Star formation of far-IR AGN and non-AGN galaxies in the green valley: Possible implication of AGN positive feedback

In this paper we present the star formation properties of I ≤ 23 X-ray detected active galactic nucleus (AGN) and non-AGN galaxies in the green valley with far-infrared (FIR) emission, using data from the COSMOS field. We measured star formation rates (SFR) using FIR Herschel/PACS data and we observ...

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Detalhes bibliográficos
Autores: Mahoro, Antoine, Pović, Mirjana, Nkundabakura, Pheneas
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2017
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/376289
Acesso em linha:http://hdl.handle.net/10261/376289
Access Level:Acceso aberto
Palavra-chave:Galaxies: active
Galaxies: evolution
Galaxies: star formation
Infrared: galaxies.
Descrição
Resumo:In this paper we present the star formation properties of I ≤ 23 X-ray detected active galactic nucleus (AGN) and non-AGN galaxies in the green valley with far-infrared (FIR) emission, using data from the COSMOS field. We measured star formation rates (SFR) using FIR Herschel/PACS data and we observed the location of AGN and non-AGN galaxies on the main-sequence of star formation. We went a step further in analysing the importance of AGN in quenching star formation in the green valley, the region proposed to be the transitional phase in galaxy evolution where galaxies are moving from later- to earlier-types.We found that most of our green valley X-ray detected AGNs with FIR emission have SFRs higher than the ones of inactive galaxies at fixed stellar mass ranges, the result that is different when considering optical data. These FIR AGNs have still very active star formation, being located either on or above the main sequence of star formation (in total 82 per cent of our sample). Therefore, they do not show signs of star formation quenching, but rather its enhancement. Our results may suggest that for X-ray detected AGNs with FIR emission if there is an influence of AGN feedback on the star formation in the green valley the scenario of AGN positive feedback seem to take place, rather than the negative one. © 2017 The Authors