Measurements confirmed the slow warming up of galaxies

Measurements confirmed the slow warming up of galaxies
Measurements confirmed the slow warming up of galaxies
Anonim

Thanks to the increase in mass and gravity, galaxies are gradually warming up: observations have shown that today they are, on average, three times hotter than they were 10 billion years ago.

The average temperature of interstellar gas in modern galaxies reaches about two million kelvin - several times higher than that of galaxies in the young universe. This is discussed in an article by Johns Hopkins University professor Brice Ménard and his colleagues, published in The Astrophysical Journal.

The mechanism for this heating is well known: it was described by Jim Peebles, the 2019 Nobel Prize winner in physics. It is believed that over time, accumulating more and more mass, galaxies are more attracted to the surrounding gas and dust. This increases the density and the frequency of collisions of particles of the interstellar medium, which, on a large scale, leads to a slow but steady warming up. The new work confirmed these calculations.

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The increase in the temperature of galaxies between 11 billion years ago and to the present time correlates with the accumulation of mass and dark matter / © D. Nelson, Illustris Collaboration

Menard and his co-authors used observations collected over 20 years by the Planck and IAS spacecraft, as well as data from the Sloan Digital Sky survey. They compared the redshift of galaxies - a decrease in the frequency of radiation, which serves as a measure of the distance of space objects in space-time - with their temperature. As a result, the upward trend predicted by Pilbs was revealed.

According to scientists, driven by gravity, the temperature of the interstellar medium of galaxies over the past 10-11 billion years has risen almost threefold: from about 700 thousand to two million kelvin. “Our measurements are excellent confirmation of this theory,” Menard said.

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