M77:有活跃核心的螺旋星系

M77:有活跃核心的螺旋星系

2020 March 17 M77: Spiral Galaxy with an Active Center Image Credit: Hubble, NASA, ESA; Processing & License: Judy Schmidt Explanation: What’s happening in the center of nearby spiral galaxy M77? The face-on galaxy lies a mere 47 million light-years away toward the constellation of the Sea Monster (Cetus). At that estimated distance, this gorgeous island universe is about 100 thousand light-years across. Also known as NGC 1068, its compact and very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active Seyfert galaxies. M77 and its active core glows bright at x-ray, ultraviolet, visible, infrared, and radio wavelengths. The featured sharp image of M77 was taken by the Hubble Space Telescope and is dominated by the (visible) red…

旋涡星系M77的磁场

旋涡星系M77的磁场

2019 December 16 The Magnetic Fields of Spiral Galaxy M77 Image Credit: NASA, SOFIA, HAWC+; JPL-Caltech, Roma Tre. U.; ESA, Hubble, NuSTAR, SDSS Explanation: Can magnetic fields help tell us how spiral galaxies form and evolve? To find out, the HAWC+ instrument on NASA’s airborne (747) SOFIA observatory observed nearby spiral galaxy M77. HAWC+ maps magnetism by observing polarized infrared light emitted by elongated dust grains rotating in alignment with the local magnetic field. The HAWC+ image shows that magnetic fields do appear to trace the spiral arms in the inner regions of M77, arms that likely highlight density waves in the inflowing gas, dust and stars caused by the gravity of the galaxy’s oval shape. The featured picture superposes the HAWC+ image over diffuse…