Magnetar behaves strangely near a supermassive black hole


    Photo: NASA / CXC / INAF / F.Coti Zelati et al

    In 2013, astronomers announced that they had discovered the magnetar incredibly close to a supermassive black hole in the center of the Milky Way (it is believed that supermassive black holes exist in the center of many galaxies). The star was discovered thanks to several telescopes in orbit, including the Chandra Space X-ray Observatory.

    Magnetar is a destroyed (neutron) star with an exceptionally strong magnetic field (up to 10 11 T).

    The SGR 1745-2900 magnetar seen in 2013 is only 0.3 light years from the edge of a black hole, which has a mass of 4 million solar masses in the center of our galaxy. Today it is the neutron star closest to a supermassive black hole, which scientists have been able to detect. Perhaps it is even under the gravitational influence of a black hole, that is, in curved space-time.

    Since its discovery two years ago, when it received the first wave of radiation from a magnetar, astronomers have been closely observing it using the Chandra Observatory and the XMM-Newton X-ray telescope from the European Space Agency.

    The illustration above shows the area near the black hole obtained by the Chandra X-ray. Red, green and blue color correspond to low, medium and strong x-rays, respectively. Separate inserts show a fragment of the photograph where the magnetar appeared. On the left is a combined photo for 2005-2008, it is not visible there. On the right is the 2013 shot when the magnetar radiation pulse was received, which led to the detection.


    Fast rotating neutron star generates a powerful magnetic field

    Two years of observation of the object showed that X-ray radiation from SGR 1745-2900 decreases faster than other known magnetars, and its surface is hotter than expected.

    A group of scientists who are researching SGR 1745-2900 published a scientific paper., which cites the results of the study and puts forward versions, with which unexpected properties of the magnetar may be associated.

    One version is that the surface of the magnetar could undergo powerful “star quakes” (similar to earthquakes). When a neutron star is formed, a thick crust may form on its surface. At times, this crust may crack like the crust during earthquakes.Star

    quakes explain the changes in brightness and the rapid cooling of many magnetars, but they are not able to explain the slow drop in X-ray emission level SGR 1745-2900, scientists write, as well as the abnormally high temperature of the crust. With a star quake, everything should happen faster, but here it is too slow.

    Researchers suggest that bombardment of the magnetar surface by charged particles stuck in tangled magnetic field nodes above the magnetar surface can provide additional surface heating and explain the slow decrease in x-ray radiation.

    Scientists do not believe that the properties of a magnetar are caused by its proximity to a supermassive black hole, since the distance of 0.3 light years is still too large for stable interaction through magnetic fields or gravity.

    Observation of SGR 1745-2900 will continue to collect new data and explain its unusual behavior.

    Based on materials from the Chandra Space X-ray Observatory website

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