
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