Featured Research

from universities, journals, and other organizations

Rare Quasar Discovered That Produces More X-rays Than Thought Possible

Date:
April 8, 2008
Source:
European Space Agency
Summary:
XMM-Newton has been surprised by a rare type of galaxy, from which it has detected a higher number of X-rays than thought possible. The observation gives new insight into the powerful processes shaping galaxies during their formation and evolution. Scientists working with XMM-Newton were looking into the furthest reaches of the universe, at celestial objects called quasars. These are vast cosmic engines that pump energy into their surroundings. It is thought an enormous black hole drives each quasar.

Artist's impression of a rare type of quasar, called a broad absorption line (BAL) quasar. Quasars are vast cosmic engines that pump energy into their surroundings. It is thought an enormous black hole drives each quasar.
Credit: ESA, Image by C. Carreau

XMM-Newton has been surprised by a rare type of galaxy, from which it has detected a higher number of X-rays than thought possible. The observation gives new insight into the powerful processes shaping galaxies during their formation and evolution.

Scientists working with XMM-Newton were looking into the furthest reaches of the universe, at celestial objects called quasars. These are vast cosmic engines that pump energy into their surroundings. It is thought an enormous black hole drives each quasar.

As matter falls into the black hole, it collects in a swirling reservoir called the accretion disc, which heats up. Computer simulations suggest that powerful radiation and magnetic fields present in the region eject some of gas from the gravitational clutches of the black hole, throwing it back into space.

This outflow has a profound effect on its surrounding galaxy. It can create turbulence in the gas throughout the galaxy, hampering star formation. Thus, understanding quasars is an important step to understanding the early history of galaxies.  

However, the structure surrounding a quasar is difficult to see because they are so distant. The light and X-rays from them takes thousands of millions of years to reach us.

About 10-20% of quasars are of a special type called BAL quasars. The BAL stands for ‘broad absorption line’ and seems to indicate that a thick cocoon of gas surrounds the quasar.

Most researchers believe that gas flows away from a BAL quasar along the equatorial direction of the accretion disc. These quasars show little X-ray emission, indicating that there is enough gas to absorb most of the X-rays given out from the region near the black hole.

But some BAL quasars appear to be spewing material out along their polar axes, at right angles to the accretion discs.

JunXian Wang, Center for Astrophysics, University of Science and Technology of China, Hefei, and his colleagues including Tinggui Wang and Hongyan Zhou, used XMM-Newton to target four such polar BAL quasars, identified by them previously. They were investigating whether the X-rays were being absorbed strongly.

XMM-Newton observed the quasars at specific times during 2006 and 2007. Two of them emitted more X-rays than the researchers anticipated, indicating that there is no veil of absorbing gas surrounding these particular quasars. “Our results can help refine the computer simulations of how these quasars work,” says Wang.

It may mean that BAL quasars are more complicated than originally thought. “Perhaps there can be both equatorial outflows and polar outflows simultaneously from these objects,” says Wang. Maybe, the outflows are even produced by similar means.

Computer simulations suggest that the polar outflows, like the gas ejected from the accretion disc, are also material falling in, turned away by fierce radiation before it comes near the black hole.

Wang and colleagues are now following this work up. They hope to monitor more BAL quasars over a longer period of time. “We need more data so that we can look into the details of the X-ray emission,” says Wang.

It seems that the more astronomers look into the distant universe, the more complex it becomes.

The findings appear in ‘XMM observations of BAL Quasars with polar outflows’ by J. Wang, P. Jiang, H. Zhou, T. Wang, X. Dong, and H. Wang, published in the Astrophysical Journal Letters on `20 March 2008.


Story Source:

The above story is based on materials provided by European Space Agency. Note: Materials may be edited for content and length.


Cite This Page:

European Space Agency. "Rare Quasar Discovered That Produces More X-rays Than Thought Possible." ScienceDaily. ScienceDaily, 8 April 2008. <www.sciencedaily.com/releases/2008/04/080407091757.htm>.
European Space Agency. (2008, April 8). Rare Quasar Discovered That Produces More X-rays Than Thought Possible. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2008/04/080407091757.htm
European Space Agency. "Rare Quasar Discovered That Produces More X-rays Than Thought Possible." ScienceDaily. www.sciencedaily.com/releases/2008/04/080407091757.htm (accessed September 18, 2014).

Share This



More Space & Time News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Boeing, SpaceX to Send Astronauts to Space Station

Boeing, SpaceX to Send Astronauts to Space Station

AFP (Sep. 17, 2014) — NASA selected Boeing and SpaceX on Tuesday to build America's next spacecraft to carry astronauts to the International Space Station (ISS) by 2017, opening the way to a new chapter in human spaceflight. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
East Coast Treated To Rare Meteor Sighting

East Coast Treated To Rare Meteor Sighting

Newsy (Sep. 16, 2014) — Numerous residents along the East Coast reported seeing a bright meteor flash through the sky Sunday night. Video provided by Newsy
Powered by NewsLook.com
Space Race Pits Bezos Vs Musk

Space Race Pits Bezos Vs Musk

Reuters - Business Video Online (Sep. 16, 2014) — Amazon CEO Jeff Bezos' startup will team up with Boeing and Lockheed to develop rocket engines as Elon Musk races to have his rockets certified. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
NASA Picks Boeing and SpaceX to Ferry Astronauts

NASA Picks Boeing and SpaceX to Ferry Astronauts

AP (Sep. 16, 2014) — NASA is a giant step closer to launching Americans again from U.S. soil. It has announced it has picked Boeing and SpaceX to transport astronauts to the International Space Station in the next few years. (Sept. 16) 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:
from the past week

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