![]() ![]() They pointed Keck at 62 adjacent locations of the galaxy, mapping out the spectra of stars over a region about 70,000 light-years across. Ma, together with UC Berkeley graduate student Emily Liepold (lead author on the paper published in the Astrophysical Journal Letters) and Jonelle Walsh at Texas A&M University were able to determine the 3D shape of M87 thanks to a new precision instrument mounted on the Keck II Telescope. That's likely the reason M87's central black hole is so large - it assimilated the central black holes of one or more galaxies it swallowed. Over ten times the mass of the Milky Way, M87 probably grew from the merger of many other galaxies. "Now that we know the direction of the net rotation of stars in M87 and have an updated mass of the black hole, we can combine this information with data from the Event Horizon Telescope to constrain the spin," said Chung-Pei Ma, a UC Berkeley lead investigator on the research. The stereo model of M87 and the more precise mass of the central black hole could help astrophysicists learn the black hole's spin rate. When the Event Horizon Telescope, an international collaboration of ground-based telescopes, released the first-ever image of the same black hole in 2019, the size of its pitch-black event horizon allowed researchers to calculate a mass of 6.5 billion solar masses using Einstein's theory of general relativity. Hubble observations in 1995 first measured the M87 black hole as being 2.4 billion solar masses, which astronomers deduced by clocking the speed of the gas swirling around the black hole. Tracking the stellar speeds and position allowed researchers to build a three-dimensional view of the galaxy.Īstronomers at the University of California, Berkeley, were able to determine the mass of the black hole at the galaxy's core to a high precision, estimating it at 5.4 billion times the mass of the Sun. The stellar motion was used to provide new insights into the shape of the galaxy and its rotation, and it also yielded a new measurement of the black hole's mass. Scientists made the 3D plot by measuring the motions of stars that swarm around the galaxy's supermassive central black hole. Determining the true shape of giant elliptical galaxies will help astronomers understand better how large galaxies and their central large black holes form. For example, the whole class of huge galaxies called "ellipticals" look like blobs in pictures. In most cases, astronomers must use their intuition to figure out the true shapes of deep-space objects. This stereo vision was made possible by combining the power of NASA's Hubble Space Telescope and the ground-based W. This galaxy turns out to be "triaxial," or potato-shaped. Now for the first time, astronomers have measured the three-dimensional shape of one of the biggest and closest elliptical galaxies to us, M87. Though we live in a vast three-dimensional universe, celestial objects seen through a telescope look flat because everything is so far away. It not only has a long and short axis, which defines an ellipse on a piece of graph paper, but they measured a third axis which helps define the three-dimensionality. By following the motion of stars around the center of M87, like bees around a hive, they've measured that the galaxy looks potato-shaped. They picked one of the nearest elliptical galaxies to Earth, M87, located 55 million light-years away in the heart of the vast Virgo cluster of galaxies. Now, a century later, astronomers at last have the tools to estimate the true shape of an elliptical galaxy. They are too far away for astronomers to employ stereoscopic vision. Though the universe is three-dimensional, galaxies look flat on the sky. Others looked like cotton balls, which he called elliptical galaxies. Many were flattened spiral disks of stars. Like a kid collecting rocks, he sorted them into shapes. American astronomer Edwin Hubble realized this in the early 20th century when he used the most powerful telescope on Earth at the time to peer across the universe. Though it's estimated that the universe contains 1 trillion galaxies, they come in just a few basic shapes. Four Successful Women Behind the Hubble Space Telescope's Achievements.Characterizing Planets Around Other Stars.Measuring the Universe's Expansion Rate. ![]()
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