Star formation in far-IR AGN and non-AGN galaxies in the green valley. II. Morphological analysis

DOI: 
10.1093/mnras/stz434
Publication date: 
01/02/2019
Main author: 
Mahoro, Antoine
IAA authors: 
Pović, Mirjana
Authors: 
Mahoro, Antoine;Pović, Mirjana;Nkundabakura, Pheneas;Nyiransengiyumva, Beatrice;Väisänen, Petri
Journal: 
Monthly Notices of the Royal Astronomical Society
Refereed: 
Yes
Publication type: 
Article
Pages: 
452-463
Abstract: 
This paper studies morphological properties of 103 green valley FIR active and 2609 non-active galaxies presented in Mahoro et al. (2017). The photometric data from the COSMOS survey were used, and the morphological parameters, such as Abraham and Conselice-Bershady concentration indices, Gini, M20 moment of light, and asymmetry, were analysed taking into account public catalogues. Furthermore, a visual classification of galaxies was performed. We found that the fraction of peculiar galaxies with clear signs of interactions and mergers is significantly higher in AGN (38%) than non-AGN (19%) green valley galaxies, while non-AGN galaxies from our sample are predominantly spirals (46%). We found that the largest fraction of our green valley galaxies is located on the main-sequence (MS) of star formation, independently on morphology, which is in contrast with most of previous studies carried out in optical. We also found that FIR AGN green valley galaxies have significantly higher star formation rates in all analysed morphological types. Therefore, our results suggest that interactions and mergers obtained in the high fraction of FIR AGN contribute significantly to high star formation rates observed in the selected sample, but are not the only mechanism responsible for enhancing star formation, and others such as AGN positive feedback could contribute as well. In future we will study in more details the possibility of AGN positive feedback through the spectroscopic analysis of public and our SALT data.
Database: 
ADS
SCOPUS
URL: 
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85072261948&doi=10.1093%2fmnras%2fstz434&partnerID=40&md5=dee74642eeac7911807467b656dabea5
ADS Bibcode: 
2019MNRAS.485..452M
Keywords: 
galaxies: active;galaxies: evolution;g-alaxies: star formation;infrared: galaxies;galaxies: high-redshift;galaxies: structure;Astrophysics - Astrophysics of Galaxies