"A team of astronomers recently found a new [Einstein cross] using the Dark Energy Spectroscopic Instrument mounted on a telescope at Kitt Peak National Observatory... The lens system, called DESI-253.2534+26.8843, is actually a massive foreground elliptical galaxy surrounded by four blue images of a background galaxy. Team leader Aleksandar Cikota of NOIRLab, pointed out what those images that form a perfect Einstein Cross pattern reveal. “The four images that display consistent spectral features tell the astronomers that the source is a single galaxy, which allowed them to confirm the lens system,” he said. “The cross pattern tells them about the mass distribution of the lens galaxy. Elongated mass distributions result in Einstein crosses, and a spherical mass distribution would result in an Einstein ring.This latest Einstein Cross has some interesting statistics. The main galaxy doing the lensing lies about 5.998 billion light-years away. The distant galaxy that it’s lensing is more than 11.179 billion light-years away. Thus, the foreground lensing galaxy is giving an amazing look at a galaxy in the early Universe...When a massive galaxy sits directly “in front of” a more distant background object (such as a galaxy or a quasar) the distribution of matter around that galaxy and its gravitational effect can “bend” the light from the object as it passes by. That results in lensed images (or a ring)..."
"Hubble image of a luminous red galaxy (LRG) gravitationally distorting the light from a much more distant blue galaxy, a technique known as gravitational lensing. The shape of the galaxy doing the lensing created an almost circular image. An oblong galaxy would create an Einstein Ring effect. Credit: NASA/ESA/STScI"
Text, images, and post title via Universe Today, where there is more information.
No comments:
Post a Comment