DOE/Fermi National Accelerator Laboratory
Shown here is the elliptical galaxy NGC 474 with star shells. Elliptical galaxies are characterized by their relatively smooth appearance as compared with spiral galaxies, one of which is to the left of NGC 474, which is oriented with South to the top and West to the left. The colorful neighboring spiral (NGC 470) has characteristic flocculent structure interwoven with dust lanes and spiral arms. NGC 474 is at a distance of about 31 megaparsecs (100 million light-years) from the sun in the constellation of Pisces. The region surrounding NGC 474 shows unusual structures characterized as tidal tails or shells of stars made up of hundreds of millions of stars. These features are likely due to recent (within the last billion years) mergers of smaller galaxies into the main body of NGC 474 or close passages of nearby galaxies, such as the NGC 470 spiral. For coordinate information, visit the NOIRLab webpage for this photo. (Photo: DES/NOIRLab
Doubling the Number of Known Gravitational Lenses
Machine learning key to discovery of over 1200 gravitational lenses
CosmoView Episode 19: Doubling the Number of Known Gravitational Lenses
KPNO/CTIO/NOIRLab/NSF/AURA/Legacy Imaging Survey
Gravitational lenses found in the DESI Legacy Survey data. Examples of gravitational lenses found in the DESI Legacy Survey data.
KPNO/CTIO/NOIRLab/NSF/AURA/Legacy Imaging Survey
Gravitational lens found in the DESI Legacy Survey data. An example of a gravitational lens found in the DESI Legacy Surveys data. The nearly complete circle in the middle of DESI-015.6763-14.0150 is the image of a background galaxy, gravitationally warped (lensed) by the red galaxy at the center into a near-perfect Einstein ring.
One early result of the ongoing Dark Energy Survey is the previously untold story revealed by old, giant RR Lyrae pulsating stars, which tell scientists about the region of space beyond the edge of our Milky Way. In this area nearly devoid of stars–the motion of the RR Lyrae stars hints at the presence of an enormous halo of invisible dark matter, which may provide clues to how our galaxy evolved over the last 12 billion years.
One of the Biggest Mysteries in Science
Dark matter, one of the enduring mysteries in science, is “dark” in the sense that it doesn’t emit radiation or hardly interact with anything except via its gravitational attraction. Dark matter may be responsible for some of the observed gravitational waves signals, and seeded supermassive black holes found in the center of the Milky Way and other galaxies, according to a recent study by the Kavli Institute for the Physics and Mathematics of the Universe.
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VIDEO: This is CosmoView Episode 18 for press release noirlab2103: Giant Map of the Sky Sets Stage for Ambitious DESI Survey view more
Credit: Images and Videos:
KPNO/CTIO/NOIRLab/NSF/AURA/Legacy Imaging Survey, P. Marenfeld, D. Munizaga, Lawrence Berkeley National Lab.
Music: Stellardrone - Airglow.
Astronomers using images from Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory have created the largest ever map of the sky, comprising over a billion galaxies. The ninth and final data release from the ambitious DESI Legacy Imaging Surveys sets the stage for a ground-breaking 5-year survey with the Dark Energy Spectroscopic Instrument (DESI), which aims to provide new insights into the nature of dark energy. The map was released today at the January 2021 meeting of the American Astronomical Society.
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VIDEO: CosmoView Episode 20 for press release noirlab2015: Mapping Our Sun s Backyard
Music: zero-project - The Lower Dungeons (zero-project.gr) view more
Credit: KPNO/NOIRLab/NSF/AURA/P. Marenfeld, International Gemini Observatory/Jacqueline Faherty (American Museum of Natural History)/OpenSpace/Lynette Cook
Astronomers have curated the most complete list of nearby brown dwarfs to date thanks to discoveries made by thousands of volunteers participating in the Backyard Worlds citizen science project. The list and 3D map of 525 brown dwarfs including 38 reported for the first time incorporate observations from a host of astronomical instruments including several NOIRLab facilities. The results confirm that the Sun s neighborhood appears surprisingly diverse relative to other parts of the Milky Way Galaxy.