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Creators/Authors contains: "Eracleous, M"

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  1. Context.Accretion disk winds launched close to supermassive black holes (SMBHs) are a viable mechanism providing feedback between the SMBH and the host galaxy. Aims.We aim to characterize the X-ray properties of the inner accretion disk wind of the nearby active galactic nucleus PG 1126-041 and to study its connection with the UV-absorbing wind. Methods.We performed a spectroscopic analysis of eightXMM-Newtonobservations of PG 1126-041 taken between 2004 and 2015, using both phenomenological models and the most advanced accretion disk wind models available. For half of the data set, we were able to compare the X-ray analysis results with the results of quasi-simultaneous, high-resolution, spectroscopic UV observations taken with the Cosmic Origins Spectrograph on board theHubbleSpace Telescope. Results.The X-ray spectra of PG 1126-041 are complex and absorbed by ionized material, which is highly variable on multiple timescales, sometimes as short as 11 days. Accretion disk wind models can account for most of the X-ray spectral complexity of PG 1126-041, with the addition of massive clumps, represented by a partially covering absorber. Variations in column density (NH ∼ 5 − 20 × 1022cm−2) of the partially covering absorber drive the observed X-ray spectral variability of PG 1126-041. The absorption from the X-ray partially covering gas and from the blueshifted C IVtroughs appear to vary in a coordinated way. Conclusions.The line of sight toward PG 1126-041 offers a privileged view through a highly dynamic nuclear wind originating on inner accretion disk scales, making the source a very promising candidate for future detailed studies of the physics of accretion disk winds around SMBHs. 
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  2. ABSTRACT We present Multi-Unit Spectroscopic Explorer (MUSE) integral-field spectroscopy of ESO 253−G003, which hosts a known active galactic nucleus (AGN) and the periodic nuclear transient ASASSN-14ko, observed as part of the All-weather MUse Supernova Integral-field of Nearby Galaxies survey. The MUSE observations reveal that the inner region hosts two AGN separated by $$1.4\pm 0.1~\rm {kpc}$$ (≈1$${_{.}^{\prime\prime}}$$7). The brighter nucleus has asymmetric broad permitted emission-line profiles and is associated with the archival AGN designation. The fainter nucleus does not have a broad emission-line component but exhibits other AGN characteristics, including $$\hbox{$$v_{\rm {FWHM}}$$} \approx 700~\hbox{km~s$$^{-1}$$}$$ forbidden line emission, $$\rm{\log _{10}(\rm{[O\,\small {III}]}/\rm{H\beta})} \approx 1.1$$, and high-excitation potential emission lines, such as [Fe vii] λ6086 and He ii λ4686. The host galaxy exhibits a disturbed morphology with large kpc-scale tidal features, potential outflows from both nuclei, and a likely superbubble. A circular relativistic disc model cannot reproduce the asymmetric broad emission-line profiles in the brighter nucleus, but two non-axisymmetric disc models provide good fits to the broad emission-line profiles: an elliptical disc model and a circular disc + spiral arm model. Implications for the periodic nuclear transient ASASSN-14ko are discussed. 
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  3. null (Ed.)