Around a black hole at the center of the galaxy is rotating neutron star


It seems that around the supermassive black hole Sagittarius A * — a very busy place, the study of which can yield even more than expected.

Last year, about a supermassive black hole Sagittarius A * at the center of our galaxy was seen a cloud of gas G 2, weighing about three Earth. Since these objects are estimated to soon to approach to a distance, which is only two times the distance from Earth to the Sun, a recent X-ray flare from this region naturally aroused the interest of astronomers.

Is black hole has already begun to devour gas cloud, heating it and causing emit X-rays?

Magnetars can be extremely energetic neighbors: in 2004, the Earth has reached a flash of gamma rays from SGR 1806-20, will emit at 0.1 with more energy than the Sun over one hundred years of the glow. Fortunately, this magnetar is on the other side of the galaxy. A similar explosion in the 10 light-years from Earth would destroy the ozone layer, and the brightest would be equivalent to a nuclear explosion in 12 kt from a distance of 7.5 km. (Here and below illustrate NASA, Chandra.)

However, more detailed observations carried out using space-based telescope NuSTAR and "Chandra", showed no signs of destruction clouds of black hole. And on the previous calculations is the incident with the accompanying heat clouds up to a million degrees would begin only in September 2013.

Yet telescopes and astronomers have been working for nothing. April 26 NuSTAR found that X-ray signal is repeated every 3.76 seconds. And on April 29, "Chandra" localized to 0.38 light years from the black hole is very unusual object.

Taking the telescope, called a magnetar, the essence of a neutron star with an extremely strong magnetic field, reaching up to 100 billion Tesla. The majority of the properties of magnetars are close to ordinary neutron stars: a pea of their stuff weighs 100 million tons, with a diameter of 40 000-50 000 times smaller than the Sun, they are not inferior to him by weight, and so on. Yet, they differ not so rapid rotation (one revolution in 1-10 seconds) and their magnetic field in conjunction with other factors generates the periodic x-ray radiation, and even in the gamma range. Magnetars are rare, "not far" from the earth are so few. And it's not just that they do not indulge us with his birth. The existence of a strong magnetic field, they have no more than 10,000 years, which in astronomical scales very short time, and after his disappearance, gamma and X-ray emission from them disappearing.

Because at the core of our galaxy are only 13, and with the new magnetar — 14. Throughout the rest of the galaxy we know no more than a dozen such objects. The singularity of this particular instance, known as SGR J1745-2900 is that it is located near the geometric center of the Milky Way. In addition, it is so close to Sagittarius A * that powerful gravitational fields of both objects generate in the region, a number of interesting processes associated with the action of the theory of relativity.

The surrounding area of Sagittarius A *, as it turns out, is not only rich in gas clouds and ordinary stars, but magnetars.

According to general relativity, in the face of such a strong gravitational influence of the time should run a lot slower than in the area of the Earth. So as it follows a neutron star in an elliptical orbit around the black hole of several million solar masses rotation SGR J1745-2900 on its axis must accelerate to the point where it is farthest away from the black hole, and slow down where they converge on the shortest distance. The periodicity of the X-ray bursts from the magnetar is directly related to the rotation of the earth very soon telescopes will be able to check the effect of the theory of relativity with unprecedented accuracy.

However, a team of astronomers led by Kaya Mori (Kaya Mori) from the University of Toronto (Canada) warns that measure the effect of time dilation can be changed only if the orbit of rotation of the magnetar SGR J1745-2900 around Sagittarius A * is strongly elongated, and the difference between the nearest and the farthest its points is very high.

So, very close to the supermassive black hole Sagittarius A * can be rotated not only gas clouds, but also stellar objects (and the planet?) Scale. However, some astronomers have argued that within the cloud G 2 may be hiding a planet or asteroid. If so, then the vicinity of supermassive black holes are probably very busy, extremely interesting objects. A monitor them so close to the super-strong gravitational field of astronomy promise a unique perspective …

Prepared according to Nature News.

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