Deep ALMA photometry of distant X-ray AGN: improvements in star formation rate constraints, and AGN identification

Stanley, Flora,1990Chalmers tekniska högskola,Chalmers University of Technology (författare)

We present the star formation rates (SFRs) of a sample of 109 galaxies with X-ray selected active galactic nuclei (AGN) with moderate to high X-ray luminosities (L(2-8keV) = 10^42 - 10^45 erg/s), at redshifts 1 < z <4.7, that were selected to be faint or undetected in the Herschel bands. We combine our deep ALMA continuum observations with deblended 8-500um photometry from Spitzer and Herschel , and use infrared (IR) SED fitting and AGN - star formation decomposition methods. The addition of the ALMA photometry results in an order of magnitude more X-ray AGN in our sample with a measured SFR (now 37%). The remaining 63% of the sources have SFR upper limits that are typically a factor of ~2-10 times lower than the pre-ALMA constraints. With the improved constraints on the IR SEDs, we can now identify a mid-IR (MIR) AGN component in 50% of our sample, compared to only ~1% previously. We further explore the F(870um)/F(24um)--redshift plane as a tool for the identification of MIR emitting AGN, for three different samples representing AGN dominated, star formation dominated, and composite sources. We demonstrate that the F(870um)/F(24um)--redshift plane can successfully split between AGN and star formation dominated sources, and can be used as an AGN identification method.

Harrison, C. M.European Southern Observatory (ESO) (författare)
Alexander, D. M.Durham University (författare)
Simpson, J.Academia Sinica Taiwan (författare)
Knudsen, Kirsten Kraiberg,1976Chalmers tekniska högskola,Chalmers University of Technology(Swepub:cth)kraiberg (författare)
Mullaney, J. R.University of Sheffield (författare)
Rosario, D. J.Durham University (författare)
Scholtz, J.Durham University (författare)
Chalmers tekniska högskolaEuropean Southern Observatory (ESO) (creator_code:org_t)

Ingår i:Monthly Notices of the Royal Astronomical Society: Oxford University Press (OUP)478:3, s. 3721-37390035-87111365-2966

Av författaren/redakt...: Stanley, Flora, ...; Harrison, C. M.; Alexander, D. M.; Simpson, J.; Knudsen, Kirsten ...; Mullaney, J. R.; visa fler...; Rosario, D. J.; Scholtz, J.; visa färre...

Om ämnet

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.