NGC 7742 Galaxy & the black holes?

Question

The Galaxy NGC 7742 is known to have a massive black hole in the middle of it.
So why hasn't the black hole swollowed the Galaxy? Why is gas able to shoot out from the Galaxy, I thought black holes were meant to suck things inwards, not push it outwards.

Answer 1

If anything falls inside the black holes' event horizon - it's gone. No possibility of retrieval.

Anything OUTSIDE the event horizon is subjected to a standard gravitational force.

Example: If Earth were to suddenly shrink to a dimensionless point, a black hole would form, with an event horizon about 1/2 the size of a golf ball.

The moon, unaffected by the changes to Earth, would continue to orbit that little spot like normal - as all the mass of Earth hasn't moved or changed.

Same with galaxies - all the stars orbit that common center, and on occasion, a star *does* fall into the black hole, and is consumed. But, just as our sun orbits the black hole in the center of the Milkyway, it's not dangerous unless you get too close.

Answer 2

Our own Milky Way galaxy has a massive black hole in the center too. But it doesn't swallow up the galaxy just like the Sun doesn't swallow up the planets. The planets orbit the Sun and the Sun and all other stars in the galaxy orbit the black hole. There is nothing special about the gravity of a black hole. It gets weaker according to the inverse square law just like the Sun's gravity does. And it gets stronger according to the same law, just like the Sun's gravity does. If you get 10 times closer to the Sun, then its gravity pulls you 100 times stronger. If we got close enough to a black hole, like billions of times closer than we are, gravity would pull us so hard that relativistic effects would come into play, but that is only at REALLY close distances.

Answer 3

Black holes do not shoot out gas, what they are ejecting is energy.
The reason why the black hole does not swallow the whole Galaxy, is because the black hole uses gravity to pull in the objects, but when the objects are out side the pull of the gravity from the black hole, theire is nothing to be pulled in.
Just like or solar system, after you go out so for, the gravity of the sun no longer has enough pull to hold objects in orbit around it.

When you look at a photo of a galaxy, I don't think you relies the great distance across the galaxy, and how much distance is between each star and planet.

I'm not for sure this distance is exact, but ther galaxy that we live in is over one hundred million light years across.

Answer 4

Black holes don't "suck" things in, any more than a star of the same mass would. Imagine that NGC7742 had a (dark) star of mass 10,000 times our sun at its center. The gravity effect would be the same.

As gas and dust falls toward this massive star (or black hole), it doesn't fall straight in. It rotates around the BH, gets electrically charged, and some of it hits the other gas and dust falling in. This "hit" is at very high speeds, so some of it bounces off before it gets to the BH. This forms the jet that shoots out.

Answer 5

There is a black hole in the middle of every Galaxy. That furnishes the gravity that holds everything in orbit around the Galaxy center. This gravity is so large that it may be 100 light years across.The forces are so great I doubt that we could even imagine it.

Answer 6

Even the immense gravity of super-massive black holes has a limited range. If you double the distance from any black hole, its gravitational strength weakens by a factor of four.