Context

Quasars, the most luminous type of active galactic nuclei (AGN), are believed to be powered by accreting supermassive black holes (SMBHs). The continuum and line emissions from luminous quasars, over a large wavelength range, from optical-infrared to X-ray, carry crucial insights into the accrection and growth of the central SMBHs. We are performing a Chandra X-ray survey of the first uniform and complete sample of luminous quasars at z>6.5. Together with quasar luminosity function and black hole mass function that we are measuring from deep optical-to-infrared observations, the Chandra X-ray observations will provide key constraints to the formation and growth history of the earliest SMBHs. Our Chandra programs, combined with the infrared spectroscopy of a larger sample will allow us to carry out the first statistical measurement of X-ray properties of z>6.5 quasars, to probe the evolution of X-ray slope, spectral energy distribution and accretion rate of early quasars. See Wang+2021 for more details about our Cycle 19 observations.

Science Goals

• Evolution of quasar X-ray spectral shape, broad-band SED, and accretion rate.
• X-ray properties of a diverse quasar population.
• The environment of the most overdense structure traced by quasars.
• Legacy deep fields with multi-wavelegnth coverage (X-ray, optical, infrared, sub-mm and radio).

Observations

• In cycle 19, we were awared 130ks (ID:19700283) for observing five brightest z > 6.5 quasars
• In cycle 22, we were awared 710ks (ID:22700552) for observing seven z ~ 7 quasars
• In cycle 23, we were awared 900ks (ID:23700397) for obtaining a deep exposure for a protocluster anchored by a z~6.6 quasar
• All the targets will be observed with JWST, ALMA and other ground-based telesccopes

Targets