quinta-feira, 12 de janeiro de 2012

The Sloan Digital Sky Survey

The Sloan Digital Sky Survey


The Sloan Digital Sky Survey (SDSS) is one of the most ambitious and influential surveys in the history of astronomy. Over eight years of operations (SDSS-I, 2000-2005; SDSS-II, 2005-2008), it obtained deep, multi-color images covering more than a quarter of the sky and created 3-dimensional maps containing more than 930,000 galaxies and more than 120,000 quasars.
SDSS data have been released to the scientific community and the general public in annual increments, with the final public data release from SDSS-II occurring in October 2008. That release, Data Release 7, is available through this website.
Meanwhile, SDSS is continuing with the Third Sloan Digital Sky Survey (SDSS-III), a program of four new surveys using SDSS facilities. SDSS-III began observations in July 2008 and released its first public data as Data Release 8 to emphasize its continuity with previous SDSS releases. SDSS-III will continue operating and releasing data through 2014.
Data Release 8 contains all images from the SDSS telescope - the largest color image of the sky ever made. It also includes measurements for nearly 500 million stars and galaxies, and spectra of nearly two million. All the images, measurements, and spectra are available free online. You can browse through sky images, look up data for individual objects, or search for objects anywhere in the sky based on any criteria.

The SDSS used a dedicated 2.5-meter telescope at Apache Point Observatory, New Mexico, equipped with two powerful special-purpose instruments. The 120-megapixel camera imaged 1.5 square degrees of sky at a time, about eight times the area of the full moon. A pair of spectrographs fed by optical fibers measured spectra of (and hence distances to) more than 600 galaxies and quasars in a single observation. A custom-designed set of software pipelines kept pace with the enormous data flow from the telescope. The two key technologies that enabled the SDSS, optical fibers and the digital imaging detectors known as CCDs, were the discoveries awarded the 2009 Nobel Prize in Physics.

During its first phase of operations, 2000-2005, the SDSS imaged more than 8,000 square degrees of the sky in five optical bandpasses, and it obtained spectra of galaxies and quasars selected from 5,700 square degrees of that imaging. It also obtained repeated imaging (roughly 30 scans) of a 300 square degree stripe in the southern Galactic cap.
With new financial support and an expanded collaboration including 25 institutions around the globe, SDSS-II carried out three distinct surveys:
The Sloan Legacy Survey completed the original SDSS imaging and spectroscopic goals. The final dataset includes 230 million celestial objects detected in 8,400 square degrees of imaging and spectra of 930,000 galaxies, 120,000 quasars, and 225,000 stars.

SEGUE (the Sloan Extension for Galactic Understanding and Exploration) probed the structure and history of the Milky Way galaxy, with new imaging of 3500 square degrees and spectra of 240,000 stars in a variety of categories in selected fields.

The Sloan Supernova Survey carried out repeat imaging of the 300 square degree southern equatorial stripe to discover and measure supernovae and other variable objects. In the course of three 3-month campaigns, the supernova survey discovered nearly 500 spectroscopically confirmed Type Ia supernovae, which are being used to determine the history of the accelerating cosmic expansion over the last 4 billion years.

SDSS data have supported fundamental work across an extraordinary range of astronomical disciplines, including the properties of galaxies, the evolution of quasars, the structure and stellar populations of the Milky Way, the dwarf galaxy companions of the Milky Way and M31, asteroids and other small bodies in the solar system, and the large scale structure and matter and energy contents of the universe; this site includes For a brief overview of SDSS science contributions. A more in-depth view can be found in the online materials from the 2008 Symposium The Sloan Digital Sky Survey: Asteroids to Cosmology.

terça-feira, 20 de dezembro de 2011

O PRIMEIRO DEVER PRESCRITO

O primeiro dever prescrito por Deus a Seus servos é o reconhecimento dAquele que é o Alvorecer de Sua Revelação e a Fonte de Suas leis, Aquele que representa a Deidade tanto no Reino de Sua Causa como no mundo da criação. Quem cumpre esse dever atinge todo o bem, e quem dele se priva conta-se entre os extraviados, mesmo que seja o autor de todos os atos retos. Cumpre a cada um que alcança esse mais sublime grau, esse ápice de transcendente glória, observar todos os mandamentos dAquele que é o Desejo do mundo. Esses deveres gêmeos são inseparáveis. Um não é aceitável sem o outro. Assim decretou Aquele que é o Manancial da inspiração divina.


Aqueles que Deus dotou de discernimento prontamente reconhecerão que os preceitos por Ele estabelecidos constituem os instrumentos supremos para a manutenção da ordem no mundo e a segurança de seus povos. Quem deles se desvia conta-se entre os abjetos e insensatos. Verdadeiramente, Nós vos ordenamos resistir aos ditames das vossas más paixões e desejos corruptos e não transpor os limites que a Pena do Altíssimo fixou, pois são o alento de vida para todas as coisas criadas. Os mares da sabedoria divina e das palavras de Deus encapelaram-se ao sopro da brisa do Todo-Misericordioso. Apressai-vos por saciar vossa sede, ó homens de compreensão!

Ó vós, povos do mundo! Sabei com certeza que Meus mandamentos são as lâmpadas de Minha amorosa providência entre os Meus servos e as chaves de Minha clemência para as Minhas criaturas. Eis o que se fez descer do céu da Vontade de vosso Senhor, o Senhor da Revelação. Se algum homem saboreasse a doçura das palavras que os lábios do Todo-Misericordioso decidiram pronunciar, ele renunciaria aos tesouros da terra, mesmo que os possuísse todos, a fim de vindicar a verdade de ao menos um dos Seus mandamentos, os quais se irradiam da Aurora de Sua benevolência e de Seu generoso cuidado.

domingo, 11 de dezembro de 2011

Prayer for the Dead

My laws appear like the sun in the heaven of Mine utterance

Everything that is hath come to be through His irresistible decree. Whenever My laws appear like the sun in the heaven of Mine utterance, they must be faithfully obeyed by all, though My decree be such as to cause the heaven of every religion to be cleft asunder. He doeth what He pleaseth. He chooseth, and none may question His choice. Whatsoever He, the Well-Beloved, ordaineth, the same is, verily, beloved. To this He Who is the Lord of all creation beareth Me witness. Whoso hath inhaled the sweet fragrance of the All-Merciful, and recognized the Source of this utterance, will welcome with his own eyes the shafts of the enemy, that he may establish the truth of the laws of God amongst men. Well is it with him that hath turned thereunto, and apprehended the meaning of His decisive decree.

quarta-feira, 7 de dezembro de 2011

obligatory prayer

We have enjoined obligatory prayer upon you, with nine rak'ahs, to be offered at noon and in the morning and the evening unto God, the Revealer of Verses. We have relieved you of a greater number, as a command in the Book of God. He, verily, is the Ordainer, the Omnipotent, the Unrestrained. When ye desire to perform this prayer, turn ye towards the Court of My Most Holy Presence, this Hallowed Spot that God hath made the Centre round which circle the Concourse on High, and which He hath decreed to be the Point of Adoration for the denizens of the Cities of Eternity, and the Source of Command unto all that are in heaven and on earth; and when the Sun of Truth and Utterance shall set, turn your faces towards the Spot that We have ordained for you. He, verily, is Almighty and Omniscient.

unsealed the choice Wine

Think not that We have revealed unto you a mere code of laws. Nay, rather, We have unsealed the choice Wine with the fingers of might and power. To this beareth witness that which the Pen of Revelation hath revealed. Meditate upon this, O men of insight!

terça-feira, 6 de dezembro de 2011

the sweet-smelling savour of My garment

Say: From My laws the sweet-smelling savour of My garment can be smelled, and by their aid the standards of Victory will be planted upon the highest peaks. The Tongue of My power hath, from the heaven of My omnipotent glory, addressed to My creation these words: "Observe My commandments, for the love of My beauty." Happy is the lover that hath inhaled the divine fragrance of his Best-Beloved from these words, laden with the perfume of a grace which no tongue can describe. By My life! He who hath drunk the choice wine of fairness from the hands of My bountiful favour will circle around My commandments that shine above the Dayspring of My creation.

segunda-feira, 5 de dezembro de 2011

O ye peoples of the world!

O ye peoples of the world! Know assuredly that My commandments are the lamps of My loving providence among My servants, and the keys of My mercy for My creatures. Thus hath it been sent down from the heaven of the Will of your Lord, the Lord of Revelation. Were any man to taste the sweetness of the words which the lips of the All-Merciful have willed to utter, he would, though the treasures of the earth be in his possession, renounce them one and all, that he might vindicate the truth of even one of His commandments, shining above the Dayspring of His bountiful care and loving-kindness.