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A sublimation process governs the innermost region of the dusty torus of active galactic nuclei. However, the observed inner radius of the torus is systematically smaller than the expected radius by a factor of ~ 1/3. We show that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Toshihiro Kawaguchi , Masao Mori

Spectropolarimetry from the near IR to the far UV of light scattered by dust provides a valuable diagnostic of the dust composition, grain size distribution and spatial distribution. To facilitate the use of this diagnostic, we present…

Astrophysics · Physics 2009-10-31 Victor G. Zubko , Ari Laor

We present Monte Carlo simulations of dusty spiral galaxies, modelled as bulge + disk systems, aimed to study their extinction and polarization properties. The extinction parameters (absorption and scattering) of dust grains are calculated…

Astrophysics · Physics 2009-10-28 Simone Bianchi , Andrea Ferrara , Carlo Giovanardi

Interference terms between monopole and quadrupole Coulomb form factors that contribute to the cross-section of electron scattering from polarized nuclei are studied within the plane wave Born approximation. By experimentally exploring the…

Nuclear Theory · Physics 2024-02-14 Pedro Sarriguren

The intense magnetic fields of neutron stars naturally lead to strong anisotropy and polarization of radiation emanating from their surfaces, both being sensitive to the hot spot position on the surface. Accordingly, pulse phase-resolved…

High Energy Astrophysical Phenomena · Physics 2025-02-21 Matthew G. Baring , Hoa Dinh Thi , George A. Younes , Kun Hu

Optical polarization signal coming from the innermost part of active galactic nuclei (AGNs) is highly sensitive on the geometry and kinematics of the central engine. Due to the compact size of the AGN central region, which is spatially…

Astrophysics of Galaxies · Physics 2019-04-01 Đorđe Savić

In this second research note of a series of two, we aim to map the polarized flux emerging from a disk-born, dusty outflow as it was prescribed by Elvis (2000). His structure for quasars was achieved to unify the emission and absorption…

High Energy Astrophysical Phenomena · Physics 2019-08-19 F. Marin , R. W. Goosmann

We report results from HST/NICMOS 2 micron imaging polarimetry of the central region of Centaurus A. In the vicinity of the nucleus we observe a complex polarization structure which we explain by a combination of scattering of nuclear light…

We study 12 Seyfert 1 galaxies with a high level of optical polarization. Optical light emerging from the innermost regions is predominantly scattered in a polar region above the central engine directly in our line of sight. These sources…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-27 Tobias Beuchert , Jörn Wilms , Matthias Kadler , Anna Lia Longinotti , Matteo Guainazzi , Giovanni Miniutti , Ignacio de la Calle

The circular polarization of light scattered by biological tissues provides valuable information and has been considered as a powerful tool for the diagnosis of tumor tissue. We propose a non-staining, non-invasive and in-vivo cancer…

Optical observations cannot resolve the structure of active galactic nuclei (AGN), and a unified model for AGN was inferred mostly from indirect methods. Optical reverberation mapping allowed us to constrain the spatial dimension of the…

High Energy Astrophysical Phenomena · Physics 2017-12-05 P. A. Rojas Lobos , R. W. Goosmann , F. Marin , D. Savić

We present detailed scattering models confirming that distinctive variations in polarization across the broad Halpha line, which are observed in a significant fraction of Seyfert 1 galaxies, can be understood in terms of a rotating…

Astrophysics · Physics 2014-10-13 J. E. Smith , A. Robinson , S. Young , D. J. Axon , Elizabeth A. Corbett

We have analyzed the deep Chandra observation (~155 ks) of the Compton Thick Active Galactic Nucleus (CT AGN) ESO 428-G014, to study in detail the morphology of the diffuse X-ray emission in the inner ~500 pc radius region. Comparing…

High Energy Astrophysical Phenomena · Physics 2018-10-10 G. Fabbiano , A. Paggi , M. Karovska , M. Elvis , W. P. Maksym , Junfeng Wang

We present Monte Carlo simulations of the Diffuse H$\alpha$ Galactic Background. Our models comprise direct and multiply scattered H$\alpha$ radiation from the kpc scaleheight Warm Ionized Medium and midplane H II regions. The scattering is…

Astrophysics · Physics 2008-11-26 Kenneth Wood , Ron Reynolds

Polarisation is a decisive method to study the inner region of active galactic nuclei (AGNs) since it is not affected by contrast issues similarly to how classical imaging is. When coupled to high angular resolution (HAR), polarisation can…

Astrophysics of Galaxies · Physics 2021-04-14 L. Grosset , D. Rouan , F. Marin , D. Gratadour , E. Lagadec , S. Hunziker , M. Montargès , Y. Magnard , M. Carle , J. Pragt , C. Petit

We present new calculations of X-ray polarization from accreting black holes (BHs), using a Monte-Carlo ray-tracing code in full general relativity. In our model, an optically thick disk in the BH equatorial plane produces thermal seed…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Jeremy D. Schnittman , Julian H. Krolik

We describe the incorporation of polarized radiative transfer into the atmospheric radiative transfer modelling code VSTAR (Versatile Software for Transfer of Atmospheric Radiation). Using a vector discrete-ordinate radiative transfer code…

Earth and Planetary Astrophysics · Physics 2018-08-01 Jeremy Bailey , Lucyna Kedziora-Chudczer , Kimberly Bott

We consider the polarization arising from scattering in an envelope illuminated by a central anisotropic source. Spherical harmonics are used to describe both the light source anisotropy and the envelope density distribution functions of…

Astrophysics · Physics 2008-12-16 R Ignace , M Al-Malki , J Simmons , J C Brown , D Clarke , J Carson

Virtual Compton scattering in the $\Delta$-resonance region is considered in the case of a target nucleus. The discussion involves generalized polarizabilities and is developed for zero-spin nuclei, focusing on the new information coming…

Nuclear Theory · Physics 2009-10-30 B. Pasquini , S. Boffi

We investigated the impact of selected cloud condensates in exoplanetary atmospheres on the polarization of scattered stellar radiation. We considered a selection of 25 cloud condensates that are expected to be present in extrasolar…

Earth and Planetary Astrophysics · Physics 2022-07-13 Moritz Lietzow , Sebastian Wolf