Featured Research

from universities, journals, and other organizations

Galaxy encounter fires up quasar

Date:
June 25, 2010
Source:
Royal Astronomical Society (RAS)
Summary:
Using two of the world's largest telescopes, astronomers have found evidence of a collision between galaxies driving intense activity in a highly luminous quasar. The scientists used the Very Large Telescope in Chile and the Gran Telescopio Canarias on La Palma in the Canary Islands, to study activity from the quasar SDSS J0123+00.

An image of the field around the type 2 quasar SDSS J0123+01 obtained with the OSIRIS tuneable filter on GTC. The red colour shows regions where light is emitted mainly by stars. The green colour shows emission from hot ionized gas. Yellow indicates a mixture of both. The image reveals the existence of a giant nebula of ionized gas which extends for 180 kiloparsecs (590000 light years) or 6 times the size of our galaxy, the Milky Way. The nebula encompasses a bridge of material that connects the quasar physically with the neighbouring galaxy it is interacting with.
Credit: Montserrat Villar Martin (IAA-CSIC)

Using two of the world's largest telescopes, an international team of astronomers have found evidence of a collision between galaxies driving intense activity in a highly luminous quasar. The scientists, led by Montserrat Villar Martin of the Instituto de Astrofisica de Andalucνa-CSIC in Spain, used the Very Large Telescope (VLT) in Chile and the Gran Telescopio Canarias (GTC) on La Palma in the Canary Islands, to study activity from the quasar SDSS J0123+00.

They publish their work in a paper in the journal Monthly Notices of the Royal Astronomical Society.

Several types of galaxies, known as active galaxies, emit enormous amounts of energy from their central region or nucleus, with the most luminous objects known as quasars. Most scientists argue that quasars contain a central black hole, with a mass of at least several million Suns.

The intense gravitational field created by the black hole drags material inexorably inwards. Before falling in, this material settles in an accretion disk where it becomes very hot and emits large amounts of energy responsible for most of the brightness of the quasar. Around the central quasar 'engine' is a torus (thick ring) opaque to the visible light emitted by the accretion disk. From a terrestrial perspective, if the torus is face-on then the radiation from the disk can be seen and the system is designated type 1, whereas in type 2 quasars the torus is edge-on and the radiation is concealed.

"Type 2 quasars are a family of still rather unknown galaxies," explains Montserrat Villar-Martin, who led the research team, "which so far have been investigated mostly from a statistical point of view.

"The goal of our work is to study their individual characteristics in detail. In our study we have obtained some surprising results. For example, we have observed a giant nebula of ionized gas associated with SDSS J0123+00, and signs of an interaction with a nearby galaxy.

"This strengthens the idea that activity in galaxies is partly driven by the exchange of material between the active galaxies (or quasars) and their neighbours."

Although type 2 quasars are more difficult to detect, they are unique laboratories that let astronomers study the quasar environment in great detail, thanks to the dimming of the central radiation by the surrounding torus.

In the case of SDSS J0123+00, one of the most important results is the discovery of an extended, faint nebula of ionized gas around the entire galaxy. The nebula is about six times larger than our own Milky Way Galaxy and, according to the authors, is probably made of the debris of the interaction between SDSS J0123+00 and its neighbour.

Part of the giant nebula is a bridge of material that connects the two galaxies. This strengthens the hypothesis that the quasar activity is triggered by the interaction between them, producing the accumulation of gas in the galactic central regions and providing material to feed the black hole. This process can also trigger the rapid formation of new stars.

The new results are the first based on images obtained with the tuneable filter of the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS), the instrument installed on the GTC. The OSIRIS tuneable filter allows astronomers to observe objects in narrow windows across the spectrum of visible light from red to blue, something that with older systems would need more than five thousand narrow band filters.


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. Villar-Martin M., Tadhunter C., Perez E., Humphrey A., Martinez-Sansigre A., Gonzalez Delgado R., Perez-Torres M. VLT and GTC observations of SDSS J0123 00: a type 2 quasar triggered in a galaxy encounter? Monthly Notices of the Royal Astronomical Society, 2010; (in press)

Cite This Page:

Royal Astronomical Society (RAS). "Galaxy encounter fires up quasar." ScienceDaily. ScienceDaily, 25 June 2010. <www.sciencedaily.com/releases/2010/06/100624122444.htm>.
Royal Astronomical Society (RAS). (2010, June 25). Galaxy encounter fires up quasar. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2010/06/100624122444.htm
Royal Astronomical Society (RAS). "Galaxy encounter fires up quasar." ScienceDaily. www.sciencedaily.com/releases/2010/06/100624122444.htm (accessed April 16, 2014).

Share This



More Space & Time News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA Showcases Lunar Eclipse

NASA Showcases Lunar Eclipse

AP (Apr. 15, 2014) — Star gazers in parts of North and South America got a rare treat early Tuesday morning - a total eclipse of the moon. (April 15) Video provided by AP
Powered by NewsLook.com
Spacecrafts Could Use Urine As Fuel Source

Spacecrafts Could Use Urine As Fuel Source

Newsy (Apr. 15, 2014) — New research says the urea from urine could be recycled for fuel. Urea is filtered out of wastewater when making drinking water. Video provided by Newsy
Powered by NewsLook.com
NASA Approves Mon. Space Station Supply Launch

NASA Approves Mon. Space Station Supply Launch

AP (Apr. 13, 2014) — NASA decided Sunday to stick with the planned launch of the SpaceX cargo ship, despite a critical computer outage at the space station.Liftoff is scheduled for 4:58 p.m. Monday from Cape Canaveral. (April 13) Video provided by AP
Powered by NewsLook.com
'Blood Moon' Attracts Stargazers, Conspiracy Theories

'Blood Moon' Attracts Stargazers, Conspiracy Theories

Newsy (Apr. 13, 2014) — Tuesday's total lunar eclipse will bring out both stargazers and conspiracy theorists alike as the blood red moon fills up the early morning sky. Video provided by Newsy
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