Star Factory In The Early Universe Challenges Galaxy Evolution Theory

A team including Mat Page (UCL Space and Climate Physics) has discovered an extremely distant galaxy making stars more than 2000 times faster than our own Milky Way. Seen at a time when the Universe was less than a billion years old, its mere existence challenges our theories of galaxy evolution. The observations were carried out using the European Space Agency’s Herschel Space Observatory.

The galaxy, known as HFLS3, appears as little more than a faint, red smudge in images from the Herschel Multi-tiered Extragalactic Survey (HerMES). Yet appearances can be deceiving: this small smudge is actually a star-building factory, furiously transforming gas and dust into new stars.

Our own Milky Way makes stars at a rate equivalent to one solar mass per year, but HFLS3 is seen to be churning out new stars at more than two thousand times more rapidly. This is one of the highest star formation rates ever seen in any galaxy.

Full Story: https://www.ucl.ac.uk/maps-faculty/maps-news-publication/maps1306

Hubble Observes The Hidden Depths Of Messier 77

Image credit: NASA, ESA & A. van der Hoeven

Messier 77 is a galaxy in the constellation of Cetus, some 45 million light-years away from us. Also known as NGC 1068, it is one of the most famous and well-studied galaxies. It is a real star among galaxies, with more papers written about it than many other galaxies put together!

Despite its current fame and striking swirling appearance, the galaxy has been a victim of mistaken identity a couple of times; when it was initially discovered in 1780, the distinction between gas clouds and galaxies was not known, causing finder Pierre Méchain to miss its true nature and label it as a nebula. It was misclassified again when it was subsequently listed in the Messier Catalogue as a star cluster.

Now, however, it is firmly categorised as a barred spiral galaxy, with loosely wound arms and a relatively small central bulge. It is the closest and brightest example of a particular class of galaxies known as Seyfert galaxies — galaxies that are full of hot, highly ionised gas that glows brightly, emitting intense radiation.

Full Story and Image: http://www.spacetelescope.org/news/heic1305/

CSI: Milky Way

Artist’s illustration. Credit: Julie Turner, Vanderbilt University

These days the core of the Milky Way galaxy is a pretty tame place…cosmically speaking. The galactic black hole at the centre is a sleeping giant. Existing stars are peacefully circling. Although conditions are favourable, there doesn’t even seem to be much new star formation going on. But there is growing evidence that several million years ago the galactic centre was the site of all manner of celestial fireworks. A pair of assistant professors – Kelly Holley-Bockelmann at Vanderbilt and Tamara Bogdanović at Georgia Institute of Technology – has come up with an explanation that fits these “forensic” clues.

Writing in the March 6 issue of the Oxford University Press journal Monthly Notices of the Royal Astronomical Society, the astronomers describe how a single event – a violent collision and merger between the galactic black hole and an intermediate-sized black hole in one of the small “satellite galaxies” that circle the Milky Way – could have produced the features that point to a more violent past for the galactic core.

“Tamara and I had just attended an astronomy conference in Aspen, Colorado, where several of these new observations were announced,” said Holley-Bockelmann. “It was January 2010 and a snow storm had closed the airport. We decided to rent a car to drive to Denver. As we drove through the storm, we pieced together the clues from the conference and realized that a single catastrophic event – the collision between two black holes about 10 million years ago – could explain all the new evidence.”

Full Story: http://www.ras.org.uk/news-and-press/224-news-2013/2227-csi-milky-way
Also: http://news.vanderbilt.edu/2013/03/csi-milky-way/

Gravitational Telescope Creates Space Invader Mirage

Credit: NASA & ESA. Acknowledgement: N. Rose

The NASA/ESA Hubble Space Telescope is one of the most powerful available to astronomers, but sometimes it too needs a helping hand. This comes in the form of Einstein’s general theory of relativity, which makes galaxy clusters act as natural lenses, amplifying the light coming from very distant galaxies.

Abell 68, pictured here in infrared light, is one of these galaxy clusters, and it greatly boosts the power of Hubble, extending the telescope’s ability to observe distant and faint objects.

The effect of this huge concentration of matter is to deform the fabric of spacetime, which in turn distorts the path that light takes when it travels through the cluster. For galaxies that are even further away than the cluster — which is already at the impressive distance of two billion light-years — and which are aligned just right, the effect is to turn galaxies that might otherwise be invisible into ones that can be observed with relative ease.

Although the resulting images projected to us of these distant galaxies are typically heavily deformed, this process, called gravitational lensing, is a hugely valuable tool in cosmology, the branch of astronomy which deals with the origins and evolution of the Universe.

Full Story: http://www.spacetelescope.org/news/heic1304/
Also: http://hubblesite.org/newscenter/archive/releases/2013/09/image/a/

Supermassive Black Hole Spins Super-Fast

Artist’s conception. Image credit: NASA/JPL-Caltech

Imagine a sphere more than 2 million miles across – eight times the distance from Earth to the Moon – spinning so fast that its surface is traveling at nearly the speed of light. Such an object exists: the supermassive black hole at the center of the spiral galaxy NGC 1365.

Astronomers measured its jaw-dropping spin rate using new data from the Nuclear Spectroscopic Telescope Array, or NuSTAR, and the European Space Agency’s XMM-Newton X-ray satellites.

Astronomers measured its jaw-dropping spin rate using new data from the Nuclear Spectroscopic Telescope Array, or NuSTAR, and the European Space Agency’s XMM-Newton X-ray satellites.

Astronomers want to know the black hole’s spin for several reasons. The first is physical – only two numbers define a black hole: mass and spin. By learning those two numbers, you learn everything there is to know about the black hole.

Most importantly, the black hole’s spin gives clues to its past and by extension the evolution of its host galaxy. “The black hole’s spin is a memory, a record, of the past history of the galaxy as a whole,” explained Risaliti.

Full Story: http://www.cfa.harvard.edu/news/2013/pr201307.html
Also: http://www.jpl.nasa.gov/news/news.php?release=2013-075
Also: https://www.llnl.gov/news/newsreleases/2013/Feb/NR-13-02-08.html

A Spiral Galaxy With A Secret

Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany

Despite its appearance, which looks much like countless other galaxies, Messier 106 hides a number of secrets. Thanks to this image, which combines data from Hubble with observations by amateur astronomers Robert Gendler and Jay GaBany, they are revealed as never before.

At its heart, as in most spiral galaxies, is a supermassive black hole, but this one is particularly active. Unlike the black hole at the centre of the Milky Way, which pulls in wisps of gas only occasionally, Messier 106’s black hole is actively gobbling up material. As the gas spirals towards the black hole, it heats up and emits powerful radiation. Part of the emission from the centre of Messier 106 is produced by a process that is somewhat similar to that in a laser – although here the process produces bright microwave radiation.

As well as this microwave emission from Messier 106’s heart, the galaxy has another startling feature – instead of two spiral arms, it appears to have four. Although the second pair of arms can be seen in visible light images as ghostly wisps of gas, as in this image, they are even more prominent in observations made outside of the visible spectrum, such as those using X-ray or radio waves.

Full Story: http://www.spacetelescope.org/news/heic1302/
Also: http://heritage.stsci.edu/2013/06/caption.html

Shedding Light On The Power Of M 82′s Superwinds

An international team of astronomers, led by Dr. Kazuya Matsubayshi (Kyoto University), has discovered that outflows of gas from starburst galaxy M 82 collide with a “cap” of gas clouds 40,000 light years away from the galactic disk. Shockwaves from M 82′s central starburst region are the most likely source of the bright clouds within the cap. The large light-gathering power of Subaru Telescope’s 8.2-m mirror and its ability to produce highly detailed images enabled the researchers to make these findings, which provide important clues about the wind’s power.

The central regions of starburst galaxies are sites of immense star formation. They give birth to thousands of massive stars, which are dozens of times heavier than the Sun and then explode as supernovae when they die. Many supernovae explosions heat the gas around them to temperatures of more than a million degrees, and this hot gas flows out from the galaxy as galactic wind. These winds are so powerful that they may play an important role in the evolution of galaxies and the inter-galactic medium.

Full Story: http://www.naoj.org/Pressrelease/2012/12/26/index.html

NASA’s GALEX Reveals The Largest-Known Spiral Galaxy

Spiral Galaxy NGC 6872. Credit: NASA’s Goddard Space Flight Center/ESO/JPL-Caltech/DSS

The spectacular barred spiral galaxy NGC 6872 has ranked among the biggest stellar systems for decades. Now a team of astronomers from the United States, Chile and Brazil has crowned it the largest-known spiral, based on archival data from NASA’s Galaxy Evolution Explorer (GALEX) mission, which has since been loaned to the California Institute of Technology, Pasadena, Calif.

Measuring tip-to-tip across its two outsized spiral arms, NGC 6872 spans more than 522,000 light-years, making it more than five times the size of our Milky Way galaxy.

“Without GALEX’s ability to detect the ultraviolet light of the youngest, hottest stars, we would never have recognized the full extent of this intriguing system,” said lead scientist Rafael Eufrasio, a research assistant at NASA’s Goddard Space Flight Center in Greenbelt, Md., and a doctoral student at Catholic University of America in Washington. He presented the findings Thursday at the American Astronomical Society meeting in Long Beach, Calif.

Full Story: http://www.nasa.gov/mission_pages/galex/galex20130110.html

First “Bone” Of The Milky Way Identified

Credit: NASA/JPL/SSC

Our Milky Way is a spiral galaxy – a pinwheel-shaped collection of stars, gas and dust. It has a central bar and two major spiral arms that wrap around its disk. Since we view the Milky Way from the inside, its exact structure is difficult to determine.

Astronomers have identified a new structure in the Milky Way: a long tendril of dust and gas that they are calling a “bone.”

“This is the first time we’ve seen such a delicate piece of the galactic skeleton,” says lead author Alyssa Goodman of the Harvard-Smithsonian Center for Astrophysics (CfA). Goodman presented the discovery today in a press conference at a meeting of the American Astronomical Society in Long Beach, Calif.

Full Story: http://www.cfa.harvard.edu/news/2013/pr201302.html

Massive Outburst In Neighbor Galaxy Surprises Astronomers

The surprising discovery of a massive outburst in a neighboring galaxy is giving astronomers a tantalizing look at what likely is a powerful belch by a gorging black hole at the galaxy’s center. The scientists were conducting a long-term study of molecules in galaxies, when one of the galaxies showed a dramatic change.

The scientists were using the National Science Foundation’s (NSF) 305-meter William E. Gordon Telescope at Arecibo for their study when they discovered the outburst in NGC 660, a spiral galaxy 44 million light-years distant in the constellation Pisces. The outburst was ten times brighter than the largest supernova, or exploding star. They reported their findings at the American Astronomical Society’s meeting in Long Beach, California.

After detecting the outburst, the team continued to observe NGC 660 with the Arecibo Telescope, and also sought to determine the cause of the outburst using an international network of telescopes to make a detailed image of the galaxy.

Full Story: http://www.nrao.edu/pr/2013/ngc660/