AGN obscuration, Eddington ratio distributions, and clustering: Deep and wide X-ray surveys with NuSTAR and Chandra in the UKIDSS-UDS and Boötes fields

X-ray surveys represent one of the most efficient methods to detect active galactic nuclei (AGN) and perform statistically powerful population studies. In the past decade, important results on AGN evolution have came from both wide and deep X-ray surveys of the sky performed by Chandra and XMM-Newton. The launch of NuSTAR in 2012 allowed to extend such sensitive surveys to higher energies, starting a fruitful synergy between hard and soft X-rays. On one hand, recent deep hard X-ray surveys confirmed the presence of a population of heavily obscured AGN: We will begin by present the results of a deep NuSTAR survey of the UKIDSS-UDS field, as well as the aggregated results in the COSMOS, ECDFS and UDS fields obtained exploiting three new hard NuSTAR bands. We will highlight an interesting source in the COSMOS field that is barely detected by Chandra due to heavy obscuration, but clearly stands out in the NuSTAR 8-16 keV band. We will then present the present status and future perspectives of the new Chandra survey in the central 6 deg² of the Bootes field (the Chandra Deep Wide Field Survey, CDWFS). The CDWFS X-ray catalog contains more than 7,500 sources when combining three Chandra bands. We will give an overview of future studies of the large-scale clustering of AGN and their Eddington-ratio distribution that will benefit from the exquisite Chandra angular resolution and sensitivity on this very large multiwavelength field. This work is supported in part by NASA grant NNX15AP24G and Chandra grant GO7-18130X.