A cluster of galaxies is shown with many galaxies around the cluster center. A close look at this center shows that it is encompassed by a narrow ring of light. Please see the explanation for more detailed information.
图中显示的是一团星系，许多星系围绕着星系团的中心。仔细观察星系中心，可以发现它被一圈狭窄的光环所包围。有关更多详细信息，请参阅说明。
See Explanation. Clicking on the picture will download the highest resolution version available.
请参阅说明。单击图片将下载可用的最高分辨率版本。
2023年6月9日 Pandora’s Cluster of Galaxies Image Credit: NASA, ESA, CSA, Ivo Labbe (Swinburne), Rachel Bezanson (University of Pittsburgh), Processing: Alyssa Pagan (STScI) Explanation: This deep field mosaicked image presents a stunning view of galaxy cluster Abell 2744 from the James Webb Space Telescope’s NIRCam. Also dubbed Pandora’s Cluster, Abell 2744 itself appears to be a ponderous merger of three different massive galaxy clusters some 3.5 billion light-years away toward the constellation Sculptor. Dominated by dark matter, the mega-cluster warps and distorts the fabric of spacetime, gravitationally lensing even more distant objects. Redder than the Pandora cluster galaxies many of the lensed sources are very distant galaxies in the early Universe, stretched and distorted into arcs. Of course distinctive diffraction spikes mark foreground Milky Way stars….
2022年7月5日 A Molten Galaxy Einstein Ring Image Credit: ESA/Hubble & NASA, S. Jha; Processing: Jonathan Lodge Explanation: It is difficult to hide a galaxy behind a cluster of galaxies. The closer cluster’s gravity will act like a huge lens, pulling images of the distant galaxy around the sides and greatly distorting them. This is just the case observed in the featured image recently re-processed image from the Hubble Space Telescope. The cluster GAL-CLUS-022058c is composed of many galaxies and is lensing the image of a yellow-red background galaxy into arcs seen around the image center. Dubbed a molten Einstein ring for its unusual shape, four images of the same background galaxy have been identified. Typically, a foreground galaxy cluster can only create such smooth arcs…
2021年11月17日 NGC 3314: When Galaxies Overlap Image Credit: NASA, ESA, Hubble; Processing & Copyright: William Ostling (The Astronomy Enthusiast) Explanation: Why doesn’t the nearby galaxy create a gravitational lensing effect on the background galaxy? It does, but since both galaxies are so nearby, the angular shift is much smaller than the angular sizes of the galaxies themselves. The featured Hubble image of NGC 3314 shows two large spiral galaxies which happen to line up exactly. The foreground spiral NGC 3314a appears nearly face-on with its pinwheel shape defined by young bright star clusters. Against the glow of the background galaxy NGC 3314b, though, dark swirling lanes of interstellar dust can also be seen tracing the nearer spiral’s structure. Both galaxies appear on the edge of…
2021年11月02日 SN Requiem: A Supernova Seen Three Times So Far Image Credit: NASA, ESA, Hubble; Data: S. A. Rodney (U. South Carolina) et al.; Image Processing: J. DePasquale (STScI) Explanation: We’ve seen this same supernova three times — when will we see it a fourth? When a distant star explodes in a supernova, we’re lucky if we see it even once. In the case of AT 2016jka (“SN Requiem”), because the exploding star happened to be lined up behind the center of a galaxy cluster (MACS J0138 in this case), a comparison of Hubble Space Telescope images demonstrate that we saw it three times. These three supernova images are highlighted in circles near the bottom of the left frame taken in 2016. On the right…
2021年04月11日 When Black Holes Collide Video Credit & Copyright: Simulating Extreme Spacetimes Collaboration Explanation: What happens when two black holes collide? This extreme scenario occurs in the centers of many merging galaxies and multiple star systems. The featured video shows a computer animation of the final stages of such a merger, while highlighting the gravitational lensing effects that would appear on a background starfield. The black regions indicate the event horizons of the dynamic duo, while a surrounding ring of shifting background stars indicates the position of their combined Einstein ring. All background stars not only have images visible outside of this Einstein ring, but also have one or more companion images visible on the inside. Eventually the two black holes coalesce. The end stages…
