Researchers have depicted a monstrous galaxy near the edge of the charted Universe with unprecedented detail using the Atacama Large Millimeter/submillimeter Array (ALMA) with the assistance of a ‘natural telescope’ ie gravitational lens.
The galaxy is seen at a time when the Universe was 15% of its current age, only 2.4 billion years after Big Bang. The light has taken over twice the age of the Earth to reach us (11.4 billion years), detouring along the way around a large foreground galaxy that is comparatively close at 4 billion light-years away from our Solar System. The foreground galaxy is acting as a lens, warping SDP.81’s light and creating a near-perfect example of a phenomenon known as an Einstein Ring. The team modeled the lensing effects and corrected for them to reveal the distribution of huge stellar cradles in the monstrous galaxy shown in the image above. As a bonus, the same model indicates, for the first time, the existence of a supermassive black hole at the center of the foreground galaxy.
SDP.81 was revealed to be a monstrous galaxy forming stars at 100s – 1000s of times the rate we see in the Milky Way. This is an important step to understand the evolutionary process of starburst galaxies and supermassive black holes in galaxies. SDP.81 is an excellent example of an Einstein ring.
A correcting model shows fine structures in the ring reflect the inner structure of SDP.81. Several dust clouds 200 – 500 light-years in size are distributed within an elliptic region 5000 light-years across. The dust clouds are thought to be giant molecular clouds, the birthplaces of stars and planets. The clouds in SDP.81 have sizes similar to those found in our Milky Way and nearby galaxies (Figure 4). This is the first time astronomers have been able to reveal the inner structure of such a distant galaxy.
If the foreground galaxy has a supermassive black hole at the center, the central image becomes much fainter. Thus the brightness of the central image reflects the mass of the black hole in the foreground galaxy. The central image of SDP.81 is very faint, leading the team to conclude that the foreground galaxy holds a giant black hole over 300 million times more massive than the Sun. Â http://www.almaobservatory.org/images/newsreleases/mediacoverage/150609-theregister_co_uk-SDP_81-1.pdf
http://www.dailygalaxy.com/my_weblog/2015/10/monster-einstein-ring-galaxy-observed-at-the-end-of-the-universe-weekend-feature.html
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