Galactic bars: More gravity, more bars

[Dancing David]

http://www.sciencedaily.com/releases/2008/07/080729133527.htm


It might appear that larger galaxies make bars faster and that they are important to the creation of the spiral galaxy form of galaxy.

The astronomers discovered that while spiral galaxies were around in the distant past, only around 20 percent of them possessed the bars that are so common in their modern counterparts. The tripling rate does not proceed in an even-handed way, either. "They are forming mostly in the small, low-mass galaxies," says Sheth, adding that among the most massive galaxies, the proportion of bars to no bars is the same as it is today.

"We know that evolution is generally faster for more massive galaxies--they form their stars early and fast and then fade into red disks," Sheth explains. "Low-mass galaxies were also known to form more slowly, but now we see that they also made their bars slower."

Hey Zeuzzz, BAC...

 

[Wangler]

Don't larger galaxies rotate faster? Would they accumulate more rotations in a given period of time than a lower mass galaxy?

It seems as if some relaxation or dynamical damping is required for bar formation...perhaps the more rotations a galaxy endures, the greater the chance that a bar results?

It seems as if their paper is about the obvious:

Sheth explains. "Low-mass galaxies were also known to form more slowly, but now we see that they also made their bars slower."

 

[Third Eye Open]

The only galactic bar I know of is in the restaurant at the end of the universe.