Radiointerferometreissä

Radiointerferometreissä is a Finnish term referring to radio interferometers. A radio interferometer is an astronomical instrument consisting of multiple radio telescopes that are used together as a single, larger resolving aperture. By combining the signals from these separate telescopes, which are separated by a significant distance (the baseline), astronomers can achieve a much higher angular resolution than would be possible with a single telescope. This increased resolution allows for the detailed study of faint or distant radio sources, such as galaxies, quasars, and pulsars.

The fundamental principle behind radio interferometry is constructive and destructive interference of electromagnetic waves. When radio waves from a celestial object reach the individual telescopes, they are recorded. The time difference between when a signal arrives at each telescope depends on the object's position in the sky and the separation between the telescopes. By analyzing these time differences and the phase of the incoming waves, the instrument can reconstruct an image of the radio source with a resolution proportional to the wavelength of the observed radiation divided by the baseline length.

Common types of radio interferometers include arrays of fixed antennas, such as the Very Large Array (VLA) in New Mexico, and arrays that utilize Earth rotation synthesis, where the Earth's movement effectively changes the baselines over time. Very Long Baseline Interferometry (VLBI) connects telescopes across vast distances, even continents, to achieve the highest resolutions. These instruments are crucial for understanding the structure and dynamics of cosmic phenomena that are invisible or poorly resolved by optical telescopes.