MADRID, 29 Sep. (EUROPA PRESS) –
Astronomers have identified 64 strong gravitational lenses that span vast cosmic distances and might transform our ability to trace the evolution of galaxies since the Big Bang.
The finding was made on the evaluation of 77 gravitational lenses taken from an initial sample of up to 5,000 lenses. chosen by a machine learning algorithm earlier this year.
ASTRO 3D and UNSW astronomer Sydney Kim-Vy Tran’s paper, published in the Astronomical Journal, presents spectroscopic confirmation of previously identified strong gravitational lensing using convolutional neural networks, developed by data scientist Colin Jacobs at ASTRO 3D and the University of Swinburne. The work is part of the ASTRO 3D Galaxy Evolution with Lenses (AGEL) survey.
“Our spectroscopy allowed us to map a 3D image of gravitational lensing to show that they are genuine and not just a random superposition,” he says. it’s a statement Dr. Tran, from the ARC Center of Excellence for All Sky Astrophysics in 3-Dimensions (ASTRO3D) and the University of New South Wales (UNSW).
“Our goal with AGEL is spectroscopically confirm regarding 100 strong gravitational lenses that can be observed from the northern and southern hemispheres throughout the year,” he says.
Gravitational lensing was first identified as a phenomenon by Einstein, who predicted that light bends around massive objects in space in the same way that light bends through a lens. In doing so, it greatly magnifies images of galaxies that we might not otherwise be able to see.
SEE DARK MATTER
While it has long been used by astronomers to peer into distant galaxies, finding these cosmic magnifying glasses in the first place has been hit or miss. These magnifying glasses allow us to see objects that are millions of light years away more clearly, and they should also allow us to “see“the invisible dark matter that makes up most of the Universe.
“We know that most of the mass is dark,” says Dr. Tran. “We know that mass deflects light and therefore if we can measure how much light is deflected, we can infer how much mass must be there.”
Having much more gravitational lensing at various distances will also give us a more complete picture of the timeline going back almost to the Big Bang.
“The more magnifying glasses you have, the better chance you have of trying to inspect these more distant objects. Hopefully, we can better measure the demographics of very young galaxiessays Dr. Tran.
“Then somewhere between those first really early galaxies and us, there’s a lot of evolution going on, with little star-forming regions turning pristine gas into the sun’s first stars, the Milky Way. And so on, with these lenses at different distances, we can look at different points on the cosmic timeline to essentially track how things change over time, between the earliest galaxies and now,” he added.