Plasma properties and stokes profiles during the lifetime of a photospheric magnetic bright point

R. L. Hewitt; S. Shelyag; M. Mathioudakis; F. P. Keenan

doi:10.1051/0004-6361/201322882

Plasma properties and stokes profiles during the lifetime of a photospheric magnetic bright point

R. L. Hewitt
, S. Shelyag
, M. Mathioudakis
, F. P. Keenan

Research output: Contribution to journal › Article › peer-review

14 Citations (Scopus)

Abstract

Aims. In this paper we aim to investigate the evolution of plasma properties and Stokes parameters in photospheric magnetic bright points using 3D magneto-hydrodynamical simulations and radiative diagnostics of solar granulation. Methods. Simulated time-dependent radiation parameters and plasma properties were investigated throughout the evolution of a bright point. Synthetic Stokes profiles for the FeI 630.25 nm line were calculated, which also allowed the evolution of the Stokes-I line strength and Stokes-V area and amplitude asymmetries to be investigated. Results. Our results are consistent with theoretical predictions and published observations describing convective collapse, and confirm this as the bright point formation process. Through degradation of the simulated data to match the spatial resolution of SOT, we show that high spatial resolution is crucial for the detection of changing spectro-polarimetric signatures throughout a magnetic bright point's lifetime. We also show that the signature downflow associated with the convective collapse process tends towards zero as the radiation intensity in the bright point peaks, because of the magnetic forces present restricting the flow of material in the flux tube.

Original language	English
Article number	A84
Journal	Astronomy and Astrophysics
Volume	565
DOIs	https://doi.org/10.1051/0004-6361/201322882
Publication status	Published - May 2014
Externally published	Yes

Bibliographical note

Funding Information:
This work is supported by the UK Science and Technology Facilities Council. R.L.H. would like to thank the Department of Education and Learning of Northern Ireland for the award of a Ph.D. studentship. This research was undertaken with the assistance of resources provided at the NCI National Facility systems at the Australian National University, supported by Astronomy Australia Limited, and at the Multi-modal Australian ScienceS Imaging and Visualisation Environment (MASSIVE; www.massive.org.au ). The authors also thank the Centre for Astrophysics & Supercomputing of Swinburne University of Technology (Australia) for the computational resources provided. Dr Shelyag is the recipient of Australian Research Council’s Future Fellowship (project number FT120100057).

Keywords

Sun:magnetic fields
Sun:photosphere

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Cite this

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title = "Plasma properties and stokes profiles during the lifetime of a photospheric magnetic bright point",

abstract = "Aims. In this paper we aim to investigate the evolution of plasma properties and Stokes parameters in photospheric magnetic bright points using 3D magneto-hydrodynamical simulations and radiative diagnostics of solar granulation. Methods. Simulated time-dependent radiation parameters and plasma properties were investigated throughout the evolution of a bright point. Synthetic Stokes profiles for the FeI 630.25 nm line were calculated, which also allowed the evolution of the Stokes-I line strength and Stokes-V area and amplitude asymmetries to be investigated. Results. Our results are consistent with theoretical predictions and published observations describing convective collapse, and confirm this as the bright point formation process. Through degradation of the simulated data to match the spatial resolution of SOT, we show that high spatial resolution is crucial for the detection of changing spectro-polarimetric signatures throughout a magnetic bright point's lifetime. We also show that the signature downflow associated with the convective collapse process tends towards zero as the radiation intensity in the bright point peaks, because of the magnetic forces present restricting the flow of material in the flux tube.",

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author = "Hewitt, \{R. L.\} and S. Shelyag and M. Mathioudakis and Keenan, \{F. P.\}",

note = "Funding Information: This work is supported by the UK Science and Technology Facilities Council. R.L.H. would like to thank the Department of Education and Learning of Northern Ireland for the award of a Ph.D. studentship. This research was undertaken with the assistance of resources provided at the NCI National Facility systems at the Australian National University, supported by Astronomy Australia Limited, and at the Multi-modal Australian ScienceS Imaging and Visualisation Environment (MASSIVE; www.massive.org.au ). The authors also thank the Centre for Astrophysics \& Supercomputing of Swinburne University of Technology (Australia) for the computational resources provided. Dr Shelyag is the recipient of Australian Research Council{\textquoteright}s Future Fellowship (project number FT120100057).",

year = "2014",

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doi = "10.1051/0004-6361/201322882",

language = "English",

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AU - Hewitt, R. L.

AU - Shelyag, S.

AU - Mathioudakis, M.

AU - Keenan, F. P.

N1 - Funding Information: This work is supported by the UK Science and Technology Facilities Council. R.L.H. would like to thank the Department of Education and Learning of Northern Ireland for the award of a Ph.D. studentship. This research was undertaken with the assistance of resources provided at the NCI National Facility systems at the Australian National University, supported by Astronomy Australia Limited, and at the Multi-modal Australian ScienceS Imaging and Visualisation Environment (MASSIVE; www.massive.org.au ). The authors also thank the Centre for Astrophysics & Supercomputing of Swinburne University of Technology (Australia) for the computational resources provided. Dr Shelyag is the recipient of Australian Research Council’s Future Fellowship (project number FT120100057).

PY - 2014/5

Y1 - 2014/5

N2 - Aims. In this paper we aim to investigate the evolution of plasma properties and Stokes parameters in photospheric magnetic bright points using 3D magneto-hydrodynamical simulations and radiative diagnostics of solar granulation. Methods. Simulated time-dependent radiation parameters and plasma properties were investigated throughout the evolution of a bright point. Synthetic Stokes profiles for the FeI 630.25 nm line were calculated, which also allowed the evolution of the Stokes-I line strength and Stokes-V area and amplitude asymmetries to be investigated. Results. Our results are consistent with theoretical predictions and published observations describing convective collapse, and confirm this as the bright point formation process. Through degradation of the simulated data to match the spatial resolution of SOT, we show that high spatial resolution is crucial for the detection of changing spectro-polarimetric signatures throughout a magnetic bright point's lifetime. We also show that the signature downflow associated with the convective collapse process tends towards zero as the radiation intensity in the bright point peaks, because of the magnetic forces present restricting the flow of material in the flux tube.

AB - Aims. In this paper we aim to investigate the evolution of plasma properties and Stokes parameters in photospheric magnetic bright points using 3D magneto-hydrodynamical simulations and radiative diagnostics of solar granulation. Methods. Simulated time-dependent radiation parameters and plasma properties were investigated throughout the evolution of a bright point. Synthetic Stokes profiles for the FeI 630.25 nm line were calculated, which also allowed the evolution of the Stokes-I line strength and Stokes-V area and amplitude asymmetries to be investigated. Results. Our results are consistent with theoretical predictions and published observations describing convective collapse, and confirm this as the bright point formation process. Through degradation of the simulated data to match the spatial resolution of SOT, we show that high spatial resolution is crucial for the detection of changing spectro-polarimetric signatures throughout a magnetic bright point's lifetime. We also show that the signature downflow associated with the convective collapse process tends towards zero as the radiation intensity in the bright point peaks, because of the magnetic forces present restricting the flow of material in the flux tube.

KW - Sun:magnetic fields

KW - Sun:photosphere

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DO - 10.1051/0004-6361/201322882

M3 - Article

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SN - 0004-6361

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JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

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ER -

Plasma properties and stokes profiles during the lifetime of a photospheric magnetic bright point

Abstract

Bibliographical note

Keywords

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