Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble Finds Quasars Acting as Gravitational Lenses

16.03.2012
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.


NASA, ESA, and F. Courbin (EPFL, Switzerland)

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. 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.

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.

Credit: NASA, ESA, and F. Courbin (EPFL, Switzerland)

For images and more information about Hubble and this study, visit:

http://hubblesite.org/news/2012/14
http://www.nasa.gov/hubble
For additional information, contact:
Ray Villard
Space Telescope Science Institute, Baltimore, Md.
410-338-4514
villard@stsci.edu
Frederic Courbin / Georges Meylan
Ecole Polytechnique Federale de Lausanne (EPFL), Versoix, Switzerland
011-41-22-379-24-18 / 011-41-22-379-24-25 and 011-41-21-693-06-44
frederic.courbin@epfl.ch
georges.meylan@epfl.ch
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Ray Villard | Newswise Science News
Further information:
http://www.stsci.edu

More articles from Physics and Astronomy:

nachricht New Boost for ToCoTronics
23.05.2019 | Julius-Maximilians-Universität Würzburg

nachricht The geometry of an electron determined for the first time
23.05.2019 | Universität Basel

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Plumbene, graphene's latest cousin, realized on the 'nano water cube'

23.05.2019 | Materials Sciences

New flatland material: Physicists obtain quasi-2D gold

23.05.2019 | Materials Sciences

New Boost for ToCoTronics

23.05.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>