Astronomy in the Atacama
Chile’s Very Large Telescope detects rare ‘green bean galaxies’
Scientists in Northern Chile’s astronomical observatories discover what are considered by many to be the rarest objects in the Universe.
Friday, January 18, 2013
Green bean galaxies as captured by European Southern Observatory’s (ESO) Very Large Telescope (VLT). Photo courtesy of ESO.
Humorously nicknamed ‘green bean galaxies’, these eerily-hued, green galaxies are one of the newest discoveries to emerge from astronomical observatories in Chile’s Atacama Desert.
This December, combined findings from the European Southern Observatory’s (ESO) Very Large Telescope (VLT), the Gemini South telescope, and the Canada-France-Hawaii Telescope (CFHT), confirmed the existence of what ESO called some of “the rarest objects in the Universe.”
Often galaxies center around tremendous black holes that cause the gases in the immediate vicinity to glow. This glow generally occupies up to ten percent of the entire galaxy. In the case of green bean galaxies however, the entire galaxy is radiant - not just the locations nearest the center. The galaxies observed in December mark the largest radiant regions ever found.
Astronomer Mischa Schirmer of the Gemini Observatory originally observed this bizarre phenomenon from the Gemini South Telescope and immediately applied for permission to carry on observation at ESO’s Very Large Telescope in Chile’s Atacama Desert.
“ESO granted me special observing time at very short notice and just a few days after I submitted my proposal, this bizarre object was observed using the VLT,” Schirmer said in an online statement. “Ten minutes after the data were taken in Chile, I had them on my computer in Germany. I soon refocused my research activities entirely as it became apparent that I had come across something really new.”
After discovering the original green bean galaxy, Schirmer and his team surveyed nearly a billion other galaxies and found 16 other examples. So rare are these green bean galaxies that astronomers estimate that one exists for every 1.3 billion-light years cubed.
Astronomers named the original green bean galaxy J224024.1−092748 (or J2240). J2240 is located in the Aquarius constellation around 3.7 billion light years away from Earth.
The ramifications of such exciting finds are immense. Schirmer described the potential of these green bean galaxies as a way to stick “a medical thermometer into a galaxy far, far away.”
“Usually, these regions are neither very large nor very bright, and can only be seen well in nearby galaxies,” Schirmer explained. “However, in these newly discovered galaxies they are so huge and bright that they can be observed in great detail, despite their large distances.”
Due to its almost non-existent humidity and clear skies, the Atacama is the planet’s premier location for astronomy. Chile is home to almost half the world’s telescope infrastructure, and this is set to increase to over two thirds by 2018.