Stellar populations of a sample of far-IR AGN and non-AGN green valley
  galaxies
  We present a study on the stellar populations and stellar ages of sub-sample
of far-infrared AGN and non-AGN green valley analysed in Mahoro et al.
(2017,2019) at 0.6 < z < 1.0 using the data from the COSMOS field. We used
long-slit spectroscopy and derived stellar populations and stellar ages using
the stellar population synthesis code "STARLIGHT" and analysed the available
Lick/IDS indices, such as Dn4000 and $\rm{H\delta_{A}}$. We find that both FIR
AGN and non-AGN green valley galaxies are dominated by intermediate stellar
populations 67 % and 53 %, respectively. The median stellar ages for AGN and
non-AGN are log t = 8.5 [yr] and log t = 8.4 [yr], respectively. We found that
majority of our sources (62 % of AGN and 66 % non-AGN) could have experienced
bursts and continuous star formation. In addition, most of our FIR AGN (38 %)
compared to FIR non-AGN (27 %) might have experienced a burst of SF more than
0.1 Gyr ago. We also found that our FIR AGN and non-AGN green valley galaxies
have similar quenching time-scales of ~ 70 Myr. Therefore, the results obtained
here are in line with our previous results where we do not find that our sample
of FIR AGN in the green valley shows signs of negative AGN feedback, as has
been suggested previously in optical studies.
