Galaxy Archives - Page 2 of 3 -
Some of the galaxies in our universe are veritable star nurseries. For example, our own Milky Way produces, on average, at least one new star every year. Others went barren years ago, now producing few if any new stars. Why that happens is a question that has dogged astronomers for years.
Many people change a lot after their youth… and so to did our Universe. Nowadays, galaxies contain both dust and gas, but back in the early Big-Bang days, the earliest galaxies had no dust, only gas. Now, A team of astronomers, led by Darach Watson, from the University of Copenhagen used the Very Large Telescope‘s X-shooter instrument along with the Atacama Large Millimetre/submillimetre Array (ALMA) to observe one of the youngest and most remote galaxies ever found.
Over 10 days in December 1995, the Hubble Space Telescope took 342 images of the same tiny patch of sky in the constellation Ursa Major. The resulting data set, the Hubble Deep Field, revolutionized the study of the early universe by revealing the profusion of galaxies in that faint and distant era when the first galaxies were forming.
Astronomers studying an otherwise “boring” galaxy over a billion light-years from Earth have been surprised to see a powerful storm erupt from its core, an event that will quench any new star formation in the foreseeable future.
A new study has revealed that some galaxies can die early because the gas they need to make new stars is suddenly ejected. Most galaxies stop growing when they run out of raw materials over billions of years. However, some galaxies seem to die young when they shoot out the gas they need early on.
For several years, astronomers have tried to develop the computer-simulated models of the Universe; but without the desired success. The galaxies formed in computer simulations were typically extremely massive, sometimes too small or too old. The computers would generate galaxies of very spherical shape; which haven’t been observed.
To a distant observer, our own Milky Way and the Andromeda galaxy would probably look very similar. Although Andromeda is longer, more massive, and more luminous than the Milky Way, both galaxies are vast spirals composed of hundreds of millions of stars.
The central regions of many glittering galaxies, our own Milky Way included, harbor cores of impenetrable darkness—black holes with masses equivalent to millions, or even billions, of suns. What is more, these supermassive black holes and their host galaxies appear to develop together, or “co-evolve.” Theory predicts that as galaxies collide and merge, growing ever more massive, so too do their dark hearts.
The Milky Way, the galaxy we live in, is part of a cluster of more than 50 others that make up the ‘Local Group’, a collection that includes the famous Andromeda Galaxy and many other far smaller objects. Now a Russian-American team have added to the canon, finding a tiny and isolated dwarf galaxy almost 7 million light-years away.
A team of astronomers has found an important new example of a very rare type of galaxy that may yield valuable insight on how galaxies developed in the early Universe. The new discovery technique promises to give astronomers many more examples of this important and mysterious type of galaxy.
The universe is vast, making it extremely difficult to measure distances between heavenly bodies. Currently, the most common method can measure relative distances, but researchers from the Niels Bohr Institute at the University of Copenhagen, the University of Southampton, and the Kyoto Sangyo University have found another way thanks to “Eye of Sauron.”
Quasars are the most luminous objects in the universe, beacons that shine across vast cosmological distances. They are galaxies that have particularly active supermassive black holes at their cores, objects surrounded by discs of extremely hot matter spiralling into oblivion and emitting bright beams of particles along their spin axes at nearly the speed of light.