These are heavy bodies on their way from a distant source, deflecting and amplifying the object's light, thus allowing us to glimpse the edges of the known universe
Dr. David Issachari
The universe, as seen by modern astrophysics, is so large and vast that one might despair of studying its secrets and mysteries. However, at the same time, it turns out that the large and diverse universe also provides us with natural "means of observation" that we could not have imagined existed and thus continue to explore its depths despite their great distance.
One of these impressive measures is "gravitational lensing". These are pale galaxies, which actually act as lenses and concentrate the light, the energy coming from bodies located at the edges of the universe, such as quasars, without which we could not learn much about them. The lenses themselves work according to Einstein's theory of general relativity and are also a spectacular confirmation of this theory.
At the edges of the universe we are only able to see quasars, since other bodies, such as ordinary galaxies, will be very dark by the time it reaches us. On the other hand, it is a kind of tautology, if we see something at the ends of the universe (we determine that it is at such a distance according to the "redshift"), then it is clear that when you multiply the distance squared in order to correct the intensity of the energy flux, it is clear that we will get a very large number. From here there is a fear of the existence of a conceptual vicious circle that needs to be warned against.
In any case, such an energetic body (which produces an energy flux equal to a trillion suns), can apparently operate, if the "furnace" that "extracts" it is built in a supermassive black hole that swallows an entire galaxy.
In such conditions, very energetic X-rays are also produced. Monitoring of these X-rays using the Chandra observation satellite has recently made it possible to accurately determine the distances of the quasars, and thus the Hubble constant, and thus the size and fate of the universe in a more precise way.
These findings have recently been reported
George Chartas, at The Pennsylvania State
University (Penn State) and Marshall W. Bautz, at the Massachusetts Institute of Technology (MIT) Center for Space Research
At a conference held today (today!) in Honolulu on the topic of high-energy astrophysics.
They used "ghost figures" (mirages), of a quasar as it is obtained after the passage of the radiation near the lens which is not well focused of course. The quasar they followed was called quasar RXJ 0911.4+0551. The idea was to follow the changes in its intensity in the different positions of the mirages, due to the different optical ways of their passage. The "wave" of the intensity change lasted 2000 seconds. This waveguide provides information to calculate the distance to the splitting "lens", from which the distance to the source can be calculated.
This promising method was proposed by Sjur Refsdal in 1964. Measurements at conventional energies, visible light and radio,
They suffered from a limitation of low power, therefore many measurements were required to discover and measure the difference wave which took many months and even years.
Now, with the measurements using X-rays, real variability is achieved within a few hours. This is how they hope to measure the distance of the quasar exactly, its speed is measured directly according to the redshift, and from this they hope, while observing 10 such quasars, to get the "Hubble constant" with great accuracy.
The reported measurement was performed on November 2, 1999 by an advanced CCD spectrometer ACIS.
This is also how science progresses, towards deciphering the secrets of the universe,
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