dark matter related to supermassive black hole?

[gorbe]

I wondered if this idea had already been run through, that Saggitarius a* had an electromagnetic field so immense and powerful that it encompassed the whole galaxy and kept it from flying apart. Yeah, probably what a third grader would say, but I hadn't seen that idea in any forum, just talk that dark matter is an as yet undiscovered particle.

[Spyman]

If the supermassive black hole in the center of our galaxy had such an immense and powerful electromagnetic field that it was a big proportion of holding the Sun in orbit, then shouldn't we be able to measure this magnetic field with our instruments?

 

Also I think that the rotation curves of galaxies imply that the missing force can't be from a centralized source, if Sagittarius A* would be the culprit, then stars closer inwards would have to orbit faster than stars more outward and not almost constant as observed.

 

The rotation curve of a disc galaxy (also called a velocity curve) is the rotational velocity of visible stars or gas in that galaxy as a function of their radial distance from that galaxy's center, typically rendered graphically as a scatter plot of the orbital speed (in km/s) of the stars or gas in the galaxy on the ordinate against the distance from the center of the galaxy on the abscissa.

 

A general feature of the galaxy rotation curves that have been measured is that rotational velocity of stars and gas is constant as far from the galactic centre as can be measured (line B in the illustration): stars are observed to revolve around the centre of these galaxies at a constant speed over a large range of distances from the centre of any galaxy. If disc galaxies had mass distributions similar to the observed distribution of stars and gas, the rotation curves velocities should decline at large distances (dotted line A in illustration) in the same way as do other systems with most of their mass in the centre, such as the Solar System or the moons of Jupiter, following the prediction of Kepler's Laws.

http://en.wikipedia.org/wiki/Galaxy_rotation_curve