author={T.J.Turner and L.Miller and J.N.Reeves and Andrew Lobban and Valentina Braito and S. B. Kraemer and D. Michael Crenshaw},
  journal={The Astrophysical Journal},
A Suzaku X-ray observation of NGC 4051 taken during 2005 November reveals line emission at 5.44 keV in the rest frame of the galaxy which does not have an obvious origin in known rest-frame atomic transitions. The improvement to the fit statistic when this line is accounted for establishes its reality at >99.9% confidence: we have also verified that the line is detected in the three X-ray Imaging Spectrometer units independently. Comparison between the data and Monte Carlo simulations shows… Expand

Figures and Tables from this paper

Evidence for a circumnuclear and ionized absorber in the X-ray obscured broad-line radio galaxy 3C 445
Here we present the results of a Suzaku observation of the Broad Line Radio Galaxy 3C 445. We confirm the results obtained with the previous X-ray observations which unveiled the presence of severalExpand
Variability of the High-velocity Outflow in the Quasar PDS 456
We present a comparison of two Suzaku X-ray observations of the nearby (z = 0.184), luminous (L bol ~ 1047 erg s–1) type I quasar, PDS 456. A new 125 ks Suzaku observation in 2011 caught the quasarExpand
Contemporaneous Chandra HETG and Suzaku X-ray Observations of NGC 4051
We present the results of a deep 300 ks Chandra HETG observation of the highly variable narrow-line Seyfert Type 1 galaxy NGC 4051. The HETG spectrum reveals 28 significant soft X-ray ionised linesExpand
An extreme gravitationally redshifted iron line at 4.8 keV in Mrk 876
X-ray spectral lines at unforeseen energies are important because they can shed light on the extreme physical conditions of the environment around the supermassive black holes of active galacticExpand
Observations of Outflowing Ultraviolet Absorbers in NGC 4051 with the Cosmic Origins Spectrograph
We present new Hubble Space Telescope (HST)/Cosmic Origins Spectrograph (COS) observations of the narrow-line Seyfert 1 galaxy NGC 4051. These data were obtained as part of a coordinated observingExpand
Modeling the Fe K Line Profiles in Type I Active Galactic Nuclei with a Compton-thick Disk Wind
We have modeled a small sample of Seyfert galaxies that were previously identified as having simple X-ray spectra with little intrinsic absorption. The sources in this sample all contain moderatelyExpand
Multiphase, non-spherical gas accretion on to a black hole
We investigate non-spherical behaviour of gas accreting on to a central supermassive black hole. Assuming optically thin conditions, we include radiative cooling and radiative heating by the centralExpand
Extremal energy shifts of radiation from a ring near a rotating black hole
Radiation from a narrow circular ring shows a characteristic double-horn profile dominated by photons having energy around the maximum or minimum of the allowed range, i.e. near the extremal valuesExpand


X-Ray Spectral Variability of the Seyfert Galaxy NGC 4051 Observed with Suzaku
We report results from a Suzaku observation of the narrow-line Seyfert 1 NGC 4051. During our observation, large amplitude rapid variability is seen and the averaged 2--10 keV flux is 8.1x10^-12 ergExpand
Occultation Measurement of the Size of the X-Ray-emitting Region in the Active Galactic Nucleus of NGC 1365
We present an occultation of the central X-ray-emitting region in the Seyfert galaxy NGC 1365. This extreme spectral variation (from Compton-thin to reflection-dominated and back to Compton-thin in 4Expand
XMM-Newton observation of the Seyfert 1.8 ESO 113-G010: discovery of a highly redshifted iron line at 5.4 keV.
We present a spectral analysis of the Seyfert 1.8 ESO 113-G010 observed with XMM-Newton for 4 ks. The spectrum shows a soft excess below 0.7 keV and more interestingly a narrow emission Gaussian lineExpand
Tracing a Disk Wind in NGC 3516
Context. X-ray spectra of AGN often contain signatures indicative of absorption in multiple layers of gas whose ionization-state and covering fraction may vary with time. It has been unclear to dateExpand
Cosmic-ray Spallation in Radio-quiet Active Galactic Nuclei: A Case Study of NGC 4051
We investigate conditions for and consequences of spallation in radio-quiet Seyfert galaxies. The work is motivated by the recent discovery of significant line emission at 5.44 keV in Suzaku dataExpand
Exploring the complex X-ray spectrum of NGC 4051
Archival XMM‐Newton data on the nearby Seyfert galaxy NGC 4051, taken in relatively highand low-flux states, offer a unique opportunity to explore the complexity of its X-ray spectrum. We find theExpand
On the evidence for narrow, relativistically shifted X-ray lines
In recent years, there have been many reported detections of highly redshifted or blueshifted narrow spectral lines (both emission or absorption) in the X-ray spectra of active galaxies, but theseExpand
An absorption origin for the X-ray spectral variability of MCG-6-30-15
Context. The Seyfert I galaxy MCG–6-30-15 shows one of the best examples of a broad “red wing” of emission in its X-ray spectrum at energies 2 20 keV. Methods. We compiled all the availableExpand
XMM–Newton study of the complex and variable spectrum of NGC 4051
We study the X-ray spectral variability of the narrow line Seyfert 1 galaxy NGC 4051 as observed during two XMM-Newton observations. To gain insight on the general behaviour, we first applyExpand
Fe K Emission and Absorption in the XMM-EPIC Spectrum of the Seyfert Galaxy IC 4329a
We present a detailed analysis of the XMM-Newton long-look of the Seyfert galaxy IC 4329a. The Fe K bandpass is dominated by two resolved peaks at 6.4 and 7.0 keV, consistent with neutral orExpand