Team members chose the galaxies based on their mass, star-formation rate
, and abundances of elements that are heavier than hydrogen and helium.
The group first assessed some 500 galaxies sitting somewhere between 11 to 58 million light years away from Earth and decided which ones were the best to look at based on their mass, star-formation rate
, and presence of elements heavier than hydrogen and helium.
It is important to recall here that the EW(Ha) is a proxy of the specific star-formation rate
(sSFR) or the current star-formation compared to the total stellar mass (e.g., ).
In fact, the California Institute of Technology (Caltech) astronomers say its star-formation rate
is 45 times lower than what astronomers might expect from such a dense cloud.
In a new study, Shapley and her colleagues have delineated several properties that contribute to the high star-formation rate
in the remote Lyman-break galaxies.
Further HTTP-based research led by Michele Cignoni (University of Pisa, Italy) shows that the star-formation rate
peaked about 2 million years ago.
"This very distant, relatively typical galaxy is known to us, and we knew it was forming stars, but we had no idea what its real star-formation rate
was because there is so much dust surrounding it," study lead author Alexandra Pope, an astronomer at the University of Massachusetts Amherst, said in a (http://www.umass.edu/newsoffice/article/umass-amherst-astronomers-find-unexpected) statement .
It is critical to know the star-formation rate
in the early universe -- about 10 billion years ago -- because that was the time when most of the universe's stars formed.
From these, their star-formation rate
could be then calculated.
To assess the star-formation rate
in the clouds, the team homed in on the abundance of carbon atoms stripped of a single electron.
Although the pair is currently in a rapid star-forming phase, chances are, if they become satellites of much larger galaxies, this star-formation rate