The image of supermassive black hole Sagittarius A * was created using data from the Event Horizon Telescope Collaboration. At the same time several telescopes, including the Chandra X-ray Observatory, were doing observations of their own.
Credit: NASA/CXC/A. Hobart
Credit: NASA/CXC/A. Hobart
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00:00music
00:03Visit Chandra's beautiful universe.
00:06Sagittarius A-Star
00:09As the Event Horizon Telescope,
00:12known as the EHT, collected data
00:15for its remarkable new image of the Milky Way's
00:18supermassive black hole, a legion of other telescopes,
00:21including three NASA X-ray observatories in space,
00:24was also watching.
00:27Astronomers are using these observations to learn
00:30more about how the black hole in the center of the Milky Way
00:33galaxy, known as Sagittarius A-Star,
00:36Sag A-Star for short, interacts with
00:39and feeds off its environment some
00:4227,000 light-years from Earth.
00:45While the EHT observed Sag A-Star
00:48in April 2017 to make the new image,
00:51scientists in the collaboration also
00:55with facilities that detect different wavelengths
00:58of light. In this multi-wavelength
01:01observing campaign, they assembled X-ray
01:04data from NASA's Chandra X-ray Observatory,
01:07Nuclear Spectroscopic Telescope, or
01:10NuSTAR, and the Neil Gerald Swift Observatory.
01:13Telescopes outside of NASA
01:16involved included the East Asian Very Long
01:19Baseline Interferometer, or VLBI, network
01:22that observed radio emission.
01:25There was also the global 3-mm VLBI
01:28array, along with infrared data from the
01:31European Southern Observatory's Very Large Telescope
01:34in Chile. One important goal of this
01:37so-called multi-wavelength observing campaign
01:40was to catch X-ray flares, which are thought to be
01:43driven by magnetic processes similar to those seen
01:46on the Sun, but can be tens of millions of times
01:49more powerful. These flares occur
01:52approximately daily within the area of sky
01:55observed by the EHT, a region slightly
01:58larger than the event horizon of Sagittarius
02:01the point of no return for matter falling inward.
02:04Another goal was to gain
02:07a critical glimpse of what is happening on larger
02:10scales. While the EHT result
02:13shows striking similarities between Sagittarius
02:16and the previous black hole it imaged, M87,
02:19the wider picture is much more complex.
02:28Both of these goals were successfully met.
02:31The researchers managed to catch X-ray flares, or
02:34outbursts, from Sag A star during the EHT observations,
02:37a faint one seen with Chandra and Swift,
02:40and a moderately bright one seen with Chandra
02:43Astronomers have seen X-ray
02:46flares with a similar brightness to the latter with Chandra,
02:49but this is the first time that the EHT
02:52simultaneously observed Sag A star.
02:55This offers an extraordinary opportunity
02:58to identify the responsible mechanism
03:01using actual images. Astronomers
03:04were also able to learn more about the wider and
03:07complex picture of accretion, one of the
03:10biggest ongoing questions surrounding black holes
03:13is exactly how they collect, ingest,
03:16or even expel material orbiting them at near
03:19light speed, in a process known as accretion.
03:22This process is fundamental to the
03:25formation and growth of planets, stars,
03:28and black holes of all sizes throughout the universe.
03:31Scientists will be able to
03:34use the data being released today to improve
03:37and hone their theoretical models of how black holes
03:40behave and interact with their surroundings.
03:43They will continue to study this unique combination
03:46to learn more about Sag A star and black holes
03:49throughout our universe.
04:07NASA Jet Propulsion Laboratory
04:10California Institute of Technology