Question: As per definition, Gravitational lensing refers to bending of light rays from a distant source around a massive object (Galaxy cluster) which tends to magnify the background light source. If visible light rays bend around those massive objects then X-rays, Gamma rays, UV and IR rays which forms a part of electromagnetic spectrum must also bend around those massive objects. If true, Are there any initiative to detect those distant lensed invisible objects using the space observatories(Chandra X-ray, Spitzer IR etc.)? – Vinod
Answer: Yes. In fact, just a few days ago there was a press release announcing the detection of the spin of a black hole using the gravitationally-lensed x-ray emission from a black hole in a distant quasar. Gravitational lensing has also been used to study galaxies using the Spitzer Space Telescope. In fact, as their is no wavelength dependence to the gravitational lens effect it is possible to study gravitationally-lensed objects at all wavelengths.