by astro_uk » Mon Sep 04, 2006 4:50 pm
I don't think that two galaxies collided to form NGC 3718 but from the information available it does seem as if it has been tidally disrupted by the other spiral nearby. This type of thing is fairly common, even if the galaxies dont physically hit their gravity can cause damage in each other from a fairly large distance. The Milky Way is tearing apart one of its own dwarf satellite galaxies as we speak.
Check out here for a lot more example of interacting galaxies.
http://www.astr.ua.edu/pairs2.html
This APOD shows a nice example of what happens when two galaxies do actually impact. (in reality the stars in each galaxy just pass each other, but the gravity still screws up the spiral structure)
http://apod.nasa.gov/apod/ap970224.html
Of course if they impact more slowly and are gravitationally bound they tend to merge to form large elliptical galaxies.
I don't think that two galaxies collided to form NGC 3718 but from the information available it does seem as if it has been tidally disrupted by the other spiral nearby. This type of thing is fairly common, even if the galaxies dont physically hit their gravity can cause damage in each other from a fairly large distance. The Milky Way is tearing apart one of its own dwarf satellite galaxies as we speak.
Check out here for a lot more example of interacting galaxies.
http://www.astr.ua.edu/pairs2.html
This APOD shows a nice example of what happens when two galaxies do actually impact. (in reality the stars in each galaxy just pass each other, but the gravity still screws up the spiral structure)
http://apod.nasa.gov/apod/ap970224.html
Of course if they impact more slowly and are gravitationally bound they tend to merge to form large elliptical galaxies.