Thursday, September 18, 2014

Black holes in the world anymore – BBC

supermassive black holes in the universe may be greater than what is considered: it turned out that they do not live only in large galaxies like our own Milky Way, but also in children. One such “flat” for the black hole – galaxy M60-UCD1 – find an international team of astronomers, which included a scientist from Russia.

about his discovery, astronomers told in the journal Nature .

Ultra-compact dwarf galaxies are among the most dense stellar systems in the universe. Now they know about a hundred. They belong to the galaxy M60-UCD1, one of the largest galaxies of this type, which is from the Earth at a distance of 54 million light-years away and is a satellite galaxy – M60.

A team of astronomers interested in this mini-galaxy still in Last year, it emerged that she has an abnormally high density and in addition has an internal source of gamma radiation. This year, they analyzed their observations at the telescope Geminy North, located on the Hawaiian Islands, and snapshots Space Telescope “Hubble».

In this paper, participated Russian researcher – Leading Researcher Sternberg Astronomical Institute of the PK Moscow State University Sternberg Chilingarian Igor, who also works in the Harvard-Smithsonian Center for Astrophysics.

According Chilingarian “the Newspaper”, in this work he carried out an independent analysis of the data. “As the journal Nature has a mixed reputation in the astronomical community, I wanted to double-check the result, which is published by our group, and conducted an analysis of the same data with other models, namely the theoretical spectra of stellar atmospheres. This analysis has fully confirmed what had been done with the help of spectra of real stars, obtained 18 years ago ».

According to the Russian scientist, the article was written by” incredibly fast “: work was sent to the journal Nature, despite the fact that it is based on observations obtained at the end of May.

The authors found that the stars in the dwarf galaxies move at speeds of about 100 km / sec, and this for the simple star clusters too quickly and can be explained only by the presence of a large black hole.

The scientists also calculated its mass: 21 million Suns, five times more than the mass of the central black hole in our galaxy. And if the latter is only one-hundredth of a percent of the mass of the entire galaxy, the M60-UCD1, with its total weight to 140 million solar masses, the mass of the black hole takes more than 15%.

In such small galaxies, black holes of this magnitude can not be born in theory.

Scientists believe that the M60-UCD1 is a remnant of the once very large elliptical galaxy, composed probably about 10 billion stars , this galaxy is about 10 billion years ago, met with an even larger M60, which fleeced her, tore off her gravity of his most stellar material.

And most of all, even those remnants of its former greatness, which surround the orphaned supermassive black hole, also doomed. As time passes, and M60-UCD1 will be completely absorbed by its powerful neighbor, and the black hole will merge with its black hole, which is more than a thousand times more massive than our own. When this happens – is unknown, as unknown trajectory around the dwarf galaxy M60.

But it seems that in astronomical terms come soon:

M60-UCD1 orbits, which is separated from the center of M60 only 22 thousand. light years, and it’s even closer than the distance separating the Sun from the center of the Milky Way.

According to lead author of the article Enila Seth of the University of Utah, like supermassive black holes may be inside of other ultra-compact dwarf galaxies, which means that they are much larger than previously thought.

Just ” living conditions, “they are much worse.

« The result is a bright and interesting, and the main speculation is that if all the ultra-bright dwarf galaxies contain such black holes, the total number of supermassive black holes may be underestimated almost doubled, “- said Igor Chilingarian.

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