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Astronomy Colloquium - "Toward a "Complete Census of AGN at Cosmic Noon: Ultra-deep X-ray, Radio, and (coming soon!) JWST"

Event Type
Department of Astronomy
wifi event
Apr 20, 2021   3:45 pm  
Dr. Stacey Alberts, University of Arizona
Rebecca Bare
Originating Calendar
Astronomy Colloquium Speaker Calendar

The challenges in overcoming the selection biases inherent in AGN selection techniques - and the challenge of identifying heavily obscured and Compton Thick AGN at all - have long hindered our global understanding of AGN and their hosts. In this talk, I will present our first step toward a complete census of AGN in the GOODS-S/HUDF region at cosmic noon (z~1-3). Using new, ultra-deep, high resolution radio imaging at 3 and 6 GHz, we identify AGN in a population of faint star forming galaxies by minimizing selection bias through multiple techniques: X-ray properties via the unique 7 Ms Chandra imaging; mid-IR colors and SED fitting via extensive 3D-HST photometry; and radio properties such as radio excess or a flat radio spectrum. The AGN counts - fully half of our sub-microJy radio sources have evidence for an AGN - and properties from this sample inform future AGN surveys. Likely still missing from this census are the most heavily obscured AGN at cosmic noon, which we argue will be best revealed through their mid-infrared properties via the wavelength coverage of JWST/MIRI. In closing, I will present our Cycle 1 GTO MIRI imaging and NIRSpec spectroscopy program aimed at completing our census.

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