The time-dependent chemistry of cometary debris in the solar corona

Pesnell, W. D.; Bryans, P.

doi:10.1088/0004-637X/785/1/50

Title: The time-dependent chemistry of cometary debris in the solar corona

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Abstract

Recent improvements in solar observations have greatly progressed the study of sungrazing comets. They can now be imaged along the entirety of their perihelion passage through the solar atmosphere, revealing details of their composition and structure not measurable through previous observations in the less volatile region of the orbit further from the solar surface. Such comets are also unique probes of the solar atmosphere. The debris deposited by sungrazers is rapidly ionized and subsequently influenced by the ambient magnetic field. Measuring the spectral signature of the deposited material highlights the topology of the magnetic field and can reveal plasma parameters such as the electron temperature and density. Recovering these variables from the observable data requires a model of the interaction of the cometary species with the atmosphere through which they pass. The present paper offers such a model by considering the time-dependent chemistry of sublimated cometary species as they interact with the solar radiation field and coronal plasma. We expand on a previous simplified model by considering the fully time-dependent solutions of the emitting species' densities. To compare with observations, we consider a spherically symmetric expansion of the sublimated material into the corona and convert the time-dependent ion densities tomore »« less

Authors:

Pesnell, W. D. ^[1]; Bryans, P. ^[2]

NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States)
ADNET Systems Inc., NASA Goddard Space Flight Center, Code 671, Greenbelt, MD 20771 (United States)

Publication Date:: Thu Apr 10 00:00:00 EDT 2014

OSTI Identifier:: 22357162

Resource Type:: Journal Article

Journal Name:: Astrophysical Journal

Additional Journal Information:: Journal Volume: 785; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X

Country of Publication:: United States

Language:: English

Subject:: 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COMETS; COMPARATIVE EVALUATIONS; DENSITY; ELECTRON TEMPERATURE; EMISSION SPECTRA; EXPANSION; INTERACTIONS; ION DENSITY; MAGNETIC FIELDS; ORBITS; PLASMA; SIMULATION; SOLAR CORONA; SOLAR RADIATION; SPHERICAL CONFIGURATION; SUN; SYMMETRY; TIME DEPENDENCE; TOPOLOGY

Citation Formats


                    Pesnell, W. D., and Bryans, P. The time-dependent chemistry of cometary debris in the solar corona.  United States: N. p., 2014. 
        Web.  doi:10.1088/0004-637X/785/1/50.

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                    Pesnell, W. D., & Bryans, P. The time-dependent chemistry of cometary debris in the solar corona.  United States.  https://doi.org/10.1088/0004-637X/785/1/50

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                    Pesnell, W. D., and Bryans, P. 2014.  
        "The time-dependent chemistry of cometary debris in the solar corona".  United States.  https://doi.org/10.1088/0004-637X/785/1/50.

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@article{osti_22357162,

  title        = {The time-dependent chemistry of cometary debris in the solar corona},

  author       = {Pesnell, W. D. and Bryans, P.},

  abstractNote = {Recent improvements in solar observations have greatly progressed the study of sungrazing comets. They can now be imaged along the entirety of their perihelion passage through the solar atmosphere, revealing details of their composition and structure not measurable through previous observations in the less volatile region of the orbit further from the solar surface. Such comets are also unique probes of the solar atmosphere. The debris deposited by sungrazers is rapidly ionized and subsequently influenced by the ambient magnetic field. Measuring the spectral signature of the deposited material highlights the topology of the magnetic field and can reveal plasma parameters such as the electron temperature and density. Recovering these variables from the observable data requires a model of the interaction of the cometary species with the atmosphere through which they pass. The present paper offers such a model by considering the time-dependent chemistry of sublimated cometary species as they interact with the solar radiation field and coronal plasma. We expand on a previous simplified model by considering the fully time-dependent solutions of the emitting species' densities. To compare with observations, we consider a spherically symmetric expansion of the sublimated material into the corona and convert the time-dependent ion densities to radial profiles. Using emissivities from the CHIANTI database and plasma parameters derived from a magnetohydrodynamic simulation leads to a spatially dependent emission spectrum that can be directly compared with observations. We find our simulated spectra to be consistent with observation.},

  doi          = {10.1088/0004-637X/785/1/50},

  url          = {https://www.osti.gov/biblio/22357162},
  journal      = {Astrophysical Journal},

  issn         = {0004-637X},

  number       = 1,

  volume       = 785,

  place        = {United States},

  year         = {Thu Apr 10 00:00:00 EDT 2014},

  month        = {Thu Apr 10 00:00:00 EDT 2014}

}

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