"..This high ratio means that the galaxy created all its stars in a cosmic eye-blink, before any iron-producing white dwarfs exploded. The growth spurt lasted only 100 to 500 million years.
“This galaxy just went off like crazy, and it had a huge vigorous star-forming period,” Kriek says. Then, for unknown reasons, COSMOS 11494 suddenly quit making new stars.
The galaxy’s stellar mass is five times the Milky Way’s, or about 320 billion solar masses. Divide that number by the duration of the star-forming spurt, and it suggests the galaxy once converted 600 to 3000 solar masses’ worth of gas into stars a year. That far exceeds the Milky Way’s current star formation rate of about 2 solar masses per year.
Chiaki Kobayashi at the University of Hertfordshire in Hatfield, UK, is excited by the finding but warns that it raises lots of problems. “For example, it doesn’t match with the current understanding of galaxy evolution,” she says...."