New study finds that supernova explosions and the jets of a monstrous black hole are scattering a galaxy’s star-making gas like a cosmic leaf blower. The findings, which relied on ultraviolet observations from NASA’s Galaxy Evolution Explorer and a host of other instruments, fill an important gap in the current understanding of galactic evolution. It has long been known that gas-rich spiral galaxies like our oun smash together to create elliptical galaxies such as the one observed in the study.
Scientists think that dark energy, the weird force blamed for propelling the universe to expand at an accelerated speed, probably turned on between 5 and 7 billion years ago. Now astronomers have mapped thousands of galaxies from this era, and have determined the most precise distances to them yet, in an effort to get to the bottom of the dark energy mystery. Dark energy is thought to represent about 74 percent of the universe’s total mass and energy, dwarfing ordinary matter.
The universe is filled with high-energy radiation, much of which is made of gamma rays belched out by strange pulsing stars and the remnants of supernova explosions. But nearly one-third of all gamma-ray emitting objects seen to date defy identification. The objects were spotted by NASA’s Fermi Gamma-ray Space Telescope, which scans the entire sky over the course of three hours, mapping the powerful spectrum.
An international team of researchers detected a so-called “normal-size” black hole in the distant galaxy Centaurus A, which is located about 12 million light-years away from Earth. By observing the black hole’s X-ray emissions as it gobbles material from its surrounding environment, the scientists determined that it is a low-mass black hole, one likely in the final stages of an outburst and locked in a binary system with another star.
The team of researchers from the University of Leicester (UK) and Monash University in Australia investigated how some black holes grow so fast that they are billions of times heavier than the sun. Professor Andrew King from the Department of Physics and Astronomy, University of Leicester, said that almost every galaxy has an enormously massive black hole in its center. Our own galaxy, the Milky Way, has one about four million times heavier than the sun.
An international team of astronomers from Australia, Germany, Switzerland, and Finland has discovered a rare dwarf galaxy, called LEDA 074886, which has a striking resemblance to an emerald cut diamond. The astronomers discovered the rectangular shaped galaxy within a group of 250 galaxies some 70 million light years away. As said Associate Professor Alister Graham from Swinburne University of Technology in the Universe around us, most galaxies exist in one of three forms: spheroidal, disc-like, or lumpy and irregular in appearance.
Astronomers by using NASA’s Hubble Space Telescope were able to find several examples of galaxies containing quasars, which act as gravitational lenses, amplifying and distorting images of galaxies aligned behind them. Quasars are among the brightest objects in the universe, far outshining the total starlight of their host galaxies. Quasars are powered by supermassive black holes. To find these rare cases of galaxy-quasar combinations acting as lenses, a team of astronomers led by Frederic Courbin at the Ecole Polytechnique Federale de Lausanne (EPFL, Switzerland) selected 23,000 quasar spectra in the Sloan Digital Sky Survey (SDSS).
Two teams of astronomers have used data from NASA’s Chandra X-ray Observatory and other telescopes to map the distribution of dark matter in a galaxy cluster known as Abell 383.Abell 383 is located about 2.3 billion light years from Earth. Researchers also able to determine how the dark matter is distributed along the line of sight. The recent work on Abell 383 provides one of the most detailed 3-D pictures yet taken of dark matter in a galaxy cluster. The X-ray data (purple) from Chandra in the composite image show the hot gas, which is by far the dominant type of normal matter in the cluster.
New observations which was made by using ESO’s Very Large Telescope will help to better understand the growth of teenage galaxies. In the biggest survey of its kind astronomers have found that galaxies changed their eating habits during their teenage years the period from about 3 to 5 billion years after the Big Bang. At the start of this phase smooth gas flow was the preferred snack, but later, galaxies mostly grew by cannibalising other smaller galaxies. Galaxies examined through the VLT are located in a tiny patch of sky more than 40 million light-years away, in the constellation of Cetus.