We present new narrow-band ( H \alpha and [ O \ @ slowromancap iii @ ] ) imagings and optical spectrophotometry of H \ @ slowromancap ii @ regions for a gas-rich low surface brightness irregular galaxy , KKR 17 .
The central surface brightness of the galaxy is \mu _ { 0 } ( B ) = 24.15 \pm 0.03 mag sec ^ { -2 } .
The galaxy was detected by Arecibo Legacy Fast ALFA survey ( ALFALFA ) , and its mass is dominated by neutral hydrogen ( HI ) gas .
In contrast , both the stellar masses of the bright H \ @ slowromancap ii @ and diffuse stellar regions are small .
In addition , the fit to the spectral energy distribution to each region shows the stellar populations of H \ @ slowromancap ii @ and diffuse regions are different .
The bright H \ @ slowromancap ii @ region contains a large fraction of O-type stars , revealing the recent strong star formation , whereas the diffuse region is dominated by median age stars , which has a typical age of \sim 600 Myrs .
Using the McGaugh ’ s abundance model , we found that the average metallicity of KKR 17 is 12 + ( O/H ) = 8.0 \pm 0.1 .
The star formation rate of KKR 17 is 0.21 \pm 0.04 M _ { \odot } /yr , which is \sim 1/5 of our Milky Way ’ s .
Based on the analysis results to young stellar clusters in H \ @ slowromancap ii @ region , it is found that the bright H \ @ slowromancap ii @ region showed two sub-components with different velocities and metallicities .
This may be caused by the outflow of massive stars or merging events .
However , the mechanism of triggering star formation in the H \ @ slowromancap ii @ region is still uncertain .