Fermi Gamma-ray Space Telescope was also watching
for changes in gamma-ray light from M87* during the
EHT observations. If the EHT observed changes in the
structure of the black hole’s environment, data from
these missions and other telescopes could be used to
help figure out what was going on.
Though NASA observations did not directly trace out the
historic image, astronomers used data from Chandra
and NuSTAR satellites to measure the X-ray brightness of
M87*’s jet. Scientists used this information to compare
their models of the jet and disk around the black hole
with the EHT observations. Other insights may come as
researchers continue to pore over these data.
Why It's Important
Learning about mysterious structures in the universe
provides insight into physics and allows us to test
observation methods and theories, such as Einstein’s
theory of general relativity. Massive objects deform
spacetime in their vicinity, and although the theory of
general relativity has directly been proven accurate for
smaller-mass objects, such as Earth and the Sun, the
theory has not yet been directly proven for black holes
and other regions containing dense matter.
One of the main results of the EHT black hole imaging
project is a more direct calculation of a black hole’s mass
than ever before. Using the EHT, scientists were able to
directly observe and measure the radius of M87*’s event
horizon, or its Schwarzschild radius, and compute the
black hole’s mass. That estimate was close to the one
derived from a method that uses the motion of orbiting
stars – thus validating it as a method of mass estimation.
The size and shape of a black hole, which depend on its
mass and spin, can be predicted from general relativity
equations. General relativity predicts that this silhouette
would be roughly circular, but other theories of gravity
predict slightly different shapes. The image of M87*
shows a circular silhouette, thus lending credibility to
Einstein’s theory of general relativity near black holes.
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THE CLAPPER 2018 - 2019
The data also offer some insight into the formation and
behavior of black hole structures, such as the accretion
disk that feeds matter into the black hole and plasma
jets that emanate from its center. Scientists have
hypothesized about how an accretion disk forms, but
they’ve never been able to test their theories with direct
observation until now. Scientists are also curious about
the mechanism by which some supermassive black
holes emit enormous jets of particles traveling at near
light-speed.
These questions and others will be answered as more
data is acquired by the EHT and synthesized in computer
algorithms. Be sure to stay tuned for that and the next
expected image of a black hole – our Milky Way’s own
Sagittarius A.
Read more at: https://www.jpl.nasa.gov/edu/
news/2019/4/19/how-scientists-captured-the-first-
image-of-a-black-hole/
The Movie: Particle Fever
You don't have to be a physicist—you don't even have to
be good at math, I can certainly attest to that—to enjoy
the energy, camaraderie and giddy thrill of discovery
that radiates from the documentary "Particle Fever".
That's much of the beauty of director Mark Levinson's
film. He's taken a potentially daunting topic—the
search for the elusive and highly significant Higgs boson
particle, also known as the "God particle"—and turned
it into a movie that's not just accessible but fun, with a
surprisingly emotional payoff at the end.