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| Paper: |
Polarized Line Formation in Spherically Symmetric Expanding Atmospheres |
| Volume: |
519, Radiative Signatures from the Cosmos |
| Page: |
27 |
| Authors: |
Megha, A.; Sampoorna, M.; Nagendra, K. N.; Anusha, L. S.; Sankarasubramanian, K. |
| Abstract: |
We consider the problem of polarized line formation
in the spherically symmetric expanding atmospheres. The
velocity fields in line forming regions produce Doppler shift,
aberration of photons and also gives rise to advection. These
in turn can modify the amplitudes and shapes of the emergent
Stokes profiles. However, here we consider only non-relativistic
regime, wherein mainly Doppler shift effects are significant. Thus only
Doppler shift terms are considered in the polarized transfer equation.
For the solution of the concerned
polarized transfer equation we use the comoving frame formulation, and apply
the Accelerated Lambda Iteration (ALI) method. We present the results by
considering the scattering on a two-level atom, including the effects of
partial frequency redistribution (PFR). The polarized line profiles are
shown for few velocity laws, representative of expanding spherical
atmospheres. It is shown that the degree of polarization in the lines
depends sensitively on the extendedness R of the spherical
atmosphere. We also present a comparison of polarized profiles
computed under complete frequency redistribution (CFR) and PFR in the
case of static as well as expanding atmospheres. |
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