With the help of NASA's Hubble Space Telescope, astronomers were able to find an answer to question as to how the universe's largest elliptical galaxies continue to make stars long after their peak years of star birth.

Astronomers said that in their research they have combined data from Hubble telescope and ground-based and space telescopes. Two independent teams working on the topic came to know that the black hole, jets, and newborn are part of a self-regulating cycle.

Study's lead researcher Megan Donahue of Michigan State University explained the phenomenon that the atmosphere can have material in different forms, just like our own atmosphere has gas, clouds and rain.

In this case when jets push gas outwards from the galaxy's center, some of the gas cools and changes into precipitation as cold mass that falls back into the galaxy's center like rainfall. Gradually, the raindrops cool enough to a level to become star-forming clouds of molecular gas.

"We know that these showers are linked to the jets because they're found in filaments and tendrils that wrap around the jets or hug the edges of giant bubbles that the jets have inflated", said Grant Tremblay from Yale University, author of the second study.

For past so many years, it was being considered as to why galaxies awash in gas do not turn all of the gas into stars. The Hubble telescope helped showing where the old and new stars are.