Our local black hole is located in the region known as Sagittarius A * ("Sagittarius A *", "Sgr A *"). This compact radio source is located about 26 000 light-years away from our Solar System, and its weight is about 4.3 million times the mass of the sun.

Even at this distance, it is several hundred times closer to us than any other galaxies with active black hole at its center, making it an ideal natural laboratory for the study of the environment of these mysterious objects.

In the plane of our galaxy between its edges and the center is a huge amount of dust that hides the central part of the galaxy in the visible wavelength range. But Herschel is able to see through the dust in the far infrared range, providing researchers the ability to examine the troubled inner region of our galaxy in detail.

Herschel discovered a wide variety of simple molecules in the heart of the Milky Way, including carbon monoxide, water vapor and hydrogen cyanide. Analyzing the signatures of these molecules, astronomers are able to explore some of the fundamental properties of the interstellar gas surrounding the black hole.

"Herschel took the far infrared radiation at a distance of 1 light year from the black hole, the first time making it possible to separate the radiation at these wavelengths central cavity from the surrounding dense molecular disk," says Javier Goicoechea of ​​the Spanish Center for Astrobiology, lead author of the paper reporting the results.

The biggest surprise was the fact how hot molecular gas in the central region of the galaxy. At least some part of the temperature is about 1000 º C, which is much hotter than ordinary interstellar clouds that are usually only a few tens of degrees above -273 º C, ie absolute zero.

Although some of the heat and the hard ultraviolet radiation comes from the cluster of massive stars that are in close proximity to the Galactic Center, alone they are not enough to explain such high temperatures.

In addition to the stellar radiation, the team of Dr. Goicoechea hypothesizes that a significant contribution to the high temperatures in the region can contribute to emissions from powerful beats strongly magnetized gas. Such shock waves can be formed by collisions of gas clouds, or in the material coming from the high speed of stars and protostars.

"The observations are also consistent with the flow of hot gas moving with an acceleration towards Sgr A *, falling to the very center of the galaxy," says Dr. Goicoechea. "It may be a black hole in our galaxy cooking dinner in front of a Herschel".

Before falling into a black hole material is very very hot, which can lead to high-energy X-ray and gamma-ray bursts. Although currently Sgr A * shows no signs of such activity, this may change in the near future.

Using near-infrared observations, other astronomers noticed a single compact cloud of gas a few Earth masses, spiraling toward the black hole. Located much closer to the black hole than the tank Herschel material studied in this work, it can be absorbed by the end of this year.

Spacecraft, including the XMM-Newton, are waiting for the detection of any "high-burp" when a black hole will enjoy your holiday.

"The center of the Milky Way is a complex area, but these observations with Herschel, we took an important step forward in our understanding of the surroundings of a supermassive black hole, which will ultimately help improve our picture of the evolution of galaxies," says Göran Pilbratt, project scientist Herschel.