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We present the modeling of partial frequency redistribution (PRD) effects for the fluorescent emission lines of molecular hydrogen, the general computational approximations, and the applications to planetary atmospheres, as well as…

Astrophysics · Physics 2015-05-13 R. E. Lupu , P. D. Feldman , S. R. McCandliss , K. France

Partial frequency redistribution (PRD), describing the formation of the line profile, has negligible observational effects for optical depths smaller than ~10^3, at the resolving power of most current instruments. However, when the spectral…

Earth and Planetary Astrophysics · Physics 2015-05-27 Roxana E. Lupu , Paul D. Feldman , Stephan R. McCandliss , Darrell F. Strobel

Aims: The polarization of the Ca II resonant doublet (H and K lines) and the subordinate infrared triplet lines are key observables for diagnosing solar chromospheric magnetism. It is thus necessary to understand the physical mechanisms…

Solar and Stellar Astrophysics · Physics 2026-01-14 I. Juanikorena Berasategi , E. Alsina Ballester , T. del Pino Alemán , J. Trujillo Bueno

We demonstrate that the atomic alignment of the hyperfine-structure components of the ground level S$_{1/2}$ of Na {\sc i} and of the upper level P$_{1/2}$ of the D$_1$ line are practically negligible for magnetic strengths $B>10 \rm G$,…

The linear polarization signals produced by scattering processes in strong resonance lines are rich in information on the magnetic and thermal structure of the chromosphere and transition region of the Sun and of other stars. A correct…

Solar and Stellar Astrophysics · Physics 2015-06-19 Luca Belluzzi , Javier Trujillo Bueno

We investigate the main physical mechanisms that shape the intensity and polarization of the Ba II D1 line at 4934 angstroms via radiative transfer numerical experiments. We focus especially on the scattering linear polarization arising…

Solar and Stellar Astrophysics · Physics 2024-01-24 E. Alsina Ballester , T. del Pino Alemán , J. Trujillo Bueno

The Sc II 4247 A line formed in the chromosphere is one of the lines well known, like the Na I D_2 and Ba II D_2, for its prominent triple peak structure in Q/I and the underlying quantum interference effects governing it. In this paper, we…

Solar and Stellar Astrophysics · Physics 2015-06-22 H. N. Smitha , K. N. Nagendra , J. O. Stenflo , M. Bianda , R. Ramelli

Several strong solar resonance lines show observable linear scattering polarization signals, holding a great potential for investigating the magnetism of the outer solar atmosphere. Accurately modeling these signals requires solving the…

The scattering polarization in the solar spectrum is traditionally modeled with each spectral line treated separately, but this is generally inadequate for multiplets where J-state interference plays a significant role. Through simultaneous…

Solar and Stellar Astrophysics · Physics 2015-06-04 H. N. Smitha , K. N. Nagendra , J. O. Stenflo , M. Bianda , M. Sampoorna , R. Ramelli , L. S. Anusha

The polarization of radiation by scattering on an atom embedded in combined external quadrupole electric and uniform magnetic fields is studied theoretically. Limiting cases of scattering under Zeeman effect and Hanle effect in weak…

Astrophysics · Physics 2015-06-24 Yee Yee Oo , M. Sampoorna , K. N. Nagendra , Sharath Ananthamurthy , G. Ramachandran

Using a quantum electrodynamical approach, we derive the scattering phase matrices for polarized radiation involving forbidden line transitions and in the presence of an external magnetic field. The case of (J=0->2->0) scattering is…

Astrophysics · Physics 2008-05-27 Yee Yee Oo , Phyu Phyu San , M. Sampoorna , K. N. Nagendra , G. Ramachandran

The spectral line polarization produced by optically pumped atoms contains a wealth of information on the thermal and magnetic structure of a variety of astrophysical plasmas, including that of the solar atmosphere. A correct decoding of…

Solar and Stellar Astrophysics · Physics 2015-05-30 Luca Belluzzi , Javier Trujillo Bueno

The modeling of the peculiar scattering polarization signals observed in some diagnostically important solar resonance lines requires the consideration of the detailed spectral structure of the incident radiation field as well as the…

Solar and Stellar Astrophysics · Physics 2015-12-02 Luca Belluzzi , Javier Trujillo Bueno , Egidio Landi Degl'Innocenti

Aims. The main goal of this paper is to present an accurate and efficient numerical strategy for solving the radiative transfer problem for polarised radiation in strong resonance lines forming out of local thermodynamic equilibrium, taking…

The polarization of radiation by scattering on an atom embedded in combined external quadrupole electric and uniform magnetic fields is studied theoretically. Analytic formulae are derived for the scattering phase matrix. Limiting cases of…

Astrophysics · Physics 2007-05-23 Yee Yee Oo , K. N. Nagendra , Sharath Ananthamurthy , G. Ramachandran

We have investigated the impact of circumplanetary rings consisting of spherical micrometer-sized particles on the net scattered light polarization of extrasolar gas giants. Using the three-dimensional Monte Carlo radiative transfer code…

Earth and Planetary Astrophysics · Physics 2023-03-15 M. Lietzow , S. Wolf

We briefly discuss the status of double parton scattering (DPS) on both theoretical and experimental sides and summarize the state of the naive DPS model, where the scatterers are taken completely independent. We then elaborate on some of…

High Energy Physics - Phenomenology · Physics 2015-08-12 Tomas Kasemets

This paper presents a numerical application of a self-consistent theory of partial redistribution in non-LTE conditions, developed in previous papers of the series. The code was described in a previous paper of this series. However, in that…

Solar and Stellar Astrophysics · Physics 2021-01-04 V. Bommier

Measurable linear scattering polarization signals have been predicted and detected at the solar disk center in the core of chromospheric lines. These forward-scattering polarization signals, which are of high interest for magnetic field…

Theoretical modeling of surface emission from magnetized neutron stars (NSs) requires proper treatment of QED effects, in particular the effect of photon mode conversion due to the ``vacuum resonance'' between plasma and vacuum…

Astrophysics · Physics 2009-11-11 Matthew van Adelsberg , Dong Lai