The central engines of both type 1 and type 2 AGNs are thought to harbor a toroidal structure that absorbs and reprocesses high-energy photons from the central X-ray source. If the reprocessor is Compton-thick, the calculation of emission-line and continuum spectra that are suitable for direct fitting to X-ray data is challenging because the reprocessed emission depends on the spectral shape of the incident continuum, which may not be directly observable. We present new Monte-Carlo calculations of Green's functions for a toroidal reprocessor that provide significant improvements over currently available models. The Green's function approach enables the construction of X-ray spectral fitting models that allow arbitrary incident spectra as part of the fitting process. The calculations are fully relativistic and have been performed for column densities that cover the Compton-thin to Compton-thick regime, for incident photon energies up to 500 keV. The reprocessed continuum and fluorescent line emission due to Fe Ka, Fe Kb, and Ni Ka are treated self-consistently, eliminating the need for ad hoc modeling that is currently common practice. We find that the spectral shape of the Compton-thick reflection spectrum in both the soft and hard X-ray bands in our toroidal geometry is different compared to that obtained from disk models. A key result of our study is that a Compton-thick toroidal structure that subtends the same solid angle at the X-ray source as a disk can produce a reflection spectrum that is ~6 times weaker than that from a disk. This highlights the widespread and erroneous interpretation of the so-called "reflection-fraction" as a solid angle, obtained from fitting disk-reflection models to Compton-thick sources without regard for proper consideration of geometry. (Abridged)
A joint XMM-Newton and NuSTAR observation was conducted for the bright, local Seyfert 1.9 galaxy, NGC 1194. The hard spectral form of this AGN was modeled using the toroidal reprocessor MYTORUS. The decoupled model form provides a good description of the spectrum, with reflection arising from gas with a global average column density > 4 x 10^24 cm^-2 and transmission of the continuum through an order-of-magnitude lower column. In this model, the reflection strength is a factor ~3 higher than expected from a simple torus. Such a result may indicate that much of the intrinsic X-ray continuum is …
We present a new analysis of the Suzaku X-ray spectrum of the Compton-thin Seyfert 2 galaxy NGC 4388. The spectrum above $\sim$2 keV can be described by a remarkably simple and rather mundane model, consisting of a uniform, neutral spherical distribution of matter, with a radial column density of $2.58 \pm 0.02 \times 10^{23}$ cm$^{-2}$, and an Fe abundance of $1.102^{+0.024}_{-0.021}$ relative to solar. The model does not require any phenomenological adjustments to self-consistently account for the low-energy extinction, the Fe K$α$ and Fe K$β$ fluorescent emission lines, the Fe K edge, and t…
X-ray data for quasar 4C 74.26 have previously been modeled with a broad Fe K$α$ emission line and reflection continuum originating in the inner part of the accretion disk around the central supermassive black hole (SMBH), i.e. the strong gravity regime. We modeled broadband X-ray spectra from $Suzaku$ and $NuSTAR$ with MYTORUS, self-consistently accounting for Fe K$α$ line emission, as well as direct and reflected continuum emission, from finite column density matter. A narrow Fe K$α$ emission line originating in an X-ray reprocessor with solar Fe abundance far from the central SMBH is suffic…
A XRISM view of the iron line complex in NGC 1068: Rethinking the prototypical Compton-thick AGN
European Space Agency (ESA)(欧洲空间局);European Space Research and Technology Centre (ESTEC)(欧洲空间研究与技术中心);Sterrenkundig Observatorium, Universiteit Gent(根特大学天文台);INAF Osservatorio Astrofisico di Arcetri(意大利国家天体物理研究所阿切特里天文台);INAF Osservatorio Astronomico di Brera(意大利国家天体物理研究所布雷拉天文台);The Catholic University of America(美利坚天主教大学);Università di Trento(特伦托大学);INAF Osservatorio di Astrofisica e Scienza dello Spazio di Bologna (OAS)(意大利国家天体物理研究所博洛尼亚天体物理与空间科学观测站);Università degli Studi di Roma “Tor Vergata”(罗马第二大学);“Sapienza” Università di Roma(罗马第一大学);INAF Istituto di Astrofisica e Planetologia Spaziali(意大利国家天体物理研究所天体物理学与行星科学研究所)
We have carried out an extensive X-ray spectral study of the bare Seyfert-1 galaxy MCG--02--58--22 to ascertain the nature of the X-ray reprocessing media, using observations from Suzaku (2009) and simultaneous observations from XMM-Newton and NuSTAR (2016) . The most significant results of our investigation are: 1. The primary X-ray emission from the corona is constant in these observations, both in terms of the power law slope ($Γ=1.80$) and luminosity ($L_{2-10 \rm keV}= 2.55\times 10^{44} $ erg/s). 2. The soft excess flux decreased by a factor of two in 2016, the Compton hump weakened/vani…
Broad-band Spectral Modeling of Large-Scale X-ray Jets in High-Redshift Quasars: An MHD-Informed Approach
Astronomical Observatory of the Jagiellonian University(雅盖隆大学天文台);Jagiellonian University(雅盖隆大学);Naval Research Laboratory(海军研究实验室);INAF—Istituto di Radioastronomia(意大利国家天体物理研究所射电天文台);Center for Astrophysics, Harvard & Smithsonian(哈佛与史密森尼天体物理中心)