Revealing the Accretion Physics of Supermassive Black Holes at Redshift z~7 with Chandra and Infrared Observations

Understand

X-ray emission from quasars has been detected up to redshift $z=7.5$, although only limited to a few objects at $z>6.5$.

• In this work, we present new Chandra observations of five $z>6.5$ quasars.
• By combining with archival Chandra observations of six additional $z>6.5$ quasars, we perform a systematic analysis on the X-ray properties of these earliest accreting supermassive black holes (SMBHs).
• We measure the black hole masses, bolometric luminosities ($L_{\rm bol}$), Eddington ratios ($\lambda_{\rm Edd}$), emission line properties, and infrared luminosities ($L_{\rm IR}$) of these quasars using infrared and sub-millimeter observations.