First Look At New, Rarely Observed Hoag-Type Galaxy Located 359 Million Light-Years From Earth
Scientists have discovered a galaxy unlike any other spotted before, the strange formation is roughly 359 light-years away from Earth. Named PGC 1000714, new research describes its elliptical core surrounded by two circular rings, marking it as a Hoag-type galaxy.
The research, published Nov. 30, in the Oxford journal Monthly Notices of the Royal Astronomical Society, was conducted by researchers at the University of Minnesota Duluth and the North Carolina Museum of Natural Sciences.
PGC 1000714, A Mysterious Galaxy
As part of their analysis, the scientists gathered multi-waveband images of the newly found galaxy. This hasn't been an easy task since the formation is only visible from the Southern Hemisphere using a large diameter telescope. The site that the researchers chose for their observations was located in the Chilean mountains. The researchers' plan was to identify the ages of the two main compounds of the galaxy — its outer blue ring and the central body.
First, the observations revealed a blue (and young) outer ring, which is no more than 0.13 billion years old and surrounding a significantly older red core of about 5.5 billion years. However, to their surprise, there was a second inner ring that they hadn't observed the first time.
In order to examine the second ring, the researchers subtracted the core with the multi-waveband imaging which allowed them to properly observe and analyze the particularities of this obscure formation.
"We've observed galaxies with a blue ring around a central red body before, the most well-known of these is Hoag's object. However, the unique feature of this galaxy is what appears to be an older diffuse red inner ring," noted Patrick Treuthardt, co-author of the study, from the North Carolina Museum of Natural Sciences.
What we perceive as galaxy rings, which are a really rare phenomenon as it is and accounts for no more than 0.1 percent of the entire number of galaxies we have come across, are actually areas where stars were formed as a result of gas collision.
Additionally, the fact that the two rings of the galaxy are differently colored implies that the galaxy went through a two-step formation process, which took place at a distance from one another, should they be put in a time frame. Through the tools they have at their disposal to conduct the analysis, scientists claim that it's close to impossible to fully understand the formation process of the PGC 1000714 galaxy.
New Material In Understanding Hoag-Type Galaxies
The research represents a pillar in the attempt to gather a various number of snapshots from different angles of other similarly formed galaxies, which will soon allow scientists to fully comprehend the mechanisms of the formation process and the evolution that followed.
What remains clear is that galaxy shapes can be dictated by both internal and external environmental interactions, and the research suggests that the outer ring of this newly found galaxy could, in fact, incorporate fractions of what once might have been a gas-rich dwarf galaxy orbiting near PGC 1000714.