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View Full Version : At what distance from us (centre of Milky Way) is MES > gravity?



AndrewJ
2008-Dec-08, 06:22 PM
At what distance from us (centre of Milky Way) does expanding space typically overcome intergalactic gravitational attraction?

- At the fringe of our Local Group?

- The edge of the "Local Volume"? (I understand that, for instance, M81 group could interact gravitationally with our Local Group although there is a trend to recession from us.)

- The edge of our Local (Virgo) Supercluster?

Andrew
Edmonton, AB, Canada

seanhogge
2008-Dec-08, 06:26 PM
Since you stated intergalactic gravitational attraction, I assume we're speaking only of galactic formations or objects/constructs of similar scale.

However, I believe it would be dependent on the mass of the body in question. There won't be a definitive horizon, which seems to be what you're looking for.

Others can expound more technically and specifically if I'm not incorrect.

AndrewJ
2008-Dec-08, 08:55 PM
However, I believe it would be dependent on the mass of the body in question. There won't be a definitive horizon, which seems to be what you're looking for.


Granted, mass of object would determine gravitational attraction, therefore there cannot be a determined horizon in space beyond which recession from us is inevitable.

However:
1) Galaxies within the Local Group are seemingly not receding from each other.
2) More distant galaxies up to and including the M81 group can interact with our Local Group but may also be receding.
3) Galaxies that are further away still, such as in the M101 group or Virgo cluster, seem to be receding from us.

From our perspective, are objects further distant than the M81 group more likely than not to be receding from us?