Herschel far-infrared photometry of the Swift Burst Alert Telescope active galactic nuclei sample of the local universe – III. Global star-forming properties and the lack of a connection to nuclear activity. Issue 3 (15th December 2016)

• Record Type: Journal Article
• Authors: Shimizu, T. Taro; Mushotzky, Richard F.; Meléndez, Marcio; Koss, Michael J.; Barger, Amy J.; Cowie, Lennox L.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 466:Issue 3(2017)
• Page Start: 3161
• Page End: 3183
• Publication Date: 2016-12-15
• Subjects: galaxies: active -- galaxies: evolution -- galaxies: Seyfert -- galaxies: star formation -- infrared: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stw3268
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We combine the Herschel Space Observatory PACS (Photoconductor Array Camera and Spectrometer) and SPIRE (Spectral and Photometric Imaging Receiver) photometry with archival WISE ( Wide-field Infrared Survey Explorer ) photometry to construct the spectral energy distributions (SEDs) for over 300 local ( z < 0.05), ultrahard X-ray (14–195 keV) selected active galactic nuclei (AGN) from the Swift Burst Alert Telescope (BAT) 58-month catalogue. Using a simple analytical model that combines an exponentially cutoff power law with a single temperature modified blackbody, we decompose the SEDs into a host galaxy and AGN component. We calculate dust masses, dust temperatures, and star formation rates (SFRs) for our entire sample and compare them to a stellar mass-matched sample of local non-AGN galaxies. We find AGN host galaxies have systematically higher dust masses, dust temperatures, and SFRs due to the higher prevalence of late-type galaxies to host an AGN, in agreement with previous studies of the Swift /BAT AGN. We provide a scaling to convert X-ray luminosities into 8–1000 μm AGN luminosities, as well as determine the best mid-to-far IR colours for identifying AGN-dominated galaxies in the IR regime. We find that for nearly 30 per cent of our sample, the 70 μm emission contains a significant contribution from the AGN (>0.5), especially at higher luminosities ( L 14 − 195 keV > 10 42.5 erg s −1 ). Finally, we measure the local SFR–AGN luminosity relationship, finding a slope of 0.18, large scatter (0.37 dex), and no evidence for an upturn at high AGN luminosity. We conclude with a discussion on the implications of our results within the context of galaxy evolution with and without AGN feedback.