The WISSH quasars project XIII. A multi-epoch study of ultra-fast broad absorption line outflows at cosmic noon
Abstract
Ultra-fast broad absorption line outflows (uBAL, ~0.1-0.2c) represent some of the most extreme manifestations of quasar-driven winds. We aim to investigate the variability of uBALs through their characterisation across different epochs and multiple ionic species. The main goal is to constrain their physical properties, locations, and kinetic powers to evaluate their potential impact on the respective quasar host galaxies. We performed a multi-epoch analysis of three hyper-luminous quasars from the WISSH sample, namely WISSH53, WISSH56, and WISSH71, at redshifts z=3.628, 4.101, and 3.567, respectively. New and archival spectra, spanning up to ~23 years of monitoring in the observed frame, were used in the analysis. We modeled absorption associated with the CIV transition with Gaussian components, accounting for covering factor variations. A conservative analysis of multi-ion profiles (PV, Lyalpha, NV, SiIV) was also performed, considering the same uBAL velocity as CIV. We derived ionic column density, as well as ionisation parameters, which allowed us to estimate lower and upper limits on distances and kinetic powers of the outflows. The CIV uBALs in the three sources exhibit velocities up to ~0.2c and show significant variability across epochs, likely driven by changes in ionisation state and/or transverse gas motion. The analysis of the multiple troughs highlights the dominant mechanisms causing variability and enables the derivation of robust lower and upper limits of the physical and energetic properties of the outflows. Outflow distances are constrained from the broad line region (BLR) radius (~1 pc) up to a few hundred parsecs, and kinetic powers of individual troughs reach up to ~25% of the quasar bolometric luminosity, in the most extreme cases. Our results demonstrate that extreme outflows such as the uBALs are able to inject sufficient kinetic energy to affect the host medium.
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BibTeX
@misc{decontomachado2026wissh,
title = {{The WISSH quasars project XIII. A multi-epoch study of ultra-fast broad absorption line outflows at cosmic noon}},
author = {A. Deconto-Machado and G. Vietri and E. Piconcelli and S. Bisogni and T. Misawa and A. Gargiulo and G. Lanzuisi and A. Travascio and M. Bischetti and L. Zappacosta and E. Bertola and G. Cresci and F. la Franca and M. Gaspari and F. Salvestrini and C. Vignali and A. Luminari and E. Marini and F. Tombesi and A. Bongiorno and S. Carniani and C. Feruglio and F. Fiore and E. Glikman and V. Testa},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.15275},
eprint = {2609.15275},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.15275},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - The WISSH quasars project XIII. A multi-epoch study of ultra-fast broad absorption line outflows at cosmic noon
AU - A. Deconto-Machado
AU - G. Vietri
AU - E. Piconcelli
AU - S. Bisogni
AU - T. Misawa
AU - A. Gargiulo
AU - G. Lanzuisi
AU - A. Travascio
AU - M. Bischetti
AU - L. Zappacosta
AU - E. Bertola
AU - G. Cresci
AU - F. la Franca
AU - M. Gaspari
AU - F. Salvestrini
AU - C. Vignali
AU - A. Luminari
AU - E. Marini
AU - F. Tombesi
AU - A. Bongiorno
AU - S. Carniani
AU - C. Feruglio
AU - F. Fiore
AU - E. Glikman
AU - V. Testa
PY - 2026
DA - 2026/09/14
PB - arXiv
DO - 10.48550/arxiv.2609.15275
UR - https://arxiv.org/abs/2609.15275
AB - Ultra-fast broad absorption line outflows (uBAL, ~0.1-0.2c) represent some of the most extreme manifestations of quasar-driven winds. We aim to investigate the variability of uBALs through their characterisation across different epochs and multiple ionic species. The main goal is to constrain their physical properties, locations, and kinetic powers to evaluate their potential impact on the respective quasar host galaxies. We performed a multi-epoch analysis of three hyper-luminous quasars from the WISSH sample, namely WISSH53, WISSH56, and WISSH71, at redshifts z=3.628, 4.101, and 3.567, respectively. New and archival spectra, spanning up to ~23 years of monitoring in the observed frame, were used in the analysis. We modeled absorption associated with the CIV transition with Gaussian components, accounting for covering factor variations. A conservative analysis of multi-ion profiles (PV, Lyalpha, NV, SiIV) was also performed, considering the same uBAL velocity as CIV. We derived ionic column density, as well as ionisation parameters, which allowed us to estimate lower and upper limits on distances and kinetic powers of the outflows. The CIV uBALs in the three sources exhibit velocities up to ~0.2c and show significant variability across epochs, likely driven by changes in ionisation state and/or transverse gas motion. The analysis of the multiple troughs highlights the dominant mechanisms causing variability and enables the derivation of robust lower and upper limits of the physical and energetic properties of the outflows. Outflow distances are constrained from the broad line region (BLR) radius (~1 pc) up to a few hundred parsecs, and kinetic powers of individual troughs reach up to ~25% of the quasar bolometric luminosity, in the most extreme cases. Our results demonstrate that extreme outflows such as the uBALs are able to inject sufficient kinetic energy to affect the host medium.
ER -