Featured Research

from universities, journals, and other organizations

Hubble finds quasars acting as gravitational lenses

Date:
March 15, 2012
Source:
Space Telescope Science Institute (STScI)
Summary:
Astronomers have found several examples of galaxies containing quasars, which act as gravitational lenses, amplifying and distorting images of galaxies aligned behind them.

SDSS J1005+4016. Astronomers using NASA's Hubble Space Telescope have found several examples of galaxies containing quasars, which act as gravitational lenses, amplifying and distorting images of galaxies aligned behind them. Quasars are among the brightest objects in the universe, far outshining the total starlight of their host galaxies. Quasars are powered by supermassive black holes.
Credit: NASA, ESA, and F. Courbin (EPFL, Switzerland)

Astronomers using NASA's Hubble Space Telescope have found several examples of galaxies containing quasars, which act as gravitational lenses, amplifying and distorting images of galaxies aligned behind them.

Related Articles


Quasars are among the brightest objects in the universe, far outshining the total starlight of their host galaxies. Quasars are powered by supermassive black holes.

To find these rare cases of galaxy-quasar combinations acting as lenses, a team of astronomers led by Frederic Courbin at the Ecole Polytechnique Federale de Lausanne (EPFL, Switzerland) selected 23,000 quasar spectra in the Sloan Digital Sky Survey (SDSS). They looked for the spectral imprint of galaxies at much greater distances that happened to align with foreground galaxies. Once candidates were identified, Hubble's sharp view was used to look for gravitational arcs and rings (which are indicated by the arrows in these three Hubble photos) that would be produced by gravitational lensing.

Quasar host galaxies are hard or even impossible to see because the central quasar far outshines the galaxy. Therefore, it is difficult to estimate the mass of a host galaxy based on the collective brightness of its stars. However, gravitational lensing candidates are invaluable for estimating the mass of a quasar's host galaxy because the amount of distortion in the lens can be used to estimate a galaxy's mass.

The next step for the team is to build a catalog of "quasar-lenses" that will allow them to determine masses for a statistically significant number of quasar host galaxies and to compare them with galaxies without quasars. With the numerous wide-field surveys that will start in the near future or that are already started, hundreds of thousands of quasars will be accessible for looking for lensing effects.

The team involved in this research includes: F. Courbin, C. Faure, F. Rerat, M. Tewes, and G. Meylan (EPFL, Switzerland), S.G. Djorgovski, A. Mahabal (Caltech), D. Stern (JPL), T. Boroson (NOAO), D. Sluse (Bonn University, Germany), and R. Dheeraj (University of Maryland). The full study will be published in the journal Astronomy and Astrophysics.


Story Source:

The above story is based on materials provided by Space Telescope Science Institute (STScI). Note: Materials may be edited for content and length.


Journal Reference:

  1. F. Courbin, C. Faure, S. G. Djorgovski, F. Rerat, M. Tewes, G. Meylan, D. Stern, A. Mahabal, T. Boroson, R. Dheeraj, D. Sluse. Three QSOs acting as strong gravitational lenses. Astronomy & Astrophysics, 2011; (accepted) [link]

Cite This Page:

Space Telescope Science Institute (STScI). "Hubble finds quasars acting as gravitational lenses." ScienceDaily. ScienceDaily, 15 March 2012. <www.sciencedaily.com/releases/2012/03/120315094455.htm>.
Space Telescope Science Institute (STScI). (2012, March 15). Hubble finds quasars acting as gravitational lenses. ScienceDaily. Retrieved March 4, 2015 from www.sciencedaily.com/releases/2012/03/120315094455.htm
Space Telescope Science Institute (STScI). "Hubble finds quasars acting as gravitational lenses." ScienceDaily. www.sciencedaily.com/releases/2012/03/120315094455.htm (accessed March 4, 2015).

Share This


More From ScienceDaily



More Space & Time News

Wednesday, March 4, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: SpaceX Launches Rocket, Satellites on Board

Raw: SpaceX Launches Rocket, Satellites on Board

AP (Mar. 2, 2015) — SpaceX launched it&apos;s 16th Falcon 9 rocket from Cape Canaveral, Florida on Sunday night. The rocket was carrying two commercial communications satellites. (March 2) Video provided by AP
Powered by NewsLook.com
NASA EDGE: SMAP Launch

NASA EDGE: SMAP Launch

NASA (Mar. 2, 2015) — Join NASA EDGE as they cover the launch of the Soil Moisture Active Passive (SMAP) spacecraft live from Vandenberg Air Force Base.  Special guests include NASA Administrator Charlie Bolden, SMAP Project System Engineer Shawn Goodman and Lt Col Brande Walton and Joseph Sims from the Air Force.  No word on the Co-Host&apos;s whereabouts. Video provided by NASA
Powered by NewsLook.com
Astronauts Leave Space Station for Third Spacewalk

Astronauts Leave Space Station for Third Spacewalk

Reuters - News Video Online (Mar. 1, 2015) — NASA Commander Barry Wilmore and Flight Engineer Terry Virts perform their third spacewalk in eight days outside the International Space Station. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Spacesuit Water Leaks Not An Issue On Latest ISS Walk

Newsy (Mar. 1, 2015) — Astronauts are ahead of schedule with hardware upgrades to the International Space Station, despite last week&apos;s spacesuit water leak scare. 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:

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