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Archive for March 31, 2013

Gravitational Lensing In The Peculiar “Magatama” Galaxy


Credit: Ehime University

Credit: Ehime University

In a course of studying young galaxies at a distance of 11.6 billion light years from Earth, a team of astronomers led by Professor Yoshiaki Taniguchi (Ehime University) noticed a strangely shaped galaxy that looks like a “magatama”, an ancient, comma-shaped Japanese amulet made of stone (Figure 1). Subsequent research revealed that the magatama galaxy was actually an overlapping system of two young galaxies lying in an extremely close line of sight–an exceedingly rare occurrence among celestial objects. The small angular separation between the foreground and background galaxies gave the current team an opportunity to investigate the effect of gravitational lensing on the properties of the background galaxy. A member of the team, university student Yuya Nakahiro (Ehime University), calculated that the effect of gravitational amplification would be 20% at most. The foreground young galaxy is still forming, and the team concluded that the gravitational lensing effect from such a young galaxy does not affect the luminosity of its background galaxy.

Dr. Inoue expressed his surprise at the finding: “This result was very amazing to me, since this is the discovery of an extremely rare system.” The finding sparked Professor Taniguchi’s idea for the current research: “Soon after I knew this observational result, I became aware of the possibility that light from LAE 221724+001716 is gravitationally amplified by the foreground galaxy”.

Full Story: http://naoj.org/Pressrelease/2013/03/31/index.html