Group of galaxies found to bend the light of remote galaxies

[telfrow]

<i>The discovery of a new class of gravitational lenses, the groups of galaxies, by an international team of astronomers using the Canada-France-Hawaii Legacy Survey (CFHTLS), comes 20 years after the publication in January 1987 of the first image of a gravitational arc, made also at CFHT with one of the first CCD cameras in operation at an observatory. <br /><br />This discovery of gravitational arcs in the center of galaxy groups is an important step in our understanding of the large scale structures of the universe. These new results will allow a better understanding of the distribution of the dark matter and the formation mechanisms of the groups of galaxies, structures intermediate in mass between galaxies and clusters of galaxies. <br /><br />Twenty years ago at CFHT, French astronomers observed for the first time galaxies distorted in giant arcs at the center of the most massive galaxy clusters. These observations brought to light one of the most spectacular effects of what is called "gravitational lensing". <br /><br />According to Einstein’s theory of General Relativity, spacetime is curved by the presence of matter. Therefore, the light passing close to an important concentration of mass will be bent. When an observer, a galaxy cluster and a remote galaxy are in nearly perfect alignment, the remote galaxy appears to the observer as one or more luminous arcs resulting from the fusion of images of the remote galaxy distorted and amplified by the galaxy cluster acting as a complex gravitational lens. The shape, brightness and distribution of these gravitational arcs bring invaluable information on the mass distribution of the lensing cluster. </i><br /><br />Link<br /> <br /><br /><b>Photo Caption:</b><i> "This example of a galaxy group lens in the CFHTLS-SL2S, called SL2SJ021408-053532, shows a very complex arc structure (in blue). Such complex arc geometries allow us to probe the details of the dark</i> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[weeman]

Very wild stuff. I was unaware that gravitational lensing had not yet been discovered from galaxy clusters. This almost has to be undeniable proof that Einstein's theory of 4th dimension spacetime is the invisible structure of the Universe. Of course, it is invisible to the observer until that observer is able to witness it through this gravitational lensing.<br /><br /><font color="yellow"> These new results will allow a better understanding of the distribution of the dark matter </font><br /><br />Does this necessarily have to deal directly with dark matter? Can it deal more with the warp of spacetime? If the light from the galaxy that is being lensed in this picture is not passing straight through the cluster, we have to assume something is lensing it, and preventing it from traveling in a straight path. I don't think this would have to mean that the only explanation is dark matter.<br /><br />If there is an entire cluster of galaxies rotating around a common center of gravity, this center of gravity would be very strong. Spacetime is warped enough so that light is bent around it, not allowing it to pass in a straight line.<br /> <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>