Located in Chile’s Atacama Desert, the Atacama Large Millimeter/submillimeter Array (ALMA) has recently gone online and astronomers are beginning to realize its powerful potential.
As part of the ALMA Long Baseline Campaign that was carried out at the end of 2014 when the observatory’s antennae were at their widest separation of 15 kilometers (9.3 miles), this ancient galaxy was spotted. Warped by a massive foreground galaxy, the light from the ancient galaxy called SDP.81 (that was forming when the universe was 15 percent the age it is now) has been bent around the warped spacetime.
Made famous in Hubble observations, gravitational lenses are fairly common, where distant sources of light become warped around massive objects such as galactic clusters. Bright arcs are often seen and, if the configuration is just right, these arcs turn into circles creating stunning Einstein rings, as this ALMA example shows.
Most recently, Hubble’s powerful optics have been supplemented by these natural lenses, helping us see even further into the cosmos — a survey project called “Frontier Fields.” In many cases, the arcs of distant galactic light have been de-warped and pieced back together so we can gain a unique look at galaxies that would otherwise be out of view from even the most powerful space telescope.
But this near-perfect ring wasn’t captured by Hubble, ALMA has boosted the resolution of this ring, revealing never-before seen detail in this young star-forming galaxy.
The beauty of long-baseline interferometers (such as ALMA) is that individual antennae can be spaced far apart, simulating a collecting area of that baseline distance. In other words, ALMA is simulating a collecting dish 15 kilometers wide, boosting our observational potential, overshadowing the biggest space-based telescope mirror.
Read more at Discovery News
No comments:
Post a Comment