Revising Galaxy Mass Estimation Techniques

[michaelmozina]

http://www.sciencedaily.com/releases/20 ... 145846.htm

The effects are particularly important in parts of the universe where stars are spread out over a larger volume -- the rural Africa of the cosmos. There could be about four times as many stars in these regions than previously estimated.

"Especially in these galaxies that seem small and piddling, there can be a lot more mass in lower mass stars than we had previously expected from what we could see from the brightest, youngest stars," Meurer said. "But we can now reduce these errors using satellites like the Galaxy Evolution Explorer."

It seems like this revelation might go a long way in reducing the need for 'dark matter'.

 

[ramparts]

Well, no, this sort of thing wouldn't do much to kill the dark matter hypothesis. There are still too many data that are best explained by dark matter - though we may not like the idea of it, it's worked incredibly well. (I was at a dark matter conference recently, about three months after this paper was published, and I can tell you no one was too worried )

But this result is really interesting. I hadn't seen it before - thanks for the link!

One thing to keep in mind is this - since the result shows we may be underestimating the number of low-mass stars, the unaccounted stars are all things which will barely add anything to a galaxy's total mass. So in fact, this isn't going to really force us to revise many galaxies' mass estimates, simply because (in this case) even a lot of little things don't compare to a few big things!

 

[michaelmozina]

Well, no, this sort of thing wouldn't do much to kill the dark matter hypothesis.

FYI, I intentionally used the term 'reducing the need' rather than "kill'.