According to astronomers at the University of Bonn in Germany, who made the discovery, the structure of satellite galaxies and star clusters around the Milky Way is so vast that it reaches across a million light-years 10 times as wide as the Milky Way itself. Existing dark matter theories fail to explain the arrangement of these cosmic objects. As said study team member Pavel Kroupa, a professor of astronomy at the University of Bon their model appears to rule out the presence of dark matter in the universe, threatening a central pillar of current cosmological theory.
While some galaxies are rotund and others are slender disks like our spiral Milky Way, new observations from NASA’s Spitzer Space Telescope show that the Sombrero galaxy is both. The galaxy, which is a round elliptical galaxy with a thin disk embedded inside, is one of the first known to exhibit characteristics of the two different types. As said Dimitri Gadotti of the European Southern Observatory in Chile the Sombrero is more complex than previously thought.
These bright stars shining through what looks like a haze in the night sky are part of a young stellar grouping in one of the largest known star formation regions of the Large Magellanic Cloud (LMC), a dwarf satellite galaxy of the Milky Way.The LMC is the third closest galaxy to our Milky Way. It is located some 160 000 light-years away, and is about 100 times smaller than our own. The image was captured by the NASA/ESA Hubble Space Telescope’s Wide Field Planetary Camera 2.
Cosmic rays are charged subatomic particles that streak to Earth from deep in outer space. A few rare cosmic rays are extraordinarily powerful, with energies up to 100 million times greater than any attained by human-made particle colliders, such as CERN’s Large Hadron Collider. The sources of these cosmic rays are a mystery. According to study co-author Francis Halzen at the University of Wisconsin-Madison, principal investigator at the IceCube Neutrino Observatory, a massive telescope designed to find the tiny subatomic particles nature is capable of accelerating elementary particles to macroscopic energies.
New photo from the Hubble Space Telescope has captured an unprecedented panoramic view of the Tarantula nebula, revealing its bright heart of massive stars. The photo is actually a colossal mosaic, one of the largest ever built from Hubble images, and shows an intense star-forming hotspot called 30 Doradus. Hubble’s science team unveiled this new image on April 17. Hubble’s new view of the region inside the Tarantula nebula shows massive stars’ winds carving cavities into gas clouds, creating a fantasy landscape of pillars, ridges and valleys.
With the help the data collected by NASA’s Wide-field Infrared Survey Explorer (WISE) astronomers are actively hunting a class of supermassive black holes throughout the universe called blazars. The mission has revealed more than 200 blazars.Blazars are among the most energetic objects in the universe. They consist of supermassive black holes actively “feeding,” or pulling matter onto them, at the cores of giant galaxies.
The universe’s expansion is accelerating, an observation that prompted astronomers to invoke an unknown entity called dark energy to explain it, has been further confirmed by new measurements. Scientists have used cosmic magnifying glasses called gravitational lenses to observe super-bright distant galaxies, giving a measure of how quickly the universe is blowing up like a giant balloon. They found, in agreement with previous measurements, that the universe’s expansion is indeed speeding up over time.
This image, which shows NGC 4980, is composed of exposures taken in visible and infrared light by Hubble’s Advanced Camera for Surveys. The image is approximately 3.3 by 1.5 arcminutes in size.NGC 4980 is a spiral galaxy in the southern constellation of Hydra. The shape of NGC 4980 appears slightly deformed, something which is often a sign of recent tidal interactions with another galaxy. In this galaxy’s case, however, this appears not to be the case as there are no other galaxies in its immediate vicinity.
New Infrared and X-ray observations from two space telescopes strengthen the view that the galaxy may have been created by the cataclysmic collision of two older galaxies. The infrared light was captured by the European Space Agency’s Herschel Space Observatory. The X-ray observations were made by the European Space Agency’s XMM-Newton space telescope. Centaurus A is the closest giant elliptical galaxy to Earth, at a distance of around 12 million light-years.