Hubble Space Telescope observations of BALQSO Ton 34 reveal a connection between the broad-line region and the BAL outflow

Krongold, Y.; Binette, L.; Bohlin, R.; Bianchi, Luciana; Longinotti, A. L.; Mathur, S.; Nicastro, F.; Gupta, Anjali; Negrete, C. A.; Hernández-Ibarra, Francisco J.

doi:10.1093/mnras/stx669

Cited by 4 publications

(2 citation statements)

References 86 publications

(82 reference statements)

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“…There are two major scenarios for the origin of time variability that have often been discussed in the literature: (1) a change of the ionization state of the gas clouds (e.g., Misawa et al 2007b;Hamann et al 2011;Filiz Ak et al 2013;Horiuchi et al 2016) and (2) motion of the absorbing clouds across our line of sight to the background flux source (e.g., Gibson et al 2008;Hamann et al 2008;Vivek et al 2016;Krongold et al 2017). Neither situation is applicable to intervening absorbers, unless they have very large gas density and/or sharp edges (Narayanan et al 2004).…”

Section: Origin Of Time Variabilitymentioning

confidence: 99%

MCMC-based Voigt Profile fitting to a Mini-BAL System in the Quasar UM675

Ishita,

Misawa,

Itoh

et al. 2021

Preprint

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We introduce a Bayesian approach coupled with a Markov Chain Monte Carlo (MCMC) method and the maximum likelihood statistic for fitting the profiles of narrow absorption lines (NALs) in quasar spectra. This method also incorporates overlap between different absorbers. We illustrate and test this method by fitting models to a "mini-broad" (mini-BAL) and six NAL profiles in four spectra of the quasar UM675 taken over a rest-frame interval of 4.24 years. Our fitting results are consistent with past results for the mini-BAL system in this quasar by Hamann et al. (1997b). We also measure covering factors (C f ) for two narrow components in the C IV and N V mini-BALs and their overlap covering factor with the broad component. We find that C f (N V) is always larger than C f (C IV) for the broad component, while the opposite is true for the narrow components in the mini-BAL system. This could be explained if the broad and narrow components originated in gas at different radial distances, but it seems more likely to be due to them produced by gas at the same distance but with different gas densities (i.e., ionization states). The variability detected only in the broad absorption component in the mini-BAL system is probably due to gas motion since both C f (C IV) and C f (N V) vary. We determine for the first time that multiple absorbing clouds (i.e., a broad and two narrow components) overlap along our line of sight. We conclude that the new method improves fitting results considerably compared to previous methods. Subject headings: quasars: absorption lines -quasars: individual (UM675) -methods: data analysis 1 Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

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Section: Origin Of Time Variabilitymentioning

confidence: 99%

MCMC-based Voigt Profile fitting to a Mini-BAL System in the Quasar UM675

Ishita,

Misawa,

Itoh

et al. 2021

Preprint

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“…Several authors further emphasized the role played by turbulence in these winds (e.g., Shields, Ferland, & Peterson 1995;Chelouche & Netzer 2005). In recent years, a clumpy turbulent outflow (CTO) scenario has increasingly been used to interpret observations of obscuring outflows (Kaastra 2014;Mehdipour et al 2017;Turner et al 2018), ultrafast outflows (e.g., Kraemer et al 2018;Reeves et al 2018), and quasar broad absorption lines (e.g., Krongold et al 2017;Hamann et al 2019;Leighly et al 2019).…”

Section: Introductionmentioning

confidence: 99%

The AGN broad line region as a clumpy turbulent outflow: a physical basis for LOC modeling

Waters,

2019

Preprint

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Many studies have considered the roles of clouds, outflows, and turbulence in producing the broad emission and absorption lines in the spectra of active galactic nuclei (AGNs). However, these are often treated as separate or even competing models. Here, we consider the possibility that AGN clouds are condensations formed within the thermally unstable zones of outflows and then compare the typical sizes of such condensations with the injection scale k −1 0 ∼ L 0 of turbulence, where L 0 is assumed to be the scale height of a representative global outflow model. We find that for broad line region (BLR) parameters, clouds are many orders of magnitude smaller than L 0 and this has the following implication: BLR cloud dynamics can be modeled using a local approximation through the use of multiphase turbulence simulations of X-ray irradiated plasmas. We present the first such 3D local clumpy turbulent outflow simulations. We show that the condensations share the same type of selection effects characterizing the locally optimally emitting cloud (LOC) scenario, thereby offering a physical interpretation for the LOC model and accounting for its almost uncanny successes. The ubiquitous presence of emission line regions in AGNs can be simply explained as the natural outcome of there being a multiphase interval of k-space within the inertial range of a turbulent cascade.

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Spectroscopic Observations of the Outflowing Wind in the Lensed Quasar SDSS J1001+5027^∗

Misawa

Inada²,

Oguri

et al. 2018

ApJ

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We performed spectroscopic observations of the small-separation lensed quasar SDSS J1001+5027, whose images have an angular separation θ = 2. ′′ 86, and placed constraints on the physical properties of gas clouds in the vicinity of the quasar (i.e., in the outflowing wind launched from the accretion disk). The two cylinders of sight to the two lensed images go through the same region of the outflowing wind and they become fully separated with no overlap at a very large distance from the source (∼330 pc). We discovered a clear difference in the profile of the C IV broad absorption line (BAL) detected in the two lensed images in two observing epochs. Because the kinematic components in the BAL profile do not vary in concert, the observed variations cannot be reproduced by a simple change of ionization state. If the variability is due to gas motion around the background source (i.e., the continuum source), the corresponding rotational velocity is v rot ≥ 18, 000 km s −1 , and their distance from the source is r ≤ 0.06 pc assuming Keplerian motion. Among three Mg II and three C IV NAL systems that we detected in the spectra, only the Mg II system at z abs = 0.8716 shows a hint of variability in its Mg I profile on a rest-frame time scale of ∆t rest ≤ 191 days and an obvious velocity shear between the sightlines whose physical separation is ∼ 7 kpc. We interpret this as the result of motion of a cosmologically intervening absorber, perhaps located in a foreground galaxy.

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Hubble Space Telescope observations of BALQSO Ton 34 reveal a connection between the broad-line region and the BAL outflow

Cited by 4 publications

References 86 publications

MCMC-based Voigt Profile fitting to a Mini-BAL System in the Quasar UM675

MCMC-based Voigt Profile fitting to a Mini-BAL System in the Quasar UM675

The AGN broad line region as a clumpy turbulent outflow: a physical basis for LOC modeling

Spectroscopic Observations of the Outflowing Wind in the Lensed Quasar SDSS J1001+5027^∗

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Hubble Space Telescope observations of BALQSO Ton 34 reveal a connection between the broad-line region and the BAL outflow

Cited by 4 publications

References 86 publications

MCMC-based Voigt Profile fitting to a Mini-BAL System in the Quasar UM675

MCMC-based Voigt Profile fitting to a Mini-BAL System in the Quasar UM675

The AGN broad line region as a clumpy turbulent outflow: a physical basis for LOC modeling

Spectroscopic Observations of the Outflowing Wind in the Lensed Quasar SDSS J1001+5027∗

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Product

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Spectroscopic Observations of the Outflowing Wind in the Lensed Quasar SDSS J1001+5027^∗