https://phys.org/news/2020-05-universe-lenses.html Seeing the universe through new lenses: Like crystal balls for the universe's deeper mysteries, galaxies and other massive space objects can serve as lenses to more distant objects and phenomena along the same path, bending light in revelatory ways. Gravitational lensing was first theorized by Albert Einstein more than 100 years ago to describe how light bends when it travels past massive objects like galaxies and galaxy clusters. These lensing effects are typically described as weak or strong, and the strength of a lens relates to an object's position and mass and distance from the light source that is lensed. Strong lenses can have 100 billion times more mass than our sun, causing light from more distant objects in the same path to magnify and split, for example, into multiple images, or to appear as dramatic arcs or rings. The major limitation of strong gravitational lenses has been their scarcity, with only several hundred confirmed since the first observation in 1979, but that's changing ... and fast. A new study by an international team of scientists revealed 335 new strong lensing candidates based on a deep dive into data collected for a U.S. Department of Energy-supported telescope project in Arizona called the Dark Energy Spectroscopic Instrument (DESI). The study, published May 7 in The Astrophysical Journal, benefited from the winning machine-learning algorithm in an international science competition. "Finding these objects is like finding telescopes that are the size of a galaxy," said David Schlegel, a senior scientist in Lawrence Berkeley National Laboratory's (Berkeley Lab's) Physics Division who participated in the study. "They're powerful probes of dark matter and dark energy." These newly discovered gravitational lens candidates could provide specific markers for precisely measuring distances to galaxies in the ancient universe if supernovae are observed and precisely tracked and measured via these lenses, for example. more at link...... the paper: https://iopscience.iop.org/article/10.3847/1538-4357/ab7ffb Finding Strong Gravitational Lenses in the DESI DECam Legacy Survey: Abstract We perform a semi-automated search for strong gravitational lensing systems in the 9000 deg2 Dark Energy Camera Legacy Survey (DECaLS), part of the Dark Energy Spectroscopic Instrument Legacy Imaging Surveys. The combination of the depth and breadth of these surveys are unparalleled at this time, making them particularly suitable for discovering new strong gravitational lensing systems. We adopt the deep residual neural network architecture developed by Lanusse et al. for the purpose of finding strong lenses in photometric surveys. We compile a training sample that consists of known lensing systems in the Legacy Surveys and the Dark Energy Survey as well as non-lenses in the footprint of DECaLS. In this paper we show the results of applying our trained neural network to the cutout images centered on galaxies typed as ellipticals in DECaLS. The images that receive the highest scores (probabilities) are visually inspected and ranked. Here we present 335 candidate strong lensing systems, identified for the first time.
I like the idea of actually catching an event (supernova) in one of these G. lenses. To watch the brightness of the supernova rise and fall in each of its images at the four points of an Einstein cross. Please Register or Log in to view the hidden image! https://news.berkeley.edu/2015/03/05/distant-supernova-split-four-ways-by-gravitational-lens/
Question; Are the four images the lensed images of a single object hidden behind the gravitational object? If so how big is the gravitational lens? It has to be enormous!
Yes. It could be a Quasar, DM, or even a BH. Gravitational lensing is classified into strong [Einstein crosses, and weak [single objects]
