OII emitting galaxies

Around the redshift ranges, z, of galaxies from .5-1.6, how fast does these galaxies convert gas to stars.
A star has gas around it, and the gas is ionized and free electrons are emmitted which is called plasma.
These free electrons collide with oxygen atoms in the gas. When this collision happens electrons in the oxygen atom will move from a higher orbital state to a lower orbital. A photon will be emmited when the electron makes this transaction. The wavelength of this photon is about 3727 angstroms. or 372.7 nm(nanometers).
Astronomers will get a spectrum of galaxies and any galaxy with this wavelength in the spectrum will have a double peak. Now, astronomers will know that it does have oxygen in it, and can use this galaxy in the Schmidt-Kennicutt Law to calculate a star formation rate.
In order to calculate a star formation rate:
You start with the redshift, and find the flux of the galaxy.

From the flux of the galaxy, you can find the luminousity of it.

L(O[II]) = F(O[II]) 4πZ²

From this luminousity  you can calculate a star formation rate.

SFR(M_sunyear^-1) = (1.4 ± 0.4 )x 10^-41 L[OII] (ergs s^-1)

there are other emission lines astronomers look at, but I like OII because its what I work on.!!