Featured Research

from universities, journals, and other organizations

'Hidden' galaxies of the universe have lower amounts of heavier elements

Date:
June 14, 2011
Source:
University of Copenhagen
Summary:
A unique example of some of the lowest surface brightness galaxies in the universe have been found by an international team of astronomers. The galaxy has lower amounts of heavier elements than other known galaxies of this type. The discovery means that small low surface brightness galaxies may have more in common with the first galaxies formed shortly after the Big Bang than previously thought.

The galaxy ESO 546G-34 is small faint and unevolved low surface brightness galaxy of dwarf-type, which makes it somewhat similar to the Small Magellanic Cloud (companion galaxy to the Milky Way) in appearance. ESO 546G-34 has an extremely low abundance of heavier elements and contains at least 50 percent gas, which also makes it similar to the small galaxies that were abundant in the early universe.
Credit: ESO

A unique example of some of the lowest surface brightness galaxies in the universe have been found by an international team of astronomers lead by the Niels Bohr Institute. The galaxy has lower amounts of heavier elements than other known galaxies of this type. The discovery means that small low surface brightness galaxies may have more in common with the first galaxies formed shortly after the Big Bang than previously thought.

Related Articles


The results have been published in Monthly Notices of the Royal Astronomical Society Letters.

As the name implies, the galaxies are faint and therefore difficult to find and challenging to observe. The galaxy called ESO 546-G34 is a nearly 20 year old observation that no one had previously taken much notice of. The observation has now been analysed using new methods and it is only now that astronomers have realised how special it is.

"The galaxy gives us an idea of how the galaxies must have looked before star formation really got going," explains Lars Mattsson, an astrophysicist at the Dark Cosmology Centre at the Niels Bohr Institute, University of Copenhagen. The discovery was made in collaboration with astronomers at Uppsala University and the Astronomical Observatory in Kiev.

The evolution of galaxies

A galaxy consists of many millions or billions of stars. Stars are formed when giant gas clouds condense and form a ball of glowing gas -- a star. A star produces energy through the fusion of hydrogen into helium, which fuses into carbon and oxygen and further into heavier and heavier elements. The process of conversion from gases to heavier elements takes anywhere from hundreds of thousands of years to billions of years.

Most of the known galaxies that have only formed small amounts of the heavy elements are young galaxies that are undergoing gigantic outbursts of star formation. This makes them incredibly bright and easier to observe. One type of galaxy with bursts of star formation is called blue compact galaxies, as newly formed stars emit a bluish light.

'Unevolved' dwarf galaxy

The galaxy that has been observed is small and contains only extremely small amounts of the heavier elements. That it consists mostly of the gases hydrogen and helium and is so faint means that it has only just begun to form stars.

"Our analysis shows that while a large, mature galaxy like our own galaxy, the Milky Way, is composed of around 15-20 percent gas, this faint little galaxy is composed of up to 50 percent gas and is very poor in heavier elements. This means that it is very unevolved," explains Lars Mattsson.

The theory is that the very small faint galaxies collide with each other and the greater concentration of gas material and dynamical disturbance boosts star formation and thereby form the larger blue, compact galaxies.

"ESO 546-G34 is a left over dwarf galaxy that doesn't seem to have collided with other galaxies. This gives us unique insight into how the earliest galaxies in the universe may have looked," explains Lars Mattsson.


Story Source:

The above story is based on materials provided by University of Copenhagen. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lars Mattsson, Leonid S. Pilyugin, Nils Bergvall. ESO 546−G34: the most-metal-poor, low surface brightness galaxy? Monthly Notices of the Royal Astronomical Society: Letters, 2011; DOI: 10.1111/j.1745-3933.2011.01077.x

Cite This Page:

University of Copenhagen. "'Hidden' galaxies of the universe have lower amounts of heavier elements." ScienceDaily. ScienceDaily, 14 June 2011. <www.sciencedaily.com/releases/2011/06/110614115640.htm>.
University of Copenhagen. (2011, June 14). 'Hidden' galaxies of the universe have lower amounts of heavier elements. ScienceDaily. Retrieved November 25, 2014 from www.sciencedaily.com/releases/2011/06/110614115640.htm
University of Copenhagen. "'Hidden' galaxies of the universe have lower amounts of heavier elements." ScienceDaily. www.sciencedaily.com/releases/2011/06/110614115640.htm (accessed November 25, 2014).

Share This


More From ScienceDaily



More Space & Time News

Tuesday, November 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Soyuz Spacecraft Docks With International Space Station: NASA

Soyuz Spacecraft Docks With International Space Station: NASA

AFP (Nov. 24, 2014) A Russian Soyuz spacecraft carrying Italy's first female astronaut safely docks with the International Space Station, according to NASA. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Multi-National Crew Safely Docks at Space Station

Multi-National Crew Safely Docks at Space Station

Reuters - US Online Video (Nov. 24, 2014) A Russian Soyuz rocket delivers a multi-national trio to the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Raw: Soyuz Docks With Int'l Space Station

Raw: Soyuz Docks With Int'l Space Station

AP (Nov. 23, 2014) A Russian capsule carrying three astronauts from Russia, the United States and Italy has arrived at the International Space Station. (Nov. 23) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins