An odd arc of light has led to one of the newest cosmology discoveries to come from the Hubble telescope: a massive, ancient galaxy cluster.
The arc of light comes from a fairly normal galaxy, but it’s been warped in a process called gravitational lensing. Lensing occurs when an object is massive enough to distort the light rays traveling near it.
In this case, astronomers observed the light coming from behind a massive galaxy cluster more than 10 billion light-years away, and between the lensed galaxy and us. Lensing has never been seen that was caused by such a distant cluster. The researchers report their findings in the Astrophysical Journal. [Anthony H. Gonzalez et al., "IDCS J1426.5+3508: Cosmological implications of a massive, strong lensing cluster at Z = 1.75"]
In general, galaxy clusters are smaller the older they are, so finding such a massive galaxy cluster was improbable to begin with. This one is five to 10 times larger than other clusters of similar vintage, dating back to when the universe was only a quarter of its present age.
Further study may determine if concentrations of galaxies of this age and brightness are greater than previously thought, or whether this finding was just lucky. In other words, future research will shed more light.
[The above text is a transcript of this podcast.]