- 3895 - MILKY WAY & ANDROMEDA - galaxies. Results suggest that very early supermassive black holes were often heavily obscured by dust, perhaps as a consequence of the intense star formation activity in their host galaxies.
-------------- 3895 - MILKY WAY & ANDROMEDA - galaxies.
- 26,000
light years away, a strange and enormous cloud is being stretched and strained
under the tremendous tidal forces of Sagittarius A*, the supermassive black
hole at the center of our Milky Way galaxy. In just 13 years, astronomers
expect this cloud, known as X7, to be torn to shreds by the extreme
environment.
-
- The doomed
cloud is 3,000 times longer than the distance from the Earth to the Sun. It provides clues to the strange and extreme
environment around a black hole 4 million times more massive than the Sun.
-
- When “X7”
was first noticed in 2007, astronomers described it as a comet-shaped object
close to the galactic center.
Sagittarius A* (Sgr A*) at the center of the Milky Way acts like gas
clouds when far from the black hole only to hold together like stars as they
draw closer in their orbits.
-
- Despite its
cometary comparison, X7 was vastly more massive than any comet, about 50 times
the mass of Earth altogether.
Astronomers have been able to watch X7 stretch and shift in real-time
over the decade. In that time, X7 grew
twice as long as it once was indicating that it is being stretched out by Sgr
A* like a noodle.
-
- A filament
like X7 is an extreme object in an extreme environment even though it’s
traveling at 490 miles per second, its orbit around the supermassive black hole
at the center of the Milky Way would take 170 years if it were to complete.
-
- Just what
type of object X7 is and where it came from is still something of a mystery.
When it was first detected, astronomers thought it might be the result of a jet
or wind blown out from a nearby star, S0-73. But looking over data from the
last 20 years, the team found the two aren’t moving in the same direction, nor
are they in quite the same three-dimensional volume.
-
- A gas
filament like X7 might have been ejected from a nearby star, or it could have
been stripped away from some other larger structure. Astronomers suspects X7 is the result of a
close scrape between two binary stars.
-
- In the
extreme tidal environment around a supermassive black hole, binary stars are
common, and so are the collisions and mergers between them. If two stars grazed
against each other, a long stream of gas and dust would be ejected from their
violent collision, which would match the shape and behavior of X7.
-
- Even though
it’s zooming around the center of our galaxy at tremendous speeds, X7 will be
ripped apart by Sagittarius A*’s tidal forces long before it completes its next
170-year orbit.
-
- In
2036, X7 will reach its periapse
passage, its closest approach to the black hole. Even though X7 is zipping around Sagittarius
A* 26,000 light years away (and its fate was sealed about 25,987 years ago),
that’s still 794,000 light years closer than the next-closest supermassive
black hole, in the dwarf galaxy Leo. This means astronomers will have a
close-up view of what happens to a gas cloud very close to a supermassive black
hole.
-
- Along with
the Keck telescopes used to observe it since 2002, the JWST is scheduled to
take a look at the Sagittarius A* and X7 in the coming months, 2023, JWST
observes in different spectra than the Keck observatory. This will give astronomers insights into its
structure of the thing.
-
- Elseware in
the Universe astronomers from have discovered a rapidly growing black hole in
one of the most extreme galaxies known in the very early Universe. The
discovery of the galaxy and the black hole at its center provides new clues on
the formation of the very first supermassive black holes.
-
- Using
observations taken with the Atacama Large Millimeter Array (ALMA), a radio
observatory sited in Chile, astronomers have determined that the galaxy, named
COS-87259, containing this new supermassive black hole is very extreme, forming
stars at a rate 1000 times that of our own Milky Way and containing over a
billion solar masses worth of interstellar dust. The galaxy shines bright from
both this intense burst of star formation and the growing supermassive black
hole at its center.
-
- The black
hole is considered to be a new type of primordial black hole, one heavily
enshrouded by cosmic “dust”, causing nearly all of its light to be emitted in
the mid-infrared range of the electromagnetic spectrum.
-
- The
researchers have also found that this growing supermassive black hole
(frequently referred to as an active galactic nucleus) is generating a strong
jet of material moving at near light speed through the host galaxy.
-
- Black holes
with masses millions to billions of times greater than that of our own Sun sit
at the center of nearly every galaxy. How these super - massive black holes
first formed remains a mystery for scientists, particularly because several of
these objects have been found when the Universe was very young.
-
- Because the
light from these sources takes so long to reach us, we see them as they existed
in the past; in this case, just 750 million years after the Big Bang, which is
approximately 5% of the current age of the Universe.
-
- The only
other class of supermassive black holes we knew about in the very early
Universe are quasars, which are active black holes that are relatively
unobscured by cosmic dust. These quasars are extremely rare at distances
similar to COS-87259, with only a few tens located over the full sky.
-
- Similar
types of objects have been found in the more local, present-day Universe. Two galaxies crash together generating an
intense starburst as well as heavy obscuration of the growing supermassive
black hole in one of the two galaxies.
-
- Astronomers
are building a much better understanding of how billion solar mass black holes
were able to form so early on in the lifetime of the Universe, as well how the
most massive galaxies first evolved.
-
February 28, 2023 MILKY WAY & ANDROMEDA -
galaxies. 3895
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--- Tuesday, February 28, 2023 ---------------------------
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