A Violent Wind Blown from the Heart of a Galaxy Tells the Tale of a Merger

The Subaru Telescope has successfully revealed the detailed structure of a massive ionized gas outflow streaming from the starburst galaxy NGC 6240. Located in the constellation Ophiuchus, NGC 6240 lies about 350 million light-years away. The ionized gas astronomers observed extends across 300,000 light-years and is carried out of the galaxy by a powerful superwind. The light collecting power and high spatial resolution of the Subaru Telescope made it possible to study, for the first time, the complex structure of one of the largest known superwinds. The detailed data analysis also revealed that NGC 6240 experienced violent starbursts at least three times in the past since the galaxy merger process took place.