A galaxy just over 230 million light-years away in the nearby Perseus cluster looks as if it was snatched from the dawn of time and delivered to our galactic neighborhood, new observations reveal. The galaxy, NGC 1277, formed all its stars in a quick burst roughly 10 billion years ago — less than 4 billion years after the Big Bang. Then it appears to have abruptly switched off.
Observations published in the Jan. 10 Astrophysical Journal Letters show that stars throughout the galaxy are uniformly old and formed in a 100-million-year-long flash that created new suns at a rate of up to 1,000 per year. For comparison, our Milky Way gives birth to only a few suns each year.
“There is nothing in the local universe that is similar,” says coauthor Ignacio Trujillo, a research fellow at Spain’s Instituto de Astrofísica de Canarias. “We see an extremely different star formation history in the early universe compared to today.”
Most galaxies, including our own, grow by cannibalizing other galaxies. Every time one galaxy smashes into another, new gas pours in and sparks a wave of star formation. It’s a slow process that takes billions of years. Usually, hints of this violent past show up as streams of gas and stars. NGC 1277 shows none of this.
What researchers see in NGC 1277 is a galaxy that assembled most of its mass very quickly, including a gargantuan black hole at its center. The black hole, weighing in at 17 billion suns, is one of the most massive known and much heavier than astronomers would expect to find in a galaxy the size of NGC 1277. How it got there is a mystery (SN: 4/6/13, p. 12). Contrary to the standard picture of supermassive black holes slowly growing over many billions of years, the observations make clear that NGC 1277’s black hole formed fast and has been around for a very long time.
Observations published in the Jan. 10 Astrophysical Journal Letters show that stars throughout the galaxy are uniformly old and formed in a 100-million-year-long flash that created new suns at a rate of up to 1,000 per year. For comparison, our Milky Way gives birth to only a few suns each year.
“There is nothing in the local universe that is similar,” says coauthor Ignacio Trujillo, a research fellow at Spain’s Instituto de Astrofísica de Canarias. “We see an extremely different star formation history in the early universe compared to today.”
Most galaxies, including our own, grow by cannibalizing other galaxies. Every time one galaxy smashes into another, new gas pours in and sparks a wave of star formation. It’s a slow process that takes billions of years. Usually, hints of this violent past show up as streams of gas and stars. NGC 1277 shows none of this.
What researchers see in NGC 1277 is a galaxy that assembled most of its mass very quickly, including a gargantuan black hole at its center. The black hole, weighing in at 17 billion suns, is one of the most massive known and much heavier than astronomers would expect to find in a galaxy the size of NGC 1277. How it got there is a mystery (SN: 4/6/13, p. 12). Contrary to the standard picture of supermassive black holes slowly growing over many billions of years, the observations make clear that NGC 1277’s black hole formed fast and has been around for a very long time.
