2019 June 19
Our Galaxy's Magnetic Center
What's the magnetic field like in the center of our Milky Way Galaxy?
To help find out, NASA's
SOFIA -- an observatory
flying in a modified 747 -- imaged the central region with an instrument known as HAWC+.
HAWC+ maps magnetism by observing
light emitted by elongated dust grains rotating in alignment with the local
Now at our
Milky Way's center is a
supermassive black hole
with a hobby of absorbing gas from
stars it has recently destroyed.
Our galaxy's black hole, though,
is relatively quiet compared to the absorption rate of the central black holes in
The featured image gives a clue as to why -- a surrounding magnetic field may either channel gas into the black hole -- which lights up its exterior, or forces gas into an
accretion-disk holding pattern, causing it to be
less active -- at least temporarily.
Inspection of the featured image -- appearing perhaps like a surreal mashup of
impasto art and
gravitational astrophysics --
brings out this telling clue by detailing the
magnetic field in and around a dusty ring surrounding
Sagittarius A*, the black hole in our
Milky Way's center.