QSO and close companion galaxy association.

We are carrying out a program to analyze the properties of the close environments of low redshift quasars to investigate the role of the interactions between the AGN and companion galaxies for triggering and fueling the QSO phenomenon. To pursue this aim we secured optical spectra of close (<100 kpc) companion galaxies to the QSO in order to probe their physical association and to search for signature of recent star formation. The observations are collected using the NOT and GTC telescopes at La Palma (Canary Islands). For about half (15 out of 34) of the observed QSO till now we found at least one associated companion galaxy. The associated galaxies show modest SFR (median SFR value similar to a Milky Way type galaxy) based on [O II] emission line luminosity.

For detailed results look at these papers:

Stone B. M. , Bettoni, D. ., Falomo, R.., et al., MNRAS 2020, in press , arXiv:2011.06448

Bettoni, D., Falomo, R., Kotilainen, K. et al. 2017 MNRAS, 466, 3600

Bettoni, D., Falomo, R., Kotilainen, K. et al. 2015, MNRAS, 454, 4103

Falomo, R. Bettoni,D., Karhunen,K, et al 2014 MNRAS 440 476

Karhunen,K, Kotilainen, K., Falomo, R. et al 2014 MNRAS 441 1802