X-ray observations of about 1,600 quasars, super-heavy black holes galaxies that are active in their hearts, indicate that dark energy, the mysterious force that accelerates the expansion of the universe, may not be a cosmological constant. Instead, it could become sturdy throughout cosmic time.
Dark energy was explored about Twenty Years ago by observations of type 1a supernovae, blast in binary systems that create the same levels of brightness. By comparing the apparent brightness of a Type 1a supernova with identified absolute brightness, astronomers can use them as standard sails to compute the distance to the host system.
After accurately calculating the velocities and distances of about four dozen Type 1a supernovae, the researchers concluded that the universe’s expansion began to accelerate about 6 billion years ago. The dark energy that fueled this acceleration was considered a constant and did not control the collective gravity of normal matter and dark matter until the universe developed and spilled enough after the big bang.
Distances based on measurements of type 1 supernovae illustrate the effects of dark energy in the last 9 billion years. The observations by new X-ray, led by Elisabeta Lusso Durham University, UK and Guido Risaliti of the Università di Firenze, Italy, ease the limit to about a billion years after the Big Bang. And these observations indicate that dark energy may not be as reliable.
In quasars it sends the disk with the material around a super-black hole and oscillates ultraviolet rays, from which they store some of the electrons in the gas clouds above and below the disk, making the X-rays sufficiently heated so to generate a known correlation between the UV and X-rays. Risaliti and Lusso could use quasars as classical candles, showing the effects of dark energy until about a billion years after the big bang.