by Staff Writers
La Laguna, Spain (SPX) Jul 17, 2017
According to Einstein's theory of General Relativity when a ray of light passes close to a very massive object, the gravity of the object attracts the photons and deviates them from their intial path.
This phenomenon, known as gravitational lensing, is comparable to that produced by lenses on light rays, and acts as a sort of magnifier, changing the size and intensity of the apparent image of the original object.
Using this effect, a team of scientists from the Instituto de Astrofisica de Canarias (IAC) led by researcher Anastasio Diaz-Sanches of the Polytechnic University of Cartagena (UPT) has discovered a very distant galaxy, some 10 thousand million light years away, about a thousand times brighter than the Milky Way.
It is the brightest of the submillimetre galaxies, called this because of their very strong emissionin the far infrared. To measure it they used the Gran Telescopio Canarias (GTC) at the Roque de los Muchachos Observatory (Garafia, La Palma).
"Thanks to the gravitational lens" notes Anastasio Diaz Sanchez, a researcher at the UPCT and first author of the article " produced by a cluster of galaxies between ourselves and the source, which acts as if it was a telescope, the galaxy appears 11 times bigger and brighter than it really is, and appears as several images on an arc centred on the densest part of the cluster, which is known as an "Einstein Ring".
The advantage of this kind of amplification is that it does not distort the spectral properties of the light, which can be studied for these very distant objects as if they were much nearer".
To find this galaxies, whose discovery was recently published in an article in the Astrophysical Journal Letters, a search of the whole sky was carried out, combining the data bases of the satellites WISE (NASA) and Planck (ESA) in order to identify the brightest submillimetre galaxies.
Its light, amplified by a much nearer galaxy cluster acting as a lens, forms an image which appears much bigger than it should, and thanks to this effect they could characterize its nature and properties spectroscopically using the GTC.
Forming stars at high velocity
Susana Iglesias-Groth, an IAC astrophysicist and a co-author of the article, adds. "This type of objects harbour the most powerful star forming regions known in the universe. The next step will be to study their molecular content".
The fact that the galaxy is so bright, its light is gravitationally amplifed, and has multiple images allows us to look into its internal properties, which would otherwise not be possible with such distant galaxies.
"In the future we will be able to make more detailed studies of its star formation using interferometers such ast the Northern Extended Millimeter Array (NOEMA/IRAM),in France, and the Atacama Large Millimeter Array (ALMA), in Chile" concludes IAC researcher Helmut Dannerbauer, who is another contributor to this discovery.
Trieste, Italy (SPX) Jul 14, 2017
The dichotomy concerns the so-called angular momentum (per unit mass), that in physics is a measure of size and rotation velocity. Spiral galaxies are found to be strongly rotating, with an angular momentum higher by a factor of about 5 than ellipticals. What is the origin of such a difference? An international research team investigated the issue in a study just published in the Astrophysical J ... read more
Instituto de Astrofisica de Canarias
Stellar Chemistry, The Universe And All Within It
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement|