Tuesday, February 28, 2023

3895 - MILKY WAY & ANDROMEDA - galaxies.

 

-  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                                                                                                                         

----------------------------------------------------------------------------------------

-----  Comments appreciated and Pass it on to whomever is interested. ---

---   Some reviews are at:  --------------     http://jdetrick.blogspot.com ----- 

--  email feedback, corrections, request for copies or Index of all reviews

---  to:  ------    jamesdetrick@comcast.net  ------  “Jim Detrick”  -----------

--------------------- ---  Tuesday, February 28, 2023  ---------------------------

 

 

 

 

         

 

-

 

 

 

 

           

 

 

No comments:

Post a Comment