Featured Research

from universities, journals, and other organizations

Organic conundrum in Large Magellanic Cloud

Date:
June 23, 2014
Source:
Royal Astronomical Society (RAS)
Summary:
A group of organic chemicals that are considered carcinogens and pollutants today on Earth, but are also thought to be the building blocks for the origins of life, may hold clues to how carbon-rich chemicals created in stars are processed and recycled in space.

Spitzer image of the Large Magellanic Cloud.
Credit: NASA/JPL-Caltech/STScI

A group of organic chemicals that are considered carcinogens and pollutants today on Earth, but are also thought to be the building blocks for the origins of life, may hold clues to how carbon-rich chemicals created in stars are processed and recycled in space.

Scientists have studied how polycyclic aromatic hydrocarbons (PAHs) are created in an aging population of stars in the Milky Way's satellite galaxy, the Large Magellanic Cloud. They have found that the types of PAH found in the atmospheres of these stars are much more varied than the PAHs observed in our own galaxy. The results will be presented by Dr Mikako Matsuura of UCL on Monday 23 June at the National Astronomy Meeting in Portsmouth.

"We were surprised because previous measurements of PAHs in interstellar dust in the Large Magellanic Cloud were very similar to those in the Milky Way," said Matsuura. "Our studies suggest these organic molecules are processed and change their composition soon after they are ejected by dying stars to fill the matter within the galaxy. Dying stars in the neighbouring galaxy are richer in carbon than the Milky Way's stars, so are more likely to trigger these wide varieties of organic compounds."

Matsuura and an international team observed 24 carefully selected stars with the Spitzer Space Telescope and analysed the light to find features linked to PAHs. Stars are powered by nuclear fusion in their cores, converting hydrogen to helium. Towards the end of their life, low-mass stars like the Sun consume all their hydrogen in the stellar core and start to convert helium to oxygen and carbon. Eventually, they run out of fuel and expel their outer layers, creating a nebula around a central white dwarf. The gas and molecules from this nebula are mixed over time into the Interstellar Medium. The team focused their study on stars that appeared to be in the process of fusing carbon.

"We think that, as the central star evolves, the increasingly energetic radiation effects the compositions of the PAHs, leading to more varieties. However, once the PAHs are mixed into the Interstellar medium, this variability decreases," said Matsuura. "One possibility for this contrast is that ultraviolet radiation might change the profiles of the PAHs. Another is that PAHs are re-processed further in the Interstellar Medium, changing their composition."


Story Source:

The above story is based on materials provided by Royal Astronomical Society (RAS). Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Matsuura, J. Bernard-Salas, T. Lloyd Evans, K. M. Volk, B. J. Hrivnak, G. C. Sloan, Y.-H. Chu, R. Gruendl, K. E. Kraemer, E. Peeters, R. Szczerba, P. R. Wood, A. A. Zijlstra, S. Hony, Y. Ita, D. Kamath, E. Lagadec, Q. A. Parker, W. A. Reid, T. Shimonishi, H. Van Winckel, P. M. Woods, F. Kemper, M. Meixner, M. Otsuka, R. Sahai, B. A. Sargent, J. L. Hora, I. McDonald. Spitzer Space Telescope spectra of post-AGB stars in the Large Magellanic Cloud - polycyclic aromatic hydrocarbons at low metallicities. Monthly Notices of the Royal Astronomical Society, 2014; 439 (2): 1472 DOI: 10.1093/mnras/stt2495

Cite This Page:

Royal Astronomical Society (RAS). "Organic conundrum in Large Magellanic Cloud." ScienceDaily. ScienceDaily, 23 June 2014. <www.sciencedaily.com/releases/2014/06/140623092333.htm>.
Royal Astronomical Society (RAS). (2014, June 23). Organic conundrum in Large Magellanic Cloud. ScienceDaily. Retrieved September 30, 2014 from www.sciencedaily.com/releases/2014/06/140623092333.htm
Royal Astronomical Society (RAS). "Organic conundrum in Large Magellanic Cloud." ScienceDaily. www.sciencedaily.com/releases/2014/06/140623092333.htm (accessed September 30, 2014).

Share This



More Space & Time News

Tuesday, September 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Water You Drink Might Be Older Than The Sun

The Water You Drink Might Be Older Than The Sun

Newsy (Sep. 27, 2014) Researchers at the University of Michigan simulated the birth of planets and our sun to determine whether water in the solar system predates the sun. Video provided by Newsy
Powered by NewsLook.com
First Woman Cosmonaut in 17 Years Blasts Off for ISS

First Woman Cosmonaut in 17 Years Blasts Off for ISS

AFP (Sep. 26, 2014) A Russian Soyuz spacecraft carrying an American astronaut and two Russian cosmonauts, including the first woman cosmonaut in 17 years, blasted off on schedule Friday. Duration: 00:35 Video provided by AFP
Powered by NewsLook.com
Water Discovery On Small Planet Could Be Key To Earth 2.0

Water Discovery On Small Planet Could Be Key To Earth 2.0

Newsy (Sep. 25, 2014) Scientists have discovered traces of water in the atmosphere of a distant, Neptune-sized planet. Video provided by Newsy
Powered by NewsLook.com
Raw: US-Russian Crew Lifts Off for Space Station

Raw: US-Russian Crew Lifts Off for Space Station

AP (Sep. 25, 2014) A U.S.-Russian space crew has blasted off successfully for the International Space Station. The Russian Soyuz-TMA14M spacecraft lifted off from the Russian-leased Baikonur launch facility in Kazakhstan. (Sept. 25) 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