Using images from the Hubble Space Telescope, astronomers have concluded that two of the most common types of galaxies in the universe are in reality different versions of the same thing. In spite of their similar-sounding names, astronomers had long considered “dwarf elliptical” and “giant elliptical” galaxies to be distinct objects. The new findings, which appear in this month’s edition of The Astronomical Journal, fundamentally alter astronomers’ understanding of these important components of the universe.
Artists impression of two black holes evacuating the center of a galaxy. Credit: Gabriel Perez Diaz; MultiMedia Service; Instituto de Astrofísica de Canarias (IAC).
Galaxies, the building blocks of the visible universe, are enormous systems of stars bound together by gravity and scattered throughout space. There are several different types, or shapes. For example, the Milky Way galaxy, in which the Earth resides, is a “spiral” galaxy, so named because its disk-like shape has an embedded spiral arm pattern. Other galaxies are known as “irregular” galaxies because they do not have distinct shapes. But together, dwarf and giant elliptical galaxies are the most common.
For the past two decades, astronomers have considered giant elliptical galaxies, which contain hundreds of billions of stars, and dwarf elliptical galaxies, which typically contain less than one billion stars, as completely separate systems. In many ways it was a natural distinction: not only do giant elliptical galaxies contain more stars, but the stars are more closely packed toward the centers of such galaxies. In other words, the overall distribution of stars appeared to be fundamentally different.
Alister Graham | alfa
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The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
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