Effects of ultra-fast outflows on X-ray time lags in AGN

Fuente: arXiv
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Autori principali: Xu, Yerong, Pinto, Ciro, Kara, Erin, Bianchi, Stefano, Alston, William, Tombesi, Francesco
Natura: Preprint
Pubblicazione: 2024
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author Xu, Yerong
Pinto, Ciro
Kara, Erin
Bianchi, Stefano
Alston, William
Tombesi, Francesco
author_facet Xu, Yerong
Pinto, Ciro
Kara, Erin
Bianchi, Stefano
Alston, William
Tombesi, Francesco
contents The time lag between soft and hard X-ray photons has been observed in many active galactic nuclei (AGN) and can reveal the accretion process and geometry around supermassive black holes (SMBHs). High-frequency Fe K and soft lags are considered to originate from the light-travel distances between the corona and the accretion disk, while the propagation of the inward mass accretion fluctuation usually explains the low-frequency hard lags. Ultra-fast outflows (UFOs), with a velocity range of 0.03-0.3c, have also been discovered in numerous AGN and are believed to be launched from the inner accretion disk. However, it remains unclear whether UFOs can affect the X-ray time lags. As a pilot work, we aim to investigate the potential influence of UFOs on X-ray time lags of AGN in a small sample. By performing the UFO-resolved Fourier spectral timing analysis of archival XMM-Newton observations of three AGN with transient UFOs: PG 1448+273, IRAS 13224-3809, and PG 1211+143, we compare their X-ray timing products, such as lag-frequency and lag-energy spectra, of observations with and without UFO obscuration. Our results find that in each AGN, low-frequency hard lags become weak or even disappear when they are accompanied by UFOs. In the high-frequency domain, soft lags remain unchanged while the Fe K reverberation lags tentatively disappear. The comparison between timing products of low- and high-flux observations on another three AGN without UFOs (Ark 564, NGC 7469, and Mrk 335) suggests that the disappearance of low-frequency hard lags is likely related to the emergence of UFOs, not necessarily related to the source flux. We conclude that the presence of UFOs can affect X-ray time lags of AGN by suppressing the low-frequency hard lags, which can be explained by an additional time delay introduced by UFOs or disk accretion energy carried away by UFOs.
format Preprint
id arxiv_https___arxiv_org_abs_2411_02736
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Effects of ultra-fast outflows on X-ray time lags in AGN
Xu, Yerong
Pinto, Ciro
Kara, Erin
Bianchi, Stefano
Alston, William
Tombesi, Francesco
High Energy Astrophysical Phenomena
The time lag between soft and hard X-ray photons has been observed in many active galactic nuclei (AGN) and can reveal the accretion process and geometry around supermassive black holes (SMBHs). High-frequency Fe K and soft lags are considered to originate from the light-travel distances between the corona and the accretion disk, while the propagation of the inward mass accretion fluctuation usually explains the low-frequency hard lags. Ultra-fast outflows (UFOs), with a velocity range of 0.03-0.3c, have also been discovered in numerous AGN and are believed to be launched from the inner accretion disk. However, it remains unclear whether UFOs can affect the X-ray time lags. As a pilot work, we aim to investigate the potential influence of UFOs on X-ray time lags of AGN in a small sample. By performing the UFO-resolved Fourier spectral timing analysis of archival XMM-Newton observations of three AGN with transient UFOs: PG 1448+273, IRAS 13224-3809, and PG 1211+143, we compare their X-ray timing products, such as lag-frequency and lag-energy spectra, of observations with and without UFO obscuration. Our results find that in each AGN, low-frequency hard lags become weak or even disappear when they are accompanied by UFOs. In the high-frequency domain, soft lags remain unchanged while the Fe K reverberation lags tentatively disappear. The comparison between timing products of low- and high-flux observations on another three AGN without UFOs (Ark 564, NGC 7469, and Mrk 335) suggests that the disappearance of low-frequency hard lags is likely related to the emergence of UFOs, not necessarily related to the source flux. We conclude that the presence of UFOs can affect X-ray time lags of AGN by suppressing the low-frequency hard lags, which can be explained by an additional time delay introduced by UFOs or disk accretion energy carried away by UFOs.
title Effects of ultra-fast outflows on X-ray time lags in AGN
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2411.02736