星系团Abell 370及后方的天体

星系团Abell 370及后方的天体

ByNASA中文

2023年9月12日 Galaxy Cluster Abell 370 and Beyond Image Credit: NASA, ESA, Jennifer Lotz and the HFF Team (STScI) Explanation: Some 4 billion light-years away, massive galaxy cluster Abell 370 is captured in this sharp Hubble Space Telescope snapshot. The cluster of galaxies only appears to be dominated by two giant elliptical galaxies and infested with faint arcs. In reality, the fainter, scattered bluish arcs, along with the dramatic dragon arc below and left of center, are images of galaxies that lie far beyond Abell 370. About twice as distant, their otherwise undetected light is magnified and distorted by the cluster’s enormous gravitational mass, overwhelmingly dominated by unseen dark matter. Providing a tantalizing glimpse of galaxies in the early universe, the effect is known as gravitational…

韦伯的首张深场影像

韦伯的首张深场影像

ByNASA中文

2023年7月15日 Webb’s First Deep Field Image Credit: NASA, ESA, CSA, STScI, NIRCam Explanation: This stunning infrared image was released one year ago as the James Webb Space Telescope began its exploration of the cosmos. The view of the early Universe toward the southern constellation Volans was achieved in 12.5 hours of exposure with Webb’s NIRCam instrument. Of course the stars with six spikes are well within our own Milky Way. Their diffraction pattern is characteristic of Webb’s 18 hexagonal mirror segments operating together as a single 6.5 meter diameter primary mirror. The thousands of galaxies flooding the field of view are members of the distant galaxy cluster SMACS0723-73, some 4.6 billion light-years away. Luminous arcs that seem to infest the deep field are even more…

韦伯的首张深场影像

韦伯的首张深场影像

ByNASA中文

2022年7月13日 Webb’s First Deep Field Image Credit: NASA, ESA, CSA, STScI, NIRCam Explanation: This is the deepest, sharpest infrared image of the cosmos so far. The view of the early Universe toward the southern constellation Volans was achieved in 12.5 hours of exposure with the NIRCam instrument on the James Webb Space Telescope. Of course the stars with six visible spikes are well within our own Milky Way. That diffraction pattern is characteristic of Webb’s 18 hexagonal mirror segments operating together as a single 6.5 meter diameter primary mirror. The thousands of galaxies flooding the field of view are members of the distant galaxy cluster SMACS0723-73, some 4.6 billion light-years away. Luminous arcs that seem to infest the deep field are even more distant galaxies…

重力的笑容

重力的笑容

ByNASA中文

2022年5月11日 Gravity’s Grin Image Credit: X-ray – NASA / CXC / J. Irwin et al. ; Optical – NASA/STScI Explanation: Albert Einstein’s general theory of relativity, published over 100 years ago, predicted the phenomenon of gravitational lensing. And that’s what gives these distant galaxies such a whimsical appearance, seen through the looking glass of X-ray and optical image data from the Chandra and Hubble space telescopes. Nicknamed the Cheshire Cat galaxy group, the group’s two large elliptical galaxies are suggestively framed by arcs. The arcs are optical images of distant background galaxies lensed by the foreground group’s total distribution of gravitational mass. Of course, that gravitational mass is dominated by dark matter. The two large elliptical “eye” galaxies represent the brightest members of their own…

爱因斯坦的引力透镜十字架

爱因斯坦的引力透镜十字架

ByNASA中文

2021年10月17日 The Einstein Cross Gravitational Lens Image Credit & License: J. Rhoads (Arizona State U.) et al., WIYN, AURA, NOIRLab, NSF Explanation: Most galaxies have a single nucleus — does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image. The central cloverleaf is rather light emitted from a background quasar. The gravitational field of the visible foreground galaxy breaks light from this distant quasar into four distinct images. The quasar must be properly aligned behind the center of a massive galaxy for a mirage like this to be evident. The general effect is known as gravitational lensing, and this specific case is known as the Einstein Cross. Stranger still,…

Abell 3827：有星系吞食的星系团之引力透镜

Abell 3827：有星系吞食的星系团之引力透镜

ByNASA中文

2021年8月23日 Abell 3827: Cannibal Cluster Gravitational Lens Image Credit: ESA/Hubble & NASA, R. Massey Explanation: Is that one galaxy or three? Toward the right of the featured Hubble image of the massive galaxy cluster Abell 3827 is what appears to be a most unusual galaxy — curved and with three centers. A detailed analysis, however, finds that these are three images of the same background galaxy — and that there are at least four more images. Light we see from the single background blue galaxy takes multiple paths through the complex gravity of the cluster, just like a single distant light can take multiple paths through the stem of a wine glass. Studying how clusters like Abell 3827 and their component galaxies deflect distant light…