A galaxy that goes the distance.More brilliant than the galaxies that house them, quasars shine like beacons through the dark reaches of cosmic space. Indeed, these powerhouses are so bright that ever since their discovery in 1963, one or another of them has held court as the most distant visible body in the cosmos. Now, a galaxy has for the first time snared that title. Researchers estimate that the unnamed galaxy, detected by the Hubble Space Telescope Hubble Space Telescope (HST), the first large optical orbiting observatory. Built from 1978 to 1990 at a cost of $1.5 billion, the HST (named for astronomer E. P. Hubble) was expected to provide the clearest view yet obtained of the universe. , lies 13 billion light-years from Earth. This calculation assumes the universe is about 14 billion years old. Light now reaching Earth left the starlit star·lit adj. Illuminated by starlight. starlit Adjective lit by starlight Adj. 1. body when the cosmos was still in a formative stage. The galaxy might have gone undetected were it not for a cosmic mirage. According to Einstein's theory of general relativity, massive objects bend light, acting as gravitational lenses. One such lens is a cluster of galaxies cluster of galaxies Gravitationally bound grouping of galaxies, numbering from the hundreds to the tens of thousands. Large clusters of galaxies often exhibit extensive X-ray emission from intergalactic gas heated to tens of millions of degrees. that resides 5 billion light-years from Earth and happens to lie directly between the distant galaxy and our planet. The lensing makes the distant galaxy 5 to 10 times brighter, enabling astronomers to study details of starbirth in one of the youngest objects in the universe. The distorted, arclike shape of the object in Hubble images was a telltale sign that the light had been lensed. It was the galaxy's red color, however, that captivated cap·ti·vate tr.v. cap·ti·vat·ed, cap·ti·vat·ing, cap·ti·vates 1. To attract and hold by charm, beauty, or excellence. See Synonyms at charm. 2. Archaic To capture. Marijn Franx of the Kapteyn Institute in Groningen, Netherlands. The reddish hue indicates that the galaxy is very distant and has had much of its blue light absorbed by the vast amount of intergalactic in·ter·ga·lac·tic adj. Being or occurring between galaxies: intergalactic space. in hydrogen gas between it and Earth. Astronomers including Garth D. Illingworth of the University of California, Santa Cruz The University of California, Santa Cruz, also known as UC Santa Cruz or UCSC, is a public, collegiate university, one of the ten campuses of the University of California. verified the faraway location of the galaxy by measuring its redshift redshift Displacement of the spectrum of an astronomical object toward longer wavelengths (visible light shifts toward the red end of the spectrum). In 1929 Edwin Hubble reported that distant galaxies had redshifts proportionate to their distances (see , the amount by which its light is shifted to the red end of the spectrum. The more distant the galaxy, the greater the redshift. Spectra taken with one of the twin W.M. Keck telescopes atop Hawaii's Mauna Kea revealed that the galaxy has a redshift of 4.92, the highest of any object recorded to date. The previous record holder, the quasar PC 1247+34, has a redshift of 4.90 and lies a few tens of millions of light-years closer to Earth. Franx, Illingworth, and their colleagues report their find in the Sept. 10 Astrophysical Journal Letters. The Keck spectra also reveal that gas in the galaxy moves at some 200 kilometers per second, presumably pre·sum·a·ble adj. That can be presumed or taken for granted; reasonable as a supposition: presumable causes of the disaster. jazzed by a series of supernova explosions. Dense knots of massive stars indicate that the galaxy, seen in its infancy, blazes with a brilliance more than 10 times that of the Milky Way today. |
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