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Do all galaxies have a black hole in the center?
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Would I be correct if I stated that all galaxies have a black hole in the center? Since other galaxies orbit around a center point in a galaxy - the barycenter, right? - I would assume at this point there must be some insane gravitational pull. Which only black holes can create, right?
(If this is a bit vague, please tell me so I can clarify!)
I am a complete newbie to astronomy in general, so sorry if this question makes no sense whatsoever.
black-hole galaxy galaxy-center
edited 8 mins ago
Community♦
1
asked 16 hours ago
FutureCake
1415
 |Â
show 1 more comment
up vote
5
down vote
favorite
Would I be correct if I stated that all galaxies have a black hole in the center? Since other galaxies orbit around a center point in a galaxy - the barycenter, right? - I would assume at this point there must be some insane gravitational pull. Which only black holes can create, right?
(If this is a bit vague, please tell me so I can clarify!)
I am a complete newbie to astronomy in general, so sorry if this question makes no sense whatsoever.
black-hole galaxy galaxy-center
edited 8 mins ago
Community♦
1
asked 16 hours ago
FutureCake
1415
4
Why do you say that it "must have some insane gravitational pull"? Stuff orbits the barycenter because it's the center of mass, it doesn't have to be a big concentration of mass. FWIW, for galaxies with a central BH, the mass of that BH is a tiny fraction of the whole galaxy's mass. It's not like the BH dominates the galaxy's gravitational structure, although of course it has a fairly big effect in the immediate vicinity of the BH.
– PM 2Ring
13 hours ago
2
Where's the black hole in the middle of every binary system that makes the stars orbit the barycenter? The mass of the stars is more than enough, you don't need them to orbit something else. Solve for a binary star system, and you'll see the same mechanism still works for n-bodies.
– Luaan
6 hours ago
@PM2Ring: While that's a fairly well-known physical result, it ignores the fundamental question: Would all that mass even be there concentrated in a galaxy without a black hole? Or are black holes essential to the formation of starts and their clustering into a galaxy?
– MSalters
1 hour ago
@Luaan If the mass of the stars is more than enough, does that mean that they will collide/merge?
– Andrew Morton
1 hour ago
@MSalters Sure, central black holes might be important in galaxy formation, but I don't see how they are relevant to star formation. And then you have to explain spiral galaxies without a central BH. Did they lose their BH, eg in a collision? If so, how did they manage to retain their spiral structure? FWIW, we still don't have a good theory to explain how super massive BHs are so massive. I suspect that we need to learn more about the role of dark matter to address these questions properly.
– PM 2Ring
49 mins ago
 |Â
show 1 more comment
up vote
5
down vote
favorite
up vote
5
down vote
favorite
Would I be correct if I stated that all galaxies have a black hole in the center? Since other galaxies orbit around a center point in a galaxy - the barycenter, right? - I would assume at this point there must be some insane gravitational pull. Which only black holes can create, right?
(If this is a bit vague, please tell me so I can clarify!)
I am a complete newbie to astronomy in general, so sorry if this question makes no sense whatsoever.
black-hole galaxy galaxy-center
edited 8 mins ago
Community♦
1
asked 16 hours ago
FutureCake
1415
Would I be correct if I stated that all galaxies have a black hole in the center? Since other galaxies orbit around a center point in a galaxy - the barycenter, right? - I would assume at this point there must be some insane gravitational pull. Which only black holes can create, right?
(If this is a bit vague, please tell me so I can clarify!)
I am a complete newbie to astronomy in general, so sorry if this question makes no sense whatsoever.
black-hole galaxy galaxy-center
black-hole galaxy galaxy-center
edited 8 mins ago
Community♦
1
asked 16 hours ago
FutureCake
1415
edited 8 mins ago
Community♦
1
asked 16 hours ago
FutureCake
1415
edited 8 mins ago
Community♦
1
edited 8 mins ago
Community♦
1
edited 8 mins ago
Community♦
1
1
asked 16 hours ago
FutureCake
1415
asked 16 hours ago
FutureCake
1415
asked 16 hours ago
FutureCake
1415
1415
4
Why do you say that it "must have some insane gravitational pull"? Stuff orbits the barycenter because it's the center of mass, it doesn't have to be a big concentration of mass. FWIW, for galaxies with a central BH, the mass of that BH is a tiny fraction of the whole galaxy's mass. It's not like the BH dominates the galaxy's gravitational structure, although of course it has a fairly big effect in the immediate vicinity of the BH.
– PM 2Ring
13 hours ago
2
Where's the black hole in the middle of every binary system that makes the stars orbit the barycenter? The mass of the stars is more than enough, you don't need them to orbit something else. Solve for a binary star system, and you'll see the same mechanism still works for n-bodies.
– Luaan
6 hours ago
@PM2Ring: While that's a fairly well-known physical result, it ignores the fundamental question: Would all that mass even be there concentrated in a galaxy without a black hole? Or are black holes essential to the formation of starts and their clustering into a galaxy?
– MSalters
1 hour ago
@Luaan If the mass of the stars is more than enough, does that mean that they will collide/merge?
– Andrew Morton
1 hour ago
@MSalters Sure, central black holes might be important in galaxy formation, but I don't see how they are relevant to star formation. And then you have to explain spiral galaxies without a central BH. Did they lose their BH, eg in a collision? If so, how did they manage to retain their spiral structure? FWIW, we still don't have a good theory to explain how super massive BHs are so massive. I suspect that we need to learn more about the role of dark matter to address these questions properly.
– PM 2Ring
49 mins ago
 |Â
show 1 more comment
4
Why do you say that it "must have some insane gravitational pull"? Stuff orbits the barycenter because it's the center of mass, it doesn't have to be a big concentration of mass. FWIW, for galaxies with a central BH, the mass of that BH is a tiny fraction of the whole galaxy's mass. It's not like the BH dominates the galaxy's gravitational structure, although of course it has a fairly big effect in the immediate vicinity of the BH.
– PM 2Ring
13 hours ago
2
Where's the black hole in the middle of every binary system that makes the stars orbit the barycenter? The mass of the stars is more than enough, you don't need them to orbit something else. Solve for a binary star system, and you'll see the same mechanism still works for n-bodies.
– Luaan
6 hours ago
@PM2Ring: While that's a fairly well-known physical result, it ignores the fundamental question: Would all that mass even be there concentrated in a galaxy without a black hole? Or are black holes essential to the formation of starts and their clustering into a galaxy?
– MSalters
1 hour ago
@Luaan If the mass of the stars is more than enough, does that mean that they will collide/merge?
– Andrew Morton
1 hour ago
@MSalters Sure, central black holes might be important in galaxy formation, but I don't see how they are relevant to star formation. And then you have to explain spiral galaxies without a central BH. Did they lose their BH, eg in a collision? If so, how did they manage to retain their spiral structure? FWIW, we still don't have a good theory to explain how super massive BHs are so massive. I suspect that we need to learn more about the role of dark matter to address these questions properly.
– PM 2Ring
49 mins ago
4
4
Why do you say that it "must have some insane gravitational pull"? Stuff orbits the barycenter because it's the center of mass, it doesn't have to be a big concentration of mass. FWIW, for galaxies with a central BH, the mass of that BH is a tiny fraction of the whole galaxy's mass. It's not like the BH dominates the galaxy's gravitational structure, although of course it has a fairly big effect in the immediate vicinity of the BH.
– PM 2Ring
13 hours ago
Why do you say that it "must have some insane gravitational pull"? Stuff orbits the barycenter because it's the center of mass, it doesn't have to be a big concentration of mass. FWIW, for galaxies with a central BH, the mass of that BH is a tiny fraction of the whole galaxy's mass. It's not like the BH dominates the galaxy's gravitational structure, although of course it has a fairly big effect in the immediate vicinity of the BH.
– PM 2Ring
13 hours ago
2
2
Where's the black hole in the middle of every binary system that makes the stars orbit the barycenter? The mass of the stars is more than enough, you don't need them to orbit something else. Solve for a binary star system, and you'll see the same mechanism still works for n-bodies.
– Luaan
6 hours ago
Where's the black hole in the middle of every binary system that makes the stars orbit the barycenter? The mass of the stars is more than enough, you don't need them to orbit something else. Solve for a binary star system, and you'll see the same mechanism still works for n-bodies.
– Luaan
6 hours ago
@PM2Ring: While that's a fairly well-known physical result, it ignores the fundamental question: Would all that mass even be there concentrated in a galaxy without a black hole? Or are black holes essential to the formation of starts and their clustering into a galaxy?
– MSalters
1 hour ago
@PM2Ring: While that's a fairly well-known physical result, it ignores the fundamental question: Would all that mass even be there concentrated in a galaxy without a black hole? Or are black holes essential to the formation of starts and their clustering into a galaxy?
– MSalters
1 hour ago
@Luaan If the mass of the stars is more than enough, does that mean that they will collide/merge?
– Andrew Morton
1 hour ago
@Luaan If the mass of the stars is more than enough, does that mean that they will collide/merge?
– Andrew Morton
1 hour ago
@MSalters Sure, central black holes might be important in galaxy formation, but I don't see how they are relevant to star formation. And then you have to explain spiral galaxies without a central BH. Did they lose their BH, eg in a collision? If so, how did they manage to retain their spiral structure? FWIW, we still don't have a good theory to explain how super massive BHs are so massive. I suspect that we need to learn more about the role of dark matter to address these questions properly.
– PM 2Ring
49 mins ago
@MSalters Sure, central black holes might be important in galaxy formation, but I don't see how they are relevant to star formation. And then you have to explain spiral galaxies without a central BH. Did they lose their BH, eg in a collision? If so, how did they manage to retain their spiral structure? FWIW, we still don't have a good theory to explain how super massive BHs are so massive. I suspect that we need to learn more about the role of dark matter to address these questions properly.
– PM 2Ring
49 mins ago
 |Â
show 1 more comment
1 Answer
1
active
oldest
votes
up vote
9
down vote
accepted
It's generally assumed that most galaxies have a black hole at their centre. There are galaxies we've detected that don't seem to have a black hole though, so it's not a necessary requirement or a guaranteed find in every case.
In cases without a black hole, it has been postulated that the gravity of the stars and gases combined is enough to hold the galaxy together.
answered 16 hours ago
Kyle
2366
3
Even in galaxies withy central black holes, the gravity of the stars and gas (and dark matter) is enough to hold it together; the black hole is almost always a very small fraction of the total. (E.g., the Milky Way's central black hole is about one ten-thousandth of the combined mass of the Milky Way's stars.)
– Peter Erwin
6 hours ago
4
Some references would be nice.
– pela
5 hours ago
Abell 2261
– Dhruv Saxena
4 hours ago
1
Upper limit of 1500 solar masses on any possible BH at center of M33: iopscience.iop.org/article/10.1086/323481/meta
– Peter Erwin
2 hours ago
1
You'd think a black-hole-less galaxy would be roughly as rare as a starless planetary system (of our solar-system's mass). Yeah, there's probably some out there, but gravity + the occasional collision + enough time, and enough of the system is bound to makes its way to the center of mass.
– T.E.D.
1 hour ago
 |Â
show 2 more comments
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
9
down vote
accepted
It's generally assumed that most galaxies have a black hole at their centre. There are galaxies we've detected that don't seem to have a black hole though, so it's not a necessary requirement or a guaranteed find in every case.
In cases without a black hole, it has been postulated that the gravity of the stars and gases combined is enough to hold the galaxy together.
answered 16 hours ago
Kyle
2366
3
Even in galaxies withy central black holes, the gravity of the stars and gas (and dark matter) is enough to hold it together; the black hole is almost always a very small fraction of the total. (E.g., the Milky Way's central black hole is about one ten-thousandth of the combined mass of the Milky Way's stars.)
– Peter Erwin
6 hours ago
4
Some references would be nice.
– pela
5 hours ago
Abell 2261
– Dhruv Saxena
4 hours ago
1
Upper limit of 1500 solar masses on any possible BH at center of M33: iopscience.iop.org/article/10.1086/323481/meta
– Peter Erwin
2 hours ago
1
You'd think a black-hole-less galaxy would be roughly as rare as a starless planetary system (of our solar-system's mass). Yeah, there's probably some out there, but gravity + the occasional collision + enough time, and enough of the system is bound to makes its way to the center of mass.
– T.E.D.
1 hour ago
 |Â
show 2 more comments
up vote
9
down vote
accepted
It's generally assumed that most galaxies have a black hole at their centre. There are galaxies we've detected that don't seem to have a black hole though, so it's not a necessary requirement or a guaranteed find in every case.
In cases without a black hole, it has been postulated that the gravity of the stars and gases combined is enough to hold the galaxy together.
answered 16 hours ago
Kyle
2366
3
Even in galaxies withy central black holes, the gravity of the stars and gas (and dark matter) is enough to hold it together; the black hole is almost always a very small fraction of the total. (E.g., the Milky Way's central black hole is about one ten-thousandth of the combined mass of the Milky Way's stars.)
– Peter Erwin
6 hours ago
4
Some references would be nice.
– pela
5 hours ago
Abell 2261
– Dhruv Saxena
4 hours ago
1
Upper limit of 1500 solar masses on any possible BH at center of M33: iopscience.iop.org/article/10.1086/323481/meta
– Peter Erwin
2 hours ago
1
You'd think a black-hole-less galaxy would be roughly as rare as a starless planetary system (of our solar-system's mass). Yeah, there's probably some out there, but gravity + the occasional collision + enough time, and enough of the system is bound to makes its way to the center of mass.
– T.E.D.
1 hour ago
 |Â
show 2 more comments
up vote
9
down vote
accepted
up vote
9
down vote
accepted
It's generally assumed that most galaxies have a black hole at their centre. There are galaxies we've detected that don't seem to have a black hole though, so it's not a necessary requirement or a guaranteed find in every case.
In cases without a black hole, it has been postulated that the gravity of the stars and gases combined is enough to hold the galaxy together.
answered 16 hours ago
Kyle
2366
It's generally assumed that most galaxies have a black hole at their centre. There are galaxies we've detected that don't seem to have a black hole though, so it's not a necessary requirement or a guaranteed find in every case.
In cases without a black hole, it has been postulated that the gravity of the stars and gases combined is enough to hold the galaxy together.
answered 16 hours ago
Kyle
2366
answered 16 hours ago
Kyle
2366
answered 16 hours ago
Kyle
2366
answered 16 hours ago
Kyle
2366
2366
3
Even in galaxies withy central black holes, the gravity of the stars and gas (and dark matter) is enough to hold it together; the black hole is almost always a very small fraction of the total. (E.g., the Milky Way's central black hole is about one ten-thousandth of the combined mass of the Milky Way's stars.)
– Peter Erwin
6 hours ago
4
Some references would be nice.
– pela
5 hours ago
Abell 2261
– Dhruv Saxena
4 hours ago
1
Upper limit of 1500 solar masses on any possible BH at center of M33: iopscience.iop.org/article/10.1086/323481/meta
– Peter Erwin
2 hours ago
1
You'd think a black-hole-less galaxy would be roughly as rare as a starless planetary system (of our solar-system's mass). Yeah, there's probably some out there, but gravity + the occasional collision + enough time, and enough of the system is bound to makes its way to the center of mass.
– T.E.D.
1 hour ago
 |Â
show 2 more comments
3
Even in galaxies withy central black holes, the gravity of the stars and gas (and dark matter) is enough to hold it together; the black hole is almost always a very small fraction of the total. (E.g., the Milky Way's central black hole is about one ten-thousandth of the combined mass of the Milky Way's stars.)
– Peter Erwin
6 hours ago
4
Some references would be nice.
– pela
5 hours ago
Abell 2261
– Dhruv Saxena
4 hours ago
1
Upper limit of 1500 solar masses on any possible BH at center of M33: iopscience.iop.org/article/10.1086/323481/meta
– Peter Erwin
2 hours ago
1
You'd think a black-hole-less galaxy would be roughly as rare as a starless planetary system (of our solar-system's mass). Yeah, there's probably some out there, but gravity + the occasional collision + enough time, and enough of the system is bound to makes its way to the center of mass.
– T.E.D.
1 hour ago
3
3
Even in galaxies withy central black holes, the gravity of the stars and gas (and dark matter) is enough to hold it together; the black hole is almost always a very small fraction of the total. (E.g., the Milky Way's central black hole is about one ten-thousandth of the combined mass of the Milky Way's stars.)
– Peter Erwin
6 hours ago
Even in galaxies withy central black holes, the gravity of the stars and gas (and dark matter) is enough to hold it together; the black hole is almost always a very small fraction of the total. (E.g., the Milky Way's central black hole is about one ten-thousandth of the combined mass of the Milky Way's stars.)
– Peter Erwin
6 hours ago
4
4
Some references would be nice.
– pela
5 hours ago
Some references would be nice.
– pela
5 hours ago
Abell 2261
– Dhruv Saxena
4 hours ago
Abell 2261
– Dhruv Saxena
4 hours ago
1
1
Upper limit of 1500 solar masses on any possible BH at center of M33: iopscience.iop.org/article/10.1086/323481/meta
– Peter Erwin
2 hours ago
Upper limit of 1500 solar masses on any possible BH at center of M33: iopscience.iop.org/article/10.1086/323481/meta
– Peter Erwin
2 hours ago
1
1
You'd think a black-hole-less galaxy would be roughly as rare as a starless planetary system (of our solar-system's mass). Yeah, there's probably some out there, but gravity + the occasional collision + enough time, and enough of the system is bound to makes its way to the center of mass.
– T.E.D.
1 hour ago
You'd think a black-hole-less galaxy would be roughly as rare as a starless planetary system (of our solar-system's mass). Yeah, there's probably some out there, but gravity + the occasional collision + enough time, and enough of the system is bound to makes its way to the center of mass.
– T.E.D.
1 hour ago
 |Â
show 2 more comments
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4
Why do you say that it "must have some insane gravitational pull"? Stuff orbits the barycenter because it's the center of mass, it doesn't have to be a big concentration of mass. FWIW, for galaxies with a central BH, the mass of that BH is a tiny fraction of the whole galaxy's mass. It's not like the BH dominates the galaxy's gravitational structure, although of course it has a fairly big effect in the immediate vicinity of the BH.
– PM 2Ring
13 hours ago
2
Where's the black hole in the middle of every binary system that makes the stars orbit the barycenter? The mass of the stars is more than enough, you don't need them to orbit something else. Solve for a binary star system, and you'll see the same mechanism still works for n-bodies.
– Luaan
6 hours ago
@PM2Ring: While that's a fairly well-known physical result, it ignores the fundamental question: Would all that mass even be there concentrated in a galaxy without a black hole? Or are black holes essential to the formation of starts and their clustering into a galaxy?
– MSalters
1 hour ago
@Luaan If the mass of the stars is more than enough, does that mean that they will collide/merge?
– Andrew Morton
1 hour ago
@MSalters Sure, central black holes might be important in galaxy formation, but I don't see how they are relevant to star formation. And then you have to explain spiral galaxies without a central BH. Did they lose their BH, eg in a collision? If so, how did they manage to retain their spiral structure? FWIW, we still don't have a good theory to explain how super massive BHs are so massive. I suspect that we need to learn more about the role of dark matter to address these questions properly.
– PM 2Ring
49 mins ago