A photometricredshift is an estimate for the distance of an astronomical object, such as a galaxy or quasar . The technique uses photometry astronomy photometry that is, the brightness of the object viewed through various standard filter optics filters , each of which lets through a relatively broad spectrum of colours, such as red light, green light, or blue light to determine the redshift , and hence, through Hubble s law , the distance, of the observed object. The technique relies upon the spectrum of radiation being emitted by the object having strong features that can be detected by the relatively crude filters. The technique was developed in the 1960s, ref The technique was first described by Baum, W. A. 1962, in G. C. McVittie ed. , Problems of extra galactic research , p. 390, IAU Symposium No. 15 ref but was largely replaced in the 1970s and 1980s by spectroscopic redshift s, using spectroscopy to observe the frequency or wavelength of characteristic spectral line s to see how far the lines were shifted from their usual position. The technique has come back into vogue as a result ... of high redshift objects. Photometric redshifts were originally determined by calculating the expected ... a spectroscopic redshift for each object, the technique of photometric spectroscopy provides a method to determine an at least qualitative characterization of a redshift. For example, if a Sun like spectrum had a redshift of z 1, it would be brightest in the infrared rather than at the yellow ... redshifts from photometric data. As photometric filters are sensitive to a range of wavelengths, and the technique ... arxiv.org abs astro ph 0003380 Photometric redshifts based on standard SED fitting procedures , Astronomy ... in the filter by a factor of two i.e. 1 z see K correction for more details on the photometric consequences of redshift . ref A pedagogical overview of the K correction by David Hogg and other ... manual1 node2.html What are photometric redshifts? Category Doppler effects astronomy stub it Spostamento ... more details
Ultra Deep Field , astronomers rely on a technique for measuring photometricredshift s. ref The technique ... on the photometric consequences of redshift. ref A pedagogical overview of the K correction by David ... to absorption lines in the optical spectrum of the Sun left . Arrows indicate redshift. Wavelength ... , redshift happens when light seen coming from an object that is moving away is Proportionality mathematics ... redshift due to the Doppler effect occurs whenever a light source moves away from an observer. Cosmology Cosmological redshift is seen due to the Metric expansion of space expansion of the universe ... show redshift corresponding to the rate of increase of their distance from Earth. Finally, gravitational redshift s are a general relativity relativistic effect observed in electromagnetic radiation moving ... relativity special relativistic Redshift formulae redshift formula and its classical physics classical approximation can be used to calculate the redshift of a nearby object when spacetime is Minkowski ..., the resulting changes are distinguishable from true redshift and not generally referred as such see ... transfer . Image Redshift blueshift.svg thumb Redshift and blueshift History The history of the subject ... , not motion Doppler would later be vindicated by verified redshift observations. The first Doppler redshift was described by French physicist Hippolyte Fizeau in 1848, who pointed to the shift ..., optical redshift was confirmed when the phenomenon was observed in Fraunhofer lines using solar rotation ... optical redshift in the laboratory using a system of rotating mirrors. ref cite journal author ... It thus becomes urgent to investigate the effect of the redshift and of the metric of the universe ... the redshift, one searches for features in the spectrum such as spectral line absorption lines , spectral ... wavelengths then the redshift can be calculated using the table below. Determining the redshift of an object in this way requires a frequency or wavelength range. In order to calculate the redshift ... more details
Infobox Album See Wikipedia WikiProject Albums Name The Redshift Type studio Artist Omnium Gatherum Cover Omnium Gatherum.jpg Released Start date 2008 09 22 Genre Melodic death metal Length 47 52 small standard edition small Label Candlelight Records Producer Dan Swan Reviews Allmusic Rating 3.5 5 Allmusic class album id r1416452 pure url yes Last album Stuck Here on Snakes Way br 2007 This album The Redshift br 2008 Next album New World Shadows br 2011 The Redshift is the fourth album from the Finnish melodic death metal band Omnium Gatherum . It is the band s second release for the Candlelight Records label. The album features a number of creative aspects not yet attempted by the band. A music video for the single Nail was released in Autumn 2008. It was shot in a monochromatic style. The album placed 24th in the Finnish heavy metal charts during 2008. Track listing tracklist title1 Nail length1 3 44 title2 A Shadowkey length2 4 29 title3 Chameleon Skin length3 4 56 title4 No Breaking Point length4 3 47 title5 The Return length5 5 28 title6 Shapes And Shades length6 4 51 title7 The Redshifter length7 3 41 title8 Greeneyes length8 4 39 title9 The Second Flame length9 4 24 title10 Song For December length10 2 19 title11 Distant Light Highway length11 5 34 External links http www.myspace.com omniumgatherum The RedShift at MySpace http www.omniumgatherum.org The RedShift at OmniumGatherum.org http www.metalfromfinland.com news 2008 09 14 11 56 omnium gatherum another new song posted online The RedShift at MetalFromFinland.com 2000s death metal album stub DEFAULTSORT Redshift Category Omnium Gatherum albums Category 2008 albums fi The Redshift ... more details
Image 2dfgrs.png right thumb 300px Rendering of the 2dFGRS data In astronomy , a redshift survey , or galaxy survey , is a astronomical surveys survey of a section of the sky to measure the redshift of astronomical objects. Using Hubble s law , the redshift can be used to calculate the distance of an object from Earth. By combining redshift with angular position data, a redshift survey maps the 3D distribution of matter within a field of the sky. These observations are used to measure properties of the Large scale structure of the cosmos large scale structure of the universe. The Great Wall astronomy Great Wall , a vast conglomeration of galaxies over 500 million light years wide, provides a dramatic example of a large scale structure that redshift surveys can detect. The first redshift survey was the CfA Redshift Survey , started in 1977 with the initial data collection completed in 1982. The most notable, recent and low redshift surveys are the 2dF Galaxy Redshift Survey , Sloan Digital Sky Survey and the Galaxy And Mass Assembly survey . At high redshift there exist the DEEP2 Redshift Survey and the VIMOS VLT Deep Survey VVDS . Because of the demands on observing time required to obtain spectroscopic redshifts i.e., true redshifts measured by velocity , it has become commonplace to use photometricredshift s, http astrowww.phys.uvic.ca grads gwyn pz index.html based on brightness. Such redshifts can be used in surveys and to find the space distribution of galaxies, provided the galaxy types are well known, but, obviously they cannot be used to define points on the Hubble curve, because of circular reasoning. External links http web.archive.org web 20050306033931 http cfa www.harvard.edu mwhite probes lss.html Probes of Large Scale Structure Category Physical cosmology Category Observational astronomy Category Large scale structure of the cosmos astronomy stub it Rilevamento degli spostamenti verso il rosso zh ... more details
Photometric stereo is a technique in computer vision for estimating the surface normals of objects by observing that object under different lighting conditions. The technique was originally introduced by Woodham in 1980. ref name Woodham1980 Woodham, R.J. 1980. Photometric method for determining surface orientation from multiple images. Optical Engineerings 19, I, 139 144. ref The special case where the data is a single image is known as shape from shading , and was analyzed by B. K. P. Horn in 1989. ref name BKPHorn89 B. K. P. Horn, 1989. Obtaining shape from shading information. In B. K. P. Horn and M. J. Brooks, eds., Shape from Shading, pages 121 171. MIT Press. ref Methods Under Woodham s original assumptions Lambertian reflectance , known point like distant light sources, and uniform albedo the problem can be solved by inverting the linear equation math I n cdot L math , where math I math is a known vector of math m math observed intensities, math n math is the unknown surface normal, and math L math is a known math 3 times m math matrix of normalized light directions. Photometric stereo has since been generalized to many other situations, including non uniform albedo, extended light sources, and non Lambertian surface finishes. ref cite web url http brl.ac.uk rwoodman files A Photometric Stereo Approach to Face Recognition.pdf title A Photometric Stereo Approach to Face Recognition publisher University of the West of England accessdate 2011 03 27 ref Current research aims to make the method work in the presence of projected shadows, highlights, and non uniform lighting. See also Photometry optics Photometry Stereo vision 3D scanner References Reflist Category Computer graphics Category Computer vision Category 3D imaging Compu graphics stub ... more details
In astronomy , a photometric system is a set of well defined passband s or filters , with a known sensitivity to incident radiation. The sensitivity usually depends on the optical system, detectors and filters used. For each photometric system a set of Photometric standard stars primary standard stars is provided. The first known standardized photometric system is the Johnson Morgan or UBV photometric system 1953 . At present, there are more than 200 photometric systems. Photometric systems are usually characterized according to the widths of their passbands broadband passbands wider than 30 nm, the most widely used is Johnson Morgan UBV system intermediate band passbands between 10 and 30 nm wide narrow band passbands less than 10 nm wide Photometric letters The letters designate a region of a wavelength of light. Majority of the letters span from near ultraviolet NUV to Visible spectrum visible and majority of the near infrared NIR . Note, indigo and cyan are not standard colors. ref http hyperphysics.phy astr.gsu.edu Hbase vision specol.html Spectral Colors ref Orange, yellow, and green fall under visual bands, while violet and purple are under the blue bands. Note, the letters are not standards, they are just recognized by astronomers and astrophysicists . class wikitable style text align center border collapse collapse cellpadding 2 Filter Letter Effective Wavelength ... 6 UBV photometric system OMC Johnson V filter 500 580 nm colspan 8 Optical Monitor Camera ref ... nm colspan 3 Str mgren photometric system UKIDSS WFCAM Z 882 nm Y 1031 nm J 1248 nm H 1631 nm K 2201 nm colspan 4 UKIRT Infrared Deep Sky Survey Vilnius photometric system ... colspan 2 Vilnius photometric system VISTA IRC Z 0.88 m Y 1.02 m J 1.25 m H 1.65 ... Database on Photometric Systems Michael S. Bessell 2005 , STANDARD PHOTOMETRIC SYSTEMS , Annual Reviews ..., H. Henning, Th. Stecklum, B., 2005 Category Photometric systems astronomy stub ca Sistema fotom tric ... more details
Wiktionary redshiftRedshift or red shift may refer to Science Redshift , the increase of wavelength of detected electromagnetic radiation with respect to the original wavelength of the emission Red shift, in solution spectroscopy is an informal term for bathochromic shift RedShift planetarium software RedShift planetarium software , planetarium software created by Maris Multimedia Technology Redshift theory , techno economic theory segmenting technology markets as either over or under served by Moore s Law Redshift, open source software that reduces eye strain by adjusting a screen s color temperature according to the time of day Music Red Shift Vierk Red Shift Vierk , a work by post minimalist composer Lois V Vierk Redshift music Redshift music , an English electronic music group Red Shift, an album released by the metal band Asgaroth A song by North Carolina hardcore band Hopesfall from the album The Satellite Years A song by Paradise Lost from the self titled album Paradise Lost Paradise Lost album Paradise Lost Redshift , an EP by Splashdown band Splashdown released on Capitol Records Red Shift , a song by Peter Hammill featuring Randy California , from his third album The Silent Corner and the Empty Stage Red Shift, a song by Toronto based industrial songstress Ayria Literature Red Shift novel Red Shift novel , a novel by Alan Garner Red Shift comics Red Shift comics , a fictional supervillan in the Marvel Comics universe and one of the Heralds of Galactus A poem by Ted Berrigan Red Shift Ltd, the name of the main industrial concern in the book by Samuel R. Delany, Nova novel Disambiguation de Redshift nl Redshift ... more details
Redshift quantization is the hypothesis that the redshift s of cosmologically distant objects in particular ... of cosmic distance ladder distance and redshift as expressed in Hubble s Law , redshift quantization ... with the redshift distance correlation, either of which would have serious implications for physical ... of redshift quantization as reason to reject the standard account of the origin and evolution ... 51 bibcode 1971AcPhH..30...51P doi ref . Recent redshift survey s of quasars QSOs have produced no evidence ... first1 M. B. last2 McDiarmid first2 D. year 2006 title Six Peaks Visible in the Redshift Distribution ... Redshift Model journal Astrophysical Journal volume 648 issue 1 pages 140 bibcode 2006ApJ...648..140B ... first2 K. last3 Flin first3 P. year 2006 title Weak redshift discretisation in the Local Group of galaxies ... S. M. last2 Zhang first2 S. N. year 2005 title Critical Examinations of QSO Redshift Periodicities ... most cosmologists dispute the existence of redshift quantization beyond a minimal trace due to the distribution of galaxies across voids and filaments. Redshift quantization has also been called redshift periodicity , ref cite journal last Tifft first W. G. year 2006 title Redshift periodicities ... 429 bibcode 2003Ap&SS.285..429T doi 10.1023 A 1025457030279 ref redshift discretization , ref cite ... tend to be strong X ray and radio emitters, and their redshifts occur at preferred redshift values. ref and redshift magnitude bands . ref cite journal last Tifft first W. G. year 1973 title Properties of the redshift magnitude bands in the Coma cluster journal Astrophysical Journal volume 179 ... of the redshift magnitude band phenomenon in the Coma Cluster journal Astronomy and Astrophysics ... G. Tifft William G. Tifft was the first to investigate possible redshift quantization, or redshift ... 1980 title Periodicity in the redshift intervals for double galaxies journal Astrophysical Journal ... of galaxies Coma galaxies on a single band is presented, which shows a strong redshift periodicity ... more details
Redshift are a United Kingdom British electronic music group, founded in 1996 by Mark Shreeve . Their musical style ranges from Berlin School of electronic music Berlin School to dark ambient . Their sound is largely dependent upon older synthesiser technology, notably instruments such as the Moog synthesizer Moog 3C which they combine with more recent digital technology. Lineup The lineup of the band currently consists of Mark Shreeve , Julian Shreeve , and Ian Boddy . Former band members were Rob Jenkins who departed the band in 2002, and James Goddard who has been unable to perform as part of Redshift due to other commitments since 2006. ref name interview2010 http www.musiczeit.com xtra hj9 HJ9prog view.pdf , Interview with Mark Shreeve, 2010. ref Discography Studio and Live Albums Redshift 1996, studio album remastered 2006 Ether 1998, live and studio album remastered 2007 Down Time 1999, studio album remastered 2007 Siren 2002, live album remastered with additional track 2007 Halo 2002, studio album remastered 2007 Wild 2002, live and studio album Faultline 2004, live album Oblivion 2004, studio album remastered 2007 Toll 2006, live album Wild 2 2006, live and studio album Last 2007, live album Turning Towards Us 2008, studio album Wild 3 2009, live and studio album Colder 2011 ... Kingdom 2004 Concerts Redshift live performances are rare due to the expense and logistics involved ... 2003.htm , Interview with Mark Shreeve, 2003. ref As of 2011, Redshift have performed a total .... Take the first letter of the albums Redshift, Ether, Down Time, Siren, Halo, Faultline and Toll. The remaining ... known for their joint project ARC . External links http www.redshift.biz The Official Redshift Website http www.musiczeit.com directory.php?artist 81&title RedshiftRedshift at MusicZeit Allmusic class artist id p20517 pure url yes AMG entry for Mark Shreeve Redshift http www.groove.nl cd 2 20083.html ... DEFAULTSORT Redshift Category Ambient music groups UK band stub de Redshift Band nl Redshift ... more details
The redshift rocket , envisaged by novelist Karl Schroeder , is a fictional method of spacecraft propulsion . It is a variant on the S nger antimatter rocket . One of the key difficulties of harnessing the energy from matter antimatter collisions is that most of the energy released by them is in the X ray and gamma ray spectrum. The redshift rocket proposes to use particle beam s, such as those produced by ultrafast laser pulses. Both the matter and antimatter would be accelerated to near light speed away from the spacecraft before colliding in the reaction chamber. This would lead to the radiation that reaches the spacecraft being redshift ed. If the speed of the particle beams is great enough, the radiation that hits the spacecraft will be of a frequency that can be reflected. Energy absorbed by the spacecraft could be used to help power the particle beams. But as a result only a very small fraction of the matter antimatter annihilation reaction would contribute to the propulsion and the main source of thrust would be the particle beams themselves, which must be generated by other means. Category Spacecraft propulsion ... more details
developers. The biggest selling point of Quantum Redshift was the graphics detail it possessed. Water ... Redshift was rated as one of the most graphically advanced games for the Xbox . External links Official website http www.xbox.com en US games q quantumredshift moby game id quantum redshift name Quantum Redshift Category Microsoft games Category Xbox games Category Xbox only games Category Racing ... in the United Kingdom Racing videogame stub es Quantum Redshift it Quantum Redshift ... more details
Dablink For other uses of redshift or red shift , see redshift disambiguation . Redshift is a techno economic theory suggesting hypersegmentation Clarify date June 2011 of Information technology Information Technology IT markets based on whether individual computing needs are over or under served by Moore s law Moore s Law , which predicts the doubling of computing transistors and therefore roughly computing power every two years. The theory, proposed and named by Sun Microsystems CTO Greg Papadopoulos , categorizes a series of high growth markets Redshifting while predicting slower GDP driven growth in traditional computing markets Blueshifting . Papadopoulos predicts the result will be a fundamental redesign of components comprising computing systems. Hypergrowth market segments Redshifting According to the Redshift theory, applications redshift when they grow dramatically faster than Moore ...?c us&l en&s corp ref While various Redshift proponents offer minor alterations on the original presentation ..., such as Salesforce.com , grow faster than Moore s Law. The eBay crisis A prime example of redshift ... Markets Blueshifting Redshift theory suggests that traditional computing markets, such as those ... growth, which roughly translates into computing power doubling every two years, the Redshift theory ... presentation on Redshift to Sun s annual Analyst Summit ref name gregspeech in February 2007. The term Redshift refers to what happens when electromagnetic radiation, usually visible light, moves away from an observer. Papadopoulos chose this term to reflect growth markets because redshift helped cosmologists ...&hl false Greg Papadopoulos Original Redshift presentation video http www.sun.com greg Official ... InformationWeek feature story on Redshift http www.roughtype.com archives 2007 02 the future of c.php ... s Jim Hamilton paper and presentation http blogs.zdnet.com BTL ?p 4477 ZDnet Blog on Redshift DEFAULTSORT Redshift Theory Category Adages Category Rules of thumb Category Computer industry Category ... more details
File Gravitational red shifting2.png thumb 200px The gravitational redshift of a light wave as it moves ... redshift or Einstein shift is the process by which electromagnetic radiation originating from a source that is in gravitational field is reduced in frequency , or redshift ed, when observed in a region ... is reduced towards the red part of the light spectrum, giving this phenomena the name redshift . Definition Redshift is often denoted with the dimensionless variable math z , math , defined as the fractional ... of emission. The gravitational redshift of a photon can be calculated in the framework of General ... the photon is emitted. The redshift is evaluated in at a distance in the limit going to infinity ... is emitted at a distance equal to the Schwarzschild radius, the redshift will be infinitely large. When the photon is emitted at an infinitely large distance, there is no redshift. The redshift is not defined ... large compared to the Schwarzschild radius math r s math , the redshift becomes math lim ... gravitational potential in order for gravitational redshift to be observed. In other words, the observer ... continue to support the existence of gravitational redshift. ref http hyperphysics.phy astr.gsu.edu hbase relativ gratim.html General Relativity ref Gravitational redshift is not only predicted by general relativity . Other theories of gravitation require gravitational redshift, although their detailed ... conservation of energy and mass energy equivalence must include gravitational redshift. Gravitational redshift does not assume the Schwarzschild metric solution to Einstein s field equation ... the gravitational redshift in spectral lines using a terrestrial Iron 57 sup 57 sup Fe gamma ... Gravitational redshift is studied in many areas of astrophysics astrophysical research. Exact Solutions ... equation for gravitational redshift applies to the case outside of a non rotating, uncharged mass which ... of light . Gravitational redshift versus gravitational time dilation When using special relativity ... more details
Unreferenced date July 2009 Photometric standard stars are a series of star s that have had their light output in various passbands of photometric system , measured very carefully. Other objects can be observed using Charge coupled device CCD cameras or photoelectric photometers connected to a telescope , and the flux , or amount of light received, can be compared to a photometric standard star to determine the exact brightness, or stellar magnitude , of the object. Citation needed date July 2009 The current set of photometric standard stars for UBVRI photometry most often used by astronomers Or date July 2009 is that published by Arlo U. Landolt in 1992 in the Astronomical Journal , vol. 104, no. 1, p. 340 371. Citation needed date July 2009 DEFAULTSORT Photometric Standard Stars Category Stars Category Star types Category Photometric systems astronomy stub pt Estrela padr o fotometria ... more details
Orphan date February 2009 In Photometry astronomy astronomical photometry , the Ultraviolet and Optical Telescope UVOT on the Swift Gamma Ray Burst Mission observes astronomical objects in its 17 by 17 arc minute field of view through one of several filters or grisms. The seven filters, which are similar to those on the XMM Newton OM instrument, cover the near ultraviolet and optical range. The brightness of an object observed in the three optical filters, called u, b, and v, can be converted into the more common Morgan Johnson see the UBV photometric system magnitudes. The three ultraviolet filters probe a spectral region that is not observable from the ground. Although the main mission is to chase gamma ray bursts as soon as they occur, many other transient celestial sources and other objects in the field of view are being measured. The filters, not being like any other Photometric system in use from the ground or in space, give unique photometric measurements. Their response has been defined as the UVOT photometric system, as outlined by ref T.S. Poole et al. Photometric calibration of the Swift ultraviolet optical telescope, MNRAS, 383, 627 ref . See also Stellar classification References references DEFAULTSORT Swift UVOT Photometric System Category Photometric systems astronomy stub ms Sistem fotometrik UBV ja u30b8 u30e7 u30f3 u30bd u30f3 u306eUBV u30b7 u30b9 u30c6 u30e0 pt Sistema fotom trico UBV sk UBV syst m zh UBV u6d4b u5149 u7cfb u7edf ... more details
Str mgren photometric system uvby sometimes also referred as Str mgren Crawford photometric system is four colour medium band photometric system plus H beta filters for stellar classification. It was pioneered by the Danish astronomer Bengt Str mgren in 1956 and extended by his colleague the American astronomer David L. Crawford in 1958. Mean wavelength and half widths of response functions border 1 cellspacing 0 cellpadding 8 bgcolor FFFFCC u v b y sub narrow sub sub wide sub bgcolor FFFFEE align center bgcolor FFFFCC Peak wavelength nm align center 350 align center 411 align center 467 align center 547 align center 485.8 align center 485 align center bgcolor FFFFCC Half width nm align center 30 align center 19 align center 18 align center 23 align center 2.9 align center 12.9 Indices b y, m sub 1 sub , c sub 1 sub , m sub 1 sub v b b y c sub 1 sub u v v b sub narrow sub sub wide sub y magnitudes are well correlated with UBV system Johnson Morgan V magnitude s. b y is sensitive to stellar temperature measure of Pashen continuum . c sub 1 sub is sensitive to the surface gravity measures Balmer discontinuity strength . m sub 1 sub is sensitive to the metallicity measure of line blanketing . References Str mgren, Bengt, 1956, http adsabs.harvard.edu cgi bin nph bib query?bibcode 1956VA......2.1336S& db key AST& data type HTML& format & high 44b52c369005903 Two dimensional spectral classification of F stars through photoelectric photometry with interference filters , Vistas in Astronomy, Vol. 2, Issue 1, pp. 1336&ndash 1346 Crawford, David L., 1958 ... 206 External links http ulisse.pd.astro.it Astro ADPS Systems index.html The Asiago Database on Photometric Systems http obswww.unige.ch gcpd ph04.html The uvby photometric system http www.optecinc.com pdf stromgren tutorial.pdf Stromgren photometric system tutorial See also Stellar classification Category Photometric systems astronomy stub it Sistema fotometrico uvby fi Uvby uk ... more details
wikinews Huge star cluster discovered in neighbourhood of Milky Way The photometric parallax method is a method of data analysis used in astronomy that uses the colours and apparent brightnesses of stars to infer their distances. It was used by the Sloan Digital Sky Survey to discover the Virgo super star cluster . Unlike the stellar parallax method, photometric parallax can be used to estimate the distances of stars over 10 kpc away, at the expense of much more limited accuracy for individual measurements. Strictly speaking, it does not actually employ any measurements of parallax and can be considered a misnomer. References cite journal author Mario Juric et al. title The Milky Way Tomography with SDSS year 2005 doi 10.1086 523619 journal The Astrophysical Journal volume 673 issue 2 pages 864 914 arxiv astro ph 0510520 See also Spectroscopic parallax Dynamical parallax Category Astrometry zh ... more details
UBV photometric system , also called the Harold Johnson astronomer Johnson system or Johnson Morgan system , is a wide band photometric system for Stellar classification classifying stars according to their colors. It is the first known standardized photoelectric photometric system . The letters U, B, and V stand for ultraviolet , blue, and visual magnitudes, which are measured for a star in order to classify it in the UBV system. ref Johnson, H. L. Morgan, W. W. 1953 , Fundamental stellar photometry for standards of spectral type on the revised system of the Yerkes spectral atlas , The Astrophysical Journal, vol. 117, pp. 313 352. http adsabs.harvard.edu abs 1953ApJ...117..313J ref The choice of colors on the blue end of the spectrum is because of the bias that photographic film has for those colors. It was introduced in the 1950s by United States American astronomer s Harold Johnson astronomer Harold Lester Johnson and William Wilson Morgan . The filters are selected in such manner, that the mean wavelengths of response functions are 364 nm for U, 442 nm for B, 540 nm for V. The zero point of the B V color B V and U B color index color indices was defined to be zero for A0 V stars not affected by interstellar reddening . The UBV system has some disadvantages. The short wavelength cutoff of the U filter is defined mainly by the terrestrial atmosphere rather than the filter itself. Thus, it and observed magnitudes can vary with altitude and atmospheric conditions. However, a large number of measurements have been made in this system, including many of the bright stars. ref Iriarte, Braulio, Johnson, Harold L., Mitchell, Richard I., and Wisniewski, Wieslaw K. 1965 , Five Color Photometry of Bright Stars , Sky & Telescope, vol. 30, p. 21 ref See also Portal Star Photometric system Stellar classification References references Star DEFAULTSORT Ubv Photometric System astronomy stub Category Photometric systems Category American inventions de UBV System fr Syst me ... more details
The Vilnius photometric system is a medium band seven colour photometric system UPXYZVS , created in 1963 by Vytautas Strai ys and his coworkers. This system was highly optimized for Stellar classification classification of stars from ground based observations. The system was chosen to be medium band, to ensure the possibility to measure faint stars. Selection of bandpasses The temperature classification of early type stars is based on Balmer jump Balmer discontinuity . To measure it one must have two bandpass es placed in the ultraviolet , one beyond the Balmer jump U magnitude and another after the jump X magnitude . The Y bandpass is near the breakpoint of the interstellar extinction law interstellar extinction in the 300&ndash 800 nm region can be approximated by two straight lines, which intersect at 435.5 nm . The P magnitude is placed exactly on the Balmer jump in order to provide separation for luminosity class es of B A F stars. The Z magnitude is placed on the magnesium Mg I Spin triplet triplet and the MgH molecular band . It is sensitive to the luminosity class es of G K M stars. Finally, the V magnitude is chosen to coincide with a similar bandpass in the UBV system . It provides the possibility to relate these two photometric systems. S bandpass coincides with H alpha line position and provides information about emission or absorption phenomena in that line. Normalization Colour indices of the system were normalized to satisfy the condition U P P X X Y Y Z Z V V S 0 for unreddened O type stars. Mean wavelength and half widths of response functions border 1 cellspacing 0 cellpadding 8 bgcolor FFFFCC U P X Y Z V S bgcolor FFFFEE align center bgcolor FFFFCC Mean wavelength nm align center 345 align center 374 align center 405 align center 466 align center ... also UBV photometric system References Vytautas Straizys Straizys V. , Multicolor Stellar Photometry , Pachart Pub. House, 1992, 570 pages. Category Photometric systems Category Science and technology ... more details
Redshift is planetarium software created by Maris Multimedia . It runs on PC with Microsoft Windows and iPad . Description This needs to be further refined and copyedited, perhaps with references. Redshift is a group of educational planetarium and astronomy software packages that allow the user to observe the sky from a range of dates, print off data based on the observations and in some versions control a telescope. It uses data from the Hubble Guide Star Catalog II. Began in the early 1990 s, the current version is 7.0 released in 2009 which includes 3D models of the galaxy, multimedia tours and access to star catalogs. Platforms include Windows 7 Vista XP , iPhone and iPad, PC editions include Premium with a library of 100 million objects and telescope control and Compact fewer objects in the library, no telescope interface . All version support Redshift Live links an online site to share observation information and other astronomy pictures and data. See also Cartes du Ciel Celestia Digital Universe Atlas Google Mars Google Moon Google Sky HNSKY Hallo Northern Sky HN Sky KStars Starry Night planetarium software Starry Night Stellarium computer program Stellarium TheSky astronomy software TheSky Universe Sandbox Worldwide Telescope XEphem External links http www.redshift live.com index.php en RedShift live Category Planetaria Category Astronomy software software stub be RedShift ru RedShift ... more details
The DEEP2 Survey or DEEP2 is a Redshift survey of the Redshift 1 universe. It uses the Keck telescopes the world s largest optical telescope As of 2005 lc on to measure the spectra and hence redshifts of approximately 60,000 galaxies. It is the first project to study galaxies in the distant Universe with the resolution of local surveys like Sloan Digital Sky Survey . External links http deep.berkeley.edu marc deep index.html DEEP2 Website UCB http deep.ucolick.org overview.html DEEP1 DEEP2 Website UCSC galaxy stub Category Astronomical surveys Category Physical cosmology zh 2 ... more details
The Las Campanas Redshift survey Redshift Survey is considered the first attempt to map a large area of the universe out to a redshift of z 0.2. It was begun in 1991 using the Las Campanas telescope in Chile to catalog 26418 separate galaxies. ref http qold.astro.utoronto.ca lin lcrs.html Las Campanas Redshift Survey web page ref It is considered one of the first surveys to document the so called end of greatness where the Cosmological Principle of isotropy could be seen. Supercluster s ref cite journal author Sergei F. Shandarin Shandarin, Sergei F. Capp Yess Yess, Capp title Detection of Network Structure in the Las Campanas Redshift Survey journal The Astrophysical Journal year 1998 volume 505 issue 1 pages 12 17 arxiv astro ph 9705155 doi 10.1086 306135 bibcode 1998ApJ...505...12S ref ref cite journal author Somnath Bharadwaj Bharadwaj, S. A. K. Gupta Gupta, A. K. T. R. Seshadri Seshadri, T. R. title Nature of clustering in the Las Campanas redshift survey journal Astronomy and Astrophysics year 1999 volume 351 pages 405 412 arxiv astro ph 9903252 bibcode 1999A&A...351..405B ref ref cite journal author Einasto, J. Einasto, M. H tsi, G. Saar, E. Tucker, D. L. Tago, E. M ller, V. Hein m ki, P. Allam, S. S title Clusters and Superclusters in the Las Campanas Redshift Survey journal Astronomy and Astrophysics year 2003 volume 410 issue 2 pages 425 443 bibcode 2003A&A...410..425E doi 10.1051 0004 6361 20031105 arxiv astro ph 0304546 ref ref cite journal author Somnath Bharadwaj Bharadwaj, S. , Varun Sahni Sahni, V. , B.S. Sathyaprakash Sathyaprakash, B.S. , Sergei F. Shandarin Shandarin, Sergei F. , Capp Yess Yess, Capp title Evidence for Filamentarity in the Las Campanas Redshift Survey journal The Astrophysical Journal year 2000 volume 528 issue 1 pages 21 29 bibcode 2000ApJ...528...21B doi 10.1086 308163 arxiv astro ph 9904406 ref and Galaxy void voids are prominent features in the survey. References reflist Category Observational astronomy astronomy stub ... more details
objects with a redshift mostly within less than z 0.3 and a median redshift of 0.11. The volume of the Universe ... 0 sub is approximately 70 km s Mpc. The largest redshift observed by the survey corresponds to a distance ... Redshift Survey. The 2dF survey also yields a unique view on our local cosmic environment. In the figure ... Redshift Survey http www2.aao.gov.au 2dFGRS Public Publications colless specz.pdf The 2dF Galaxy Redshift ... radd es 2dF Galaxy Redshift Survey fr 2dF Galaxy Redshift Survey ja 2dF zh 2 ... more details
The Center for Astrophysics CfA Redshift Survey was the first attempt to map the large scale structure of the universe. It began in 1977 with the initial data collection completed in 1982. ref http cfa www.harvard.edu huchra zcat CfA Redshift Survey and Catalog Retrieved April 7, 2007 ref Data from the second CfA survey 1985 95 made possible the 1989 discovery of the Great Wall astronomy Great Wall , a supercluster of galaxy galaxies ref http www.sciencemag.org cgi content abstract 246 4932 897 M. J. Geller & J. P. Huchra, Science 246, 897 1989 Retrieved April 7, 2007 ref surrounded by voids that surprised astronomers because its size was larger than what could be produced by gravitational collapse since the Age of the Universe beginning of the universe . Since then, superclusters have been described as artifacts of quantum fluctuation s in the cosmic inflation inflationary epoch of the universe. Astronomy stub References references Category Observational astronomy Category Large scale structure of the cosmos Category Astronomical surveys ar CfA fr CfA Redshift Survey ja CfA zh CfA ... more details
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