Thursday 06 March 2025
A group of scientists has been studying a peculiar phenomenon in the universe, where some stars and galaxies seem to be moving faster than expected. To understand this better, they used a technique called very long baseline interferometry (VLBI) to take high-resolution images of these objects.
One of the most striking examples is a quasar called PKS 1200+045. This object is so bright that it can be seen from millions of light-years away, and its radio waves are emitted in all directions like a giant beam. The scientists were surprised to find that the position of this beam is not exactly aligned with the optical position of the quasar, as determined by the Gaia spacecraft. In fact, they found that the radio beam was offset by about 40 milliarcseconds, which may seem small but is actually quite significant.
Another example is a quasar called TXS 1450+641. This object has a complex structure with two bright features that are separated by about 30 arcseconds. The scientists found that the optical position of this quasar is not exactly aligned with either of these features, which suggests that there may be more to its structure than meets the eye.
The scientists also studied a third example, called PKS 1328+254, or 3C 287. This object has been extensively studied before, but new observations revealed a previously unknown component that is much closer to the optical position of the quasar than expected. This could be evidence that this component is associated with the central engine of the quasar.
The scientists used VLBI to take high-resolution images of these objects by combining data from multiple radio telescopes around the world. They then analyzed these images to determine the position of the radio beams and compare them with the optical positions of the quasars as determined by Gaia.
The results suggest that there may be more complex structures in these quasars than previously thought, and that VLBI is a powerful tool for studying these objects in detail. The scientists hope to continue their research using VLBI to learn more about the properties of these quasars and how they are related to the universe as a whole.
By studying these quasars, scientists can gain insights into the fundamental laws of physics and the evolution of galaxies over billions of years. They may also be able to learn more about the mysterious dark matter that is thought to make up a large portion of the universe’s mass-energy budget.
Cite this article: “Unveiling Complex Quasar Structures with VLBI”, The Science Archive, 2025.
Quasars, Vlbi, Radio Telescopes, Gaia Spacecraft, Optical Position, Radio Beams, Milliarcseconds, Arcseconds, Dark Matter, Galaxy Evolution
