2025/11/07 by Villani, I., Zappacosta, L., Piconcelli, E. +17 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · doi:10.48550/arxiv.2511.05036
openalex publication_date 2025/11/07 · openalex created_date 2025/11/11 · openalex updated_date 2026/07/28
The most luminous and obscured quasars (QSOs) detected in infrared all-sky surveys could represent a key co-evolutionary phase from nuclear to circum-galactic (CG) scales in the formation of massive galaxies. In this context, Hot Dust Obscured Galaxies (Hot DOGs) at z ~2-4 provide a unique opportunity to study the link between cosmic mass assembly and nuclear accretion in high-z luminous QSOs/galaxies. W0410-0913 (hereafter W0410-09) is a luminous (\rm ~L\rm bol ∼ 6.4 ×1047 \rm erg s-1) obscured QSO at z = 3.631, with a 30 kpc CG Lyα nebula (CGLAN), smaller than the ~ 100 kpc nebulae around unobscured Type-I QSOs, and an exceptional overdense environment of ~ 19 Lyα emitters (LAEs) within 300 kpc and ± 200 \rm km ~s-1 of the Hot DOG. We aim to detect and characterize nuclear accretion in W0410-09 and its environment. Exploiting a deep proprietary ~280 ks Chandra observation, using empirical and physically motivated models for obscured sources, we show that W0410-09 exhibits Compton-thick obscuration (\rm~ NH > 1024 \rm cm-2) and high intrinsic luminosity (\rm ~L2-10 > 1045 \rm erg ~s-1), making it one of the most luminous obscured QSOs at z > 3.5. With the exclusion of W0410-09 we do not detect X-ray emission from any of the 19 LAEs, except for a 3σ signal in the 6-7 keV rest-frame band, interpreted as Fe Kα emission, suggesting the presence of heavily obscured yet undetected AGN emission in several LAEs. Including W0410-09, the estimated AGN fraction is f\rm AGN\rm LAE = 5+12-4%, potentially up to ~35% if unresolved obscured AGN are considered as suggested by the Fe Kα line detection. We conclude that W0410-09 is in a critical transitional blow-out phase, during which powerful QSO-driven outflows are clearing the nuclear obscuration, ultimately leading to an unobscured luminous quasar.