10 Years of XMM-Newton


XMM-Newton, the ESA’s premiere space-based X-ray observatory, will celebrate 10 years of spectacular X-ray imaging of our Universe today. On the 10th of December 1999 at 14:32 GMT, XMM-Newton was launched by the European Space Agency, and tasked with the mission of observing some of the most interesting objects in the Universe with its X-ray eyes. Many objects such as black holes and neutron stars have been studied using the telescope, because these energetic objects emit light in the X-ray spectrum.

To date, over 2000 published articles have utilized information from the XMM-Newton telescope. X-rays, a very energetic form of photons, are created in extreme celestial events, such as the disks that surround black holes and the intense magnetic fields surrounding stars. By studying the X-rays emitted by a variety of celestial objects, astronomers have been able to get detailed information about the workings of the Universe.

XMM-Newton has also been crucial to the study of galaxy clusters and supermassive black holes, and has helped to create the largest catalog of cosmic X-ray sources, with over a quarter of a million entries. It has even been enlisted in the hunt for dark matter, as one theory of the substance suggests that a decayed dark matter particle would potentially emit X-rays. Exotic objects far away aren’t the only target for the observatory, though; it’s helped astronomers detect the outer edges of the atmosphere of Mars and icy comets at the outer limits of our Solar System.

Here are just a few of the stories on Universe Today that feature observations by XMM-Newton:

To celebrate the first decade of XMM-Newton’s observations, the ESA will hold a celebration in Madrid, Spain on December 10th. Here’s a link to XMM-Newton’s image gallery, and here’s one to a list of publications utilizing the telescope’s images.

Source: Eurekalert

Milky Way’s Black Hole Gave Off a Burst 300 Years Ago

Our Milky Way’s black hole is quiet – too quiet – some astronomers might say. But according to a team of Japanese astronomers, the supermassive black hole at the heart of our galaxy might be just as active as those in other galaxies, it’s just taking a little break. Their evidence? The echoes from a massive outburst that occurred 300 years ago.

The astronomers found evidence of the outburst using ESA’s XMM-Newton space telescope, as well as NASA and Japanese X-ray satellites. And it helps solve the mystery about why the Milky Way’s black hole is so quiet. Even though it contains 4 million times the mass of our Sun, it emits a fraction of the radiation coming from other galactic black holes.

“We have wondered why the Milky Way’s black hole appears to be a slumbering giant,” says team leader Tatsuya Inui of Kyoto University in Japan. “But now we realize that the black hole was far more active in the past. Perhaps it’s just resting after a major outburst.”

The team gathered their observations from 1994 to 2005. They watched how clouds of gas near the central black hole brightened and dimmed in X-ray light as pulses of radiation swept past. These are echoes, visible long after the black hole has gone quiet again.

One large gas cloud is known as Sagittarius B2, and it’s located 300 light-years away from the central black hole. In other words, radiation reflecting off of Sagittarius B2 must have come from the black hole 300 years previously.

By watching the region for more than 10 years, the astronomers were able to watch an event wash across the cloud. Approximately 300 years ago, the black hole unleashed a flare that made it a million times brighter than it is today.

It’s hard to explain how the black hole could vary in its radiation output so greatly. It’s possible that a supernova in the region plowed gas and dust into the vicinity of the black hole. This led to a temporary feeding frenzy that awoke the black hole and produced the great flare.

Original Source: ESA News Release