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Arxiv: The Case for Super-Eddington Accretion: Connecting Weak X-ray and UV Line Emission in JWST Broad-Line AGN During the First Gyr of Cosmic Time Published: 9/19/2024 9:42:46 PM Updated: 9/19/2024 9:42:46 PM

Paper abstract: A multitude of JWST studies reveal a surprising over-abundance ofover-massive accreting super-massive blackholes (SMBHs) -- leading to adeepening tension between theory and observation in the first billion years ofcosmic time. Across X-ray to infrared wavelengths, models built off of pre-JWSTpredictions fail to easily reproduce observed AGN signatures (or lack thereof),driving uncertainty around the true nature of these sources. Using a sample ofJWST AGN identified via their broadened Halpha emission and covered by thedeepest X-ray surveys, we find neither any measurable X-ray emission nor anydetection of high-ionization emission lines frequently associated withaccreting SMBHs. We propose that these sources are accreting at or beyond theEddington limit, which reduces the need for efficient production of heavy SMBHseeds at cosmic dawn. Using a theoretical model of super-Eddington accretion,we can produce the observed relative dearth of both X-ray and ultravioletemission, as well as the high Balmer decrements, without the need forsignificant dust attenuation. This work indicates that super-Eddingtonaccretion is easily achieved through-out the early Universe, and further studyis required to determine what environments are required to trigger this mode ofblack hole growth.