What does dex mean in black hole mass measurements?

[Chronos000]

Homework Statement

I've been reading various journal articles about black hole masses. The values given there are given by X +/- Y dex. I cannot find any literature on "dex" nor do the articles go into detail as it is evidently a basic concept that I've just never come across.

Could someone enlighten me?

 

[jedishrfu]

from this website I got the definition of dex as:

dex
a logarithmic unit being used in astronomy. Originally, dex was a convenient function defined by dex (x) = 10x. But the notation is now being used after the exponent in expressions such as -.043 dex, meaning 10-.043. Thus 1 dex equals a factor of 10, making the dex identical to the bel. The name "dex" is a contraction of "decimal exponent."

http://www.unc.edu/~rowlett/units/dictD.html