<i>NuSTAR</i>AND<i>XMM-NEWTON</i>OBSERVATIONS OF NGC 1365: EXTREME ABSORPTION VARIABILITY AND A CONSTANT INNER ACCRETION DISK

Walton, D. J.; Risaliti, G.; Harrison, Fiona A.; Fabian, A. C.; Miller, J. M.; Arévalo, P.; Ballantyne, D. R.; Boggs, Steven E.; Brenneman, Laura; Christensen, Finn Erland; Craig, William W.; Elvis, M.; Fuerst, F.; Gandhi, P.; Grefenstette, Brian W.; Hailey, Charles J.; Kara, Erin; Luo, Birong; Madsen, K. K.; Marinucci, Andrea; Matt, Giorgio; Parker, M. L.; Reynolds, C. S.; Rivers, Elizabeth; Ross, R. R.; Stern, Daniel; Zhang, W. W.

doi:10.1088/0004-637x/788/1/76

Cited by 103 publications

(119 citation statements)

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“…The results of the broadband analysis of the first observation (performed on 2012 July 25-27) and the determination of the possible spin parameters of the central black hole were recently published in Risaliti et al (2013) and Walton et al (2014). During this monitoring program NGC 1365 showed a new and even more dramatic spectral variability, which for the first time affected also the soft X-ray emission and which we consider in more detail here.…”

Section: Introductionmentioning

confidence: 93%

“…During this monitoring program NGC 1365 showed a new and even more dramatic spectral variability, which for the first time affected also the soft X-ray emission and which we consider in more detail here. While the first of these observations caught the source in its standard Compton-thin state (N H ∼ 3×10 23 cm −2 ), during the following observations (performed in 2012 December, 2013 January, and 2013 February) the primary power-law flux increased by a factor of three and more importantly during the third observation the N H dropped to ∼10 22 cm −2 (E. Rivers et al, in preparation;Walton et al 2014). The overall X-ray emission is now reminiscent of a weakly obscured AGN with the lowenergy photoelectric cut-off at about 1 keV.…”

Section: Introductionmentioning

confidence: 99%

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NGC 1365: A Low Column Density State Unveiling a Low Ionization Disk Wind

Braito

Reeves

Gofford

et al. 2014

ApJ

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We present the time-resolved spectral analysis of the XMM-Newton data of NGC 1365 collected during one XMMNewton observation, which caught this "changing-look" active galactic nucleus in a high flux state characterized also by a low column density (N H ∼ 10 22 cm −2 ) of the X-ray absorber. During this observation, the low-energy photoelectric cut-off is at about ∼1 keV and the primary continuum can be investigated with the XMM-Newton-RGS data, which show strong spectral variability that can be explained as a variable low N H that decreased from N H ∼ 10 23 cm −2 to 10 22 cm −2 in a 100 ks timescale. The spectral analysis of the last segment of the observation revealed the presence of several absorption features that can be associated with an ionized (log ξ ∼ 2 erg cm s −1 ) outflowing wind (v out ∼ 2000 km s −1 ). We detected for the first time a possible P-Cygni profile of the Mg xii Lyα line associated with this mildly ionized absorber indicative of a wide angle outflowing wind. We suggest that this wind is a low ionization zone of the highly ionized wind present in NGC 1365, which is responsible for the iron K absorption lines and is located within the variable X-ray absorber. At the end of the observation, we detected a strong absorption line at E ∼ 0.76 keV most likely associated with a lower ionization zone of the absorber (log ξ ∼ 0.2 erg cm s −1 , N H ∼ 10 22 cm −2 ), which suggests that the variable absorber in NGC 1365 could be a low ionization zone of the disk wind.

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Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

NGC 1365: A Low Column Density State Unveiling a Low Ionization Disk Wind

Braito

Reeves

Gofford

et al. 2014

ApJ

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“…Indeed, major changes in the X-ray column density have been observed in several nearby AGN, on time-scales of months to years (e.g. Puccetti et al 2007;Walton et al 2014).…”

Section: Variabilitymentioning

confidence: 99%

Reaching the peak of the quasar spectral energy distribution – I. Observations and models

Collinson

Ward

Done

et al. 2015

Monthly Notices of the Royal Astronomical Society

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We perform a spectral analysis of a sample of 11 medium redshift (1.5 z 2.2) quasars. Our sample all have optical spectra from the SDSS, infrared spectra from GNIRS and TSPEC, and X-ray spectra from XMM-Newton. We first analyse the Balmer broad emission line profiles which are shifted into the IR spectra to constrain black hole masses. Then we fit an energy-conserving, three component accretion model of the broadband spectral energy distribution (SED) to our multiwavelength data. Five out of the 11 quasars show evidence of an SED peak, allowing us to constrain their bolometric luminosity from these models and estimate their mass accretion rates. Based on our limited sample, we suggest that estimating bolometric luminosities from L 5100 Å and L 2−10 keV may be unreliable, as has been also noted for a low-redshift, X-ray selected AGN sample.

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“…Turner et al 1997Turner et al , 1998 but also type 1 and intermediate Seyferts (e.g., Malizia et al 1997;Pounds et al 2004;Miller et al 2007;Bianchi et al 2009;Turner et al 2009;Risaliti et al 2010;Lobban et al 2011;Marchese et al 2012;Longinotti et al 2009Longinotti et al , 2013Reeves et al 2013;Walton et al 2014;Miniutti et al 2014;Rivers et al 2015). In some cases, the columns are so large that astronomers have called these "changing look" sources (i.e.…”

Section: Introductionmentioning

confidence: 99%

Anatomy of the AGN in NGC 5548

Cappi

Marco

Ponti

et al. 2016

A&A

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In 2013, we conducted a large multi-wavelength campaign on the archetypical Seyfert 1 galaxy NGC 5548. Unexpectedly, this usually unobscured source appeared strongly absorbed in the soft X-rays during the entire campaign, and signatures of new and strong outflows were present in the almost simultaneous UV HST/COS data. Here we carry out a comprehensive spectral analysis of all available XMM-Newton observations of NGC 5548 (precisely 14 observations from our campaign plus three from the archive, for a total of ∼763 ks) in combination with three simultaneous NuSTAR observations. We obtain a best-fit underlying continuum model composed by i) a weakly varying flat (Γ ∼ 1.5-1.7) power-law component; ii) a constant, cold reflection (FeK + continuum) component; iii) a soft excess, possibly owing to thermal Comptonization; and iv) a constant, ionized scattered emission-line dominated component. Our main findings are that, during the 2013 campaign, the first three of these components appear to be partially covered by a heavy and variable obscurer that is located along the line of sight (LOS), which is consistent with a multilayer of cold and mildly ionized gas. We characterize in detail the short timescale (mostly ∼ks-to-days) spectral variability of this new obscurer, and find it is mostly due to a combination of column density and covering factor variations, on top of intrinsic power-law (flux and slope) variations. In addition, our best-fit spectrum is left with several (but marginal) absorption features at rest-frame energies ∼6.7−6.9 keV and ∼8 keV, as well as a weak broad emission line feature redwards of the 6.4 keV emission line. These could indicate a more complex underlying model, e.g. a P-Cygni-type emission profile if we allow for a large velocity and wide-angle outflow. These findings are consistent with a picture where the obscurer represents the manifestation along the LOS of a multilayer of gas, which is also in multiphase, and which is likely outflowing at high speed, and simultaneously producing heavy obscuration and scattering in the X-rays, as well as broad absorption features in the UV.

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NuSTARANDXMM-NEWTONOBSERVATIONS OF NGC 1365: EXTREME ABSORPTION VARIABILITY AND A CONSTANT INNER ACCRETION DISK

Cited by 103 publications

References 99 publications

NGC 1365: A Low Column Density State Unveiling a Low Ionization Disk Wind

NGC 1365: A Low Column Density State Unveiling a Low Ionization Disk Wind

Reaching the peak of the quasar spectral energy distribution – I. Observations and models

Anatomy of the AGN in NGC 5548

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