The AGN–Star Formation Connection: Future Prospects with JWST

• Main Authors: Kirkpatrick, Allison, Alberts, Stacey, Pope, Alexandra, Barro, Guillermo, Bonato, Matteo, Kocevski, Dale D., Pérez-González, Pablo, Rieke, George H., Rodríguez-Muñoz, Lucia, Sajina, Anna, Grogin, Norman A., Mantha, Kameswara Bharadwaj, Pandya, Viraj, Pforr, Janine, Salvato, Mara, Santini, Paola
• Other Authors: Univ Arizona, Steward Observ
• Language: en
• Published: IOP PUBLISHING LTD 2017
• Subjects: galaxies: active; galaxies: photometry; galaxies: star formation
• Online Access: http://hdl.handle.net/10150/626176; http://arizona.openrepository.com/arizona/handle/10150/626176

The bulk of the stellar growth over cosmic time is dominated by IR-luminous galaxies at cosmic noon (z = 1-2), many of which harbor a hidden active galactic nucleus (AGN). We use state-of-the-art infrared color diagnostics, combining Spitzer and Herschel observations, to separate dust-obscured AGNs from dusty star-forming galaxies (SFGs) in the CANDELS and COSMOS surveys. We calculate 24 mu m counts of SFGs, AGN/star-forming "Composites," and AGNs. AGNs and Composites dominate the counts above 0.8 mJy at 24 mu m, and Composites form at least 25% of an IR sample even to faint detection limits. We develop methods to use the Mid-Infrared Instrument (MIRI) on JWST to identify dust-obscured AGNs and Composite galaxies from z similar to 1-2. With the sensitivity and spacing of MIRI filters, we will detect >4 times as many AGN hosts as with Spitzer/IRAC criteria. Any star formation rates based on the 7.7 mu m PAH feature (likely to be applied to MIRI photometry) must be corrected for the contribution of the AGN, or the star formation rate will be overestimated by similar to 35% for cases where the AGN provides half the IR luminosity and similar to 50% when the AGN accounts for 90% of the luminosity. Finally, we demonstrate that our MIRI color technique can select AGNs with an Eddington ratio of lambda(Edd) similar to 0.01 and will identify AGN hosts with a higher specific star formation rate than X-ray techniques alone. JWST/MIRI will enable critical steps forward in identifying and understanding dust-obscured AGNs and the link to their host galaxies.