UGC 12591：已知自旋最快的星系

UGC 12591：已知自旋最快的星系

ByNASA中文

2020 February 19 UGC 12591: The Fastest Rotating Galaxy Known Image Credit: NASA, ESA, Hubble; Processing & Copyright: Leo Shatz Explanation: Why does this galaxy spin so fast? To start, even identifying which type of galaxy UGC 12591 is difficult — featured on the lower left, it has dark dust lanes like a spiral galaxy but a large diffuse bulge of stars like a lenticular. Surprisingly observations show that UGC 12591 spins at about 480 km/sec, almost twice as fast as our Milky Way, and the fastest rotation rate yet measured. The mass needed to hold together a galaxy spinning this fast is several times the mass of our Milky Way Galaxy. Progenitor scenarios for UGC 12591 include slow growth by accreting ambient matter, or…

超快速自旋的旋涡星系

超快速自旋的旋涡星系

ByGotthew

2019 November 5 Spiral Galaxies Spinning Super-Fast Image Credit: Top row: NASA, ESA, Hubble, P. Ogle & J. DePasquale (STScI); Bottom row: SDSS, P. Ogle & J. DePasquale (STScI) Explanation: Why are these galaxies spinning so fast? If you estimated each spiral’s mass by how much light it emits, their fast rotations should break them apart. The leading hypothesis as to why these galaxies don’t break apart is dark matter — mass so dark we can’t see it. But these galaxies are even out-spinning this break-up limit — they are the fastest rotating disk galaxies known. It is therefore further hypothesized that their dark matter halos are so massive — and their spins so fast — that it is harder for them to form stars…