High Contrast Imaging Reveals Unknown Structure in Galaxy
Artist’s impression of a giant galaxy with a high-energy jet. Credit: ALMA (ESO/NAOJ/NRAO)
Astronomers have just discovered an unknown structure in a galaxy that had been hidden in the “shadows.” They accomplished this by extending the dynamic range of the Atacama Large Millimeter/submillimeter Array (
As a result of achieving high imaging dynamic range, a team of astronomers in Japan has discovered for the first time a faint radio emission covering a giant galaxy with an energetic black hole at its center, which swallows its surrounding material, giving off enormous radiation. Contrary to its bland name, 3C273 is the first quasar ever discovered, the brightest, and the best studied. It is one of the most frequently observed sources with telescopes because it can be used as a standard of position in the sky: in other words, 3C273 is a radio lighthouse.
Bright Quasar 3C 273
The first quasar ever to be identified, 3C 273 was discovered by astronomer Allan Sandage in the early 1960s. Despite being located about 2.4 billion light years away in a giant elliptical galaxy in the constellation of Virgo, it is the optically brightest quasar in the sky from Earth.
When you see a car’s headlight, the dazzling brightness makes it challenging to see the darker surroundings. The same thing happens to telescopes when you observe bright objects. Dynamic range is the contrast between the most brilliant and darkest tones in an image. You need a high dynamic range to reveal both the bright and dark parts in a telescope’s single shot. ALMA can regularly attain imaging…
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