Image of Galaxy M31

NASA's Swift satellite acquired the highest-resolution view of a neighboring spiral galaxy ever attained in the ultraviolet. The galaxy, known as M31 in the constellation Andromeda, is the largest and closest spiral galaxy to our own.

The image was taken by Swift's Ultraviolet Telesecope.

Image of collison between two Milky- way like Galaxies

Hubble Space Telescope has captured an image of collision between two Milky-Way like galaxies.

These two galaxies are known as NGC 2623 or Arp 243 are in the stages of emerging . The tail of NGC 2623 is richly populated with bright star clusters.

The galaxy NGC 2623 is an extensively studied galaxy and is bright in the infrared.

Motion of stars in distant galaxy

Astronomers have measured the motions of stars for the first time in a very distant galaxy, speeding around its host at twice the speed of our Sun through the Milky Way.

The speeding stars may help astronomers understand how such compact galaxies form so early in the Universe and then evolve into the galaxies we see in today's 13.7 billion year old Universe.

It will also help to see how these galaxies are formed with the help of Hubble's new Wide Field Camera 3.

A galaxy : Stephan's Quintet

Stephan's Quintet is a compact group of galaxies discovered about 130 years ago and located about 280 million light years from Earth.

Cosmic blobs and Galaxies

Cosmic blobs are immense reservoirs of hydrogen gas located in the early Universe. Black holes and star formation have been observed in cosmic blobs.

The glow of cosmic blobs in optical light had remained a mystery for the astronomers but with the help of telescopes such as Chandra X-ray Observatory,Spitzer Space Telescope and Hubble they have found that the source of power is coming from growing supermassive black holes and from newly forming stars.

Fog lifted on dark gamma-ray bursts across the universe

Gamma-ray bursts, with their ability to pierce through gas and dust to shine brightly across the universe, are revealing areas of intense star formation and stellar death where astronomers have been unable to look -- the dusty corners of otherwise dust-free galaxies.

The conclusion comes from a survey of "dark" gamma-ray bursts -- bright in gamma- and X-ray emissions, but with little or no visible light -- reported today at a meeting of the American Astronomical Society in Pasadena.

Star formation occurs in dense clouds that quickly fill with dust as the most massive stars rapidly age and explode, spewing newly created elements into the interstellar medium to seed new star formation. Hence, astronomers presume that a large amount of star formation is occurring in dust-filled galaxies, although actually measuring how much dust this process has built up in the most distant galaxies has proved extremely challenging.

Long-duration gamma-ray bursts, the most brilliant flashes of light in the universe, are thought to originate from the explosion of massive stars. These events create two pencil-like beams of light, akin to lighthouse beacons, bright enough to be seen from as far away as 13 billion light years, near the limits of the observable universe.

While most gamma-ray bursts continue to shine brightly in optical light for many hours after the gamma-ray emission subsides -- a phenomenon known as an Œafterglow' -- those with little or no detectable afterglow, dubbed "dark GRBs," have puzzled astronomers. Some have speculated that most were so far away, and thus at such high redshift, that their optical afterglow shifted out of the wavelength region that optical telescopes can detect

On the edge of a hungry black hole

Gas and dust equal to the mass of two Earths are being gobbled up every hour by a hungry black hole in a distant galaxy, according to a space telescope probing the Universe in X-rays that has peered closer to a black hole than ever before.

The European Space Agency’s orbiting XMM-Newton observatory studied the black hole in the core of an active galaxy known only as 1H0707-495. This particular galaxy is described as Seyfert 1 galaxy, which typically have bright centres emitting a broad range of hydrogen emission but narrow emission lines of heavier elements such as iron. Four out of five Seyfert galaxies are barred spirals. The bars funnel large amounts of gas into the core, which then feeds into a spiralling disc around the supermassive black hole located in the centre of the galaxy.

As the gas spins around the black hole, it heats up, producing X-rays that then illuminate clumps of matter in the disc. To get a better grasp of the size and distribution of material in this disc, astronomers used XMM-Newton to search for X-rays emitted by iron atoms. They chose iron because it has a distinctive signature that is affected by the spin of the black hole, the velocity at which the iron atoms are orbiting around the black hole, and the energy required to escape the black hole’s gravity. As such, they can tell us a lot about the characteristics of the black hole.

Most detailed map of nearby Universe completed

Researchers from Australia, the UK and the USA have just completed the most detailed survey of galaxies in the nearby Universe, which will reveal not only where the galaxies are but also where they are heading, how fast, and why.

Galaxies are tugged around by each other's gravity. By measuring the galaxies' movements, the researchers can map the gravitational forces at work in the local Universe, and so show how matter, seen and unseen, is distributed.

The survey shows strings and clusters of nearby galaxies on large scales in unprecedented detail, and has revealed more than 500 voids’ apparently empty areas of space with no galaxies.