They may be little, but they pack a big star-forming punch. New observations from NASA's Hubble Space Telescope show small galaxies, also known as dwarf galaxies, are responsible for forming a large proportion of the universe's stars.
Studying this early epoch of the universe's history is critical to fully understanding how these stars formed and how galaxies grew and evolved 3.5 to 6 billion years after the beginning of the universe. The result supports a decade-long investigation into whether there is a link between a galaxy's mass and its star-forming activity, and helps paint a consistent picture of events in the early universe.
Hiding among these thousands of galaxies are faint dwarf galaxies residing in the early universe, between 2 and 6 billion years after the big bang, an important time period when most of the stars in the universe were formed. Some of these galaxies are undergoing starbursts.
Image Credit: NASA and ESA
"We already suspected these kinds of galaxies would contribute to the early wave of star formation, but this is the first time we've been able to measure the effect they actually had," said Hakim Atek of the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland, lead author of the study published in the June 19 online issue of The Astrophysical Journal. "They appear to have had a surprisingly huge role to play."
Previous studies of star-forming galaxies were restricted to the analysis of mid- or high-mass galaxies, leaving out the numerous dwarf galaxies that existed in this era of prolific star formation. Astronomers conducted a recent study using data from Hubble's Wide Field Camera 3 (WFC3) to take a further and significant step forward in understanding this formative era by examining a sample of starburst galaxies in the young universe. Starburst galaxies form stars at a furiously fast rate, far above what is considered by experts to be a normal rate of star formation.
The infrared capabilities of WFC3 have allowed astronomers to finally calculate how much these low-mass dwarf galaxies contributed to the star population in our universe.
"These galaxies are forming stars so quickly they could actually double their entire mass of stars in only 150 million years -- an incredibly short astronomical timescale," adds co-author Jean-Paul Kneib, also of EPFL.
Researchers say such massive growth would take most “normal” galaxies 1 to 3 billion years.
In addition to adding new insight to how and where the stars in our universe formed, this latest finding may also help to unravel the secrets of galactic evolution. Galaxies evolve through a jumble of complex processes. As galaxies merge, they are consumed by newly-formed stars that feed on their combined gases, and exploding stars and supermassive black holes emit galactic material – a process that depletes the mass of a galaxy.
It is unusual to find a galaxy in a state of starburst, which suggests to researchers starburst galaxies are the result of an unusual incident in the past, such as a violent merger.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.
For images and more information about Hubble, visit:
Ray Villard | Eurek Alert!
New NASA study improves search for habitable worlds
20.10.2017 | NASA/Goddard Space Flight Center
Physics boosts artificial intelligence methods
19.10.2017 | California Institute of Technology
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research