The Daily Galaxy --Great Discoveries Channel: Sci, Space, Tech

Radio-Waves Near Milky Way Core May Hold the Ultimate Proof of Dark Matter

 

Twenty years ago, astronomers discovered a number of enigmatic radio-emitting filaments concentrated near the center of the Milky Way Galaxy. These features initially defied explanation, but a new study of radio images of the Galactic center may point to their possible source. These mysterious "filaments" of radio-wave emission may hold the ultimate proof of the existence of dark matter, researchers have said. A new report suggests the filaments' emission arises from dark matter particles crashing into each other.

Five-Year Search leads to Discovery of the Most Distant Known Quasar Powered by a Black Hole Two Billion Times Mass of the Sun

A team of astronomers has discovered the most distant quasar to date — a development that could help further our understanding of the universe when it was still in its infancy following the Big Bang.

This brilliant and rare beacon, powered by a black hole with a mass two billion times that of the Sun, is by far the brightest object yet found from a time when the Universe was less than 800 million years old — just a fraction of its current age.

The object that has been found, named ULAS J1120+0641, is around 100 million years younger than the previously known most distant quasar. It lies at a redshift of 7.1 which corresponds to looking back in time to a Universe that was only 770 million years old, only five per cent of its current age. Prior to this discovery, the most distant quasar known has a redshift of 6.4, the equivalent of a Universe that was 870 million years old.

Hacking DNA: Scientists Generate New Organisms Not Found in Nature

An international team of researchers has now succeeded in generating a bacterium possessing a DNA in which thymine is replaced by the synthetic building block 5-chlorouracil (c), a substance toxic for other organisms. The genetic information of all living cells is stored in the DNA composed of the four canonical bases adenine (A), cytosine (C), guanine (G) and thymine (T).

Image of the Day: A Spectacular Dwarf Galaxy

This picture of the the dwarf spiral galaxy NGC 247 was taken using the Wide Field Imager (WFI) at ESO's La Silla Observatory in Chile. NGC 247 is thought to lie about 11 million light-years away in the constellation of Cetus (The Whale). It is one of the closest galaxies to the Milky Way and a member of the Sculptor Group.

A team of astronomers is currently looking into the factors that influence celestial distance markers in a study called the Araucaria Project. The team has already reported that NGC 247 is more than a million light-years closer to the Milky Way than was previously thought, bringing its distance down to just over 11 million light-years.

Apart from the main galaxy itself, this view also reveals numerous galaxies shining far beyond NGC 247. In the upper right of the picture three prominent spirals form a line and still further out, far behind them, many more galaxies can be seen, some shining right through the disc of NGC 247.

This image below of  NGC 247 was taken by Galaxy Evolution Explorer on October 13, 2003, in a single orbit exposure of 1600 seconds. The region that looks like a "hole" in the upper part of the galaxy is a location with a deficit of gas and therefore a lower star formation rate and ultraviolet brightness. Optical images of this galaxy show a bright star on the southern edge. This star is faint and red in the Galaxy Evolution Explorer ultraviolet image, revealing that it is a foreground star in our Milky Way galaxy.

The string of background galaxies to the North-East (upper left) of NGC 247 is 355 million light years from our Milky Way galaxy whereas NGC 247 is a mere 9 million light years away. The faint blue light that can be seen in the Galaxy Evolution Explorer image of the upper two of these background galaxies may indicate that they are in the process of merging together.

Credit: ESO

"The Real Earth" -- Image from Space With Gravity Field in Effect

 

The "Potsdam Gravity potato", as this image of terrestrial gravity has become known, can for the first time display gravity variations that change with time. The seasonal fluctuations of the water balance of continents or melting or growing ice masses, i.e. climate-related variables, are now included in the modeling of the gravity field.

Astronomers Discover a Neutron Star Illuminated by an X-Ray Flare

The European Space Agencies' XMM-Newton space observatory has watched a faint star flare up at X-ray wavelengths to almost 10,000 times its normal brightness. Astronomers believe the outburst was caused by the star trying to eat a giant clump of matter much larger than the neutron star and came from its enormous blue supergiant companion star.

"Eerie Voices of Saturn" - Audio Signals Differ at Its North and South Hemispheres

 

Data from NASA's Cassini spacecraft show that the variation in radio waves controlled by the planet's rotation is different in the northern and southern hemispheres. Moreover, the northern and southern rotational variations also appear to change with the Saturnian seasons, and the hemispheres have actually swapped rates.

Cygnus X-1 --A Black Hole: Harvard-Smithsonian Astronomers Prove Stephen Hawking Was Wrong

Several thousand light-years from Earth, near the "heart" of Cygnus, the swan, two stars are locked in their gravitational destiny. One star is a blue supergiant, known as HDE 226868 --about 30 times as massive as the Sun and 400,000 times brighter. The other star is 5 to 10 times the mass of the Sun, but it's extremely small. But its mass is too great to be a white dwarf or a . neutron star. The system is called Cygnus X-1, indicating it was the first source of X-rays discovered in the constellation Cygnus. Discovered by the Uhuru X-ray satellite in the early 1970s, it was also one of the first suspected black holes.

Image of the Day: The Virgo Cluster of Galaxies

Image of the Day: The Virgo Cluster of Galaxies

What mysteries lurk here! This deep image of the Virgo Cluster comprises approximately 1300 to 2000 member galaxies, forming the heart of the larger Local Supercluster, of which the Local Group is an outlying member.The image shows the diffuse light between the galaxies belonging to the cluster. North is up, east to the left. The dark spots indicate where bright foreground stars were removed from the image. The giant elliptical galaxy, Messier 87 is the largest galaxy in the picture (lower left). This giant agglomeration of galaxies is the nearest big cluster of galaxies, the largest proven structure in our intergalactic neighborhood, and the most remote cosmic objects with a physical connection to our own small group of galaxies, the Local Group, including our Milky Way galaxy.

The cluster is a mixture of spirals and elliptical galaxies, which are more centrally concentrated than the spiral galaxies. Because of the Virgo Cluster's enormous mass, its strong gravity accelerates the member galaxies to considerably high peculiar velocities, up to over 1500 km/sec, from the cluster's center of mass.

Image credit: ESO


Image credit: ESO

Weirder, Weird Weather --"La Nina, El Nino, La Nada"

Some recent news reports have attributed the nation's record snowfall, killer tornadoes, and devastating floods phenomenon to an extreme "La Niña," a band of cold water stretching across the Pacific Ocean with global repercussions for climate and weather.

"La Niña was strong in December," says NASA climatologist Bill Patzert. "But back in January it pulled a disappearing act and left us with nothing – La Nada – to constrain the jet stream. Like an unruly teenager, the jet stream took advantage of the newfound freedom--and the results were disastrous."