Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Temperature Diagnostic Properties of the MG I 457.1 NM Line   We analyze the important formation processes for the Mg I 457.1 nm line. This
line is an intercom- bination line and the source function is close to the
local thermodynamic equilibrium (LTE) value. The strong coupling to the local
temperature and the relatively high population of the lower level (the ground
state of Mg I) makes this line an ideal candidate for temperature diagnostics
in the lower chromosphere/temperature minimum region. Linking the temperature
probed to an absolute phys- ical height is non trivial because of Non-LTE
ionization. We analyze the Non-LTE effects and find that photo-ionization from
the lower energy levels together with cascading collisional recombination
dominate the ionization balance. Taking properly into account the
line-blanketing in the UV is essen- tial for obtaining the right
photoionization rates. The identification of the main Non-LTE effects in the
line allows us to construct a quintessential model atom, ideal for
computationally demanding tasks, e.g. full 3D and/or time-dependent radiative
transfer. Furthermore we analyze the diagnostic potential to temperature of
this line in solar-like atmospheres, by synthesizing the line from a series of
parametrized atmospheric models. These models have been constructed with fixed
effective temper- ature, but with a variable heat term in the energy equation
to obtain a chromospheric temperature rise at different heights. We conclude
that the line has a significant potential in the diagnostics of the lower
chromosphere temperature structure, especially for cooler atmospheres, such as
sunspots.

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The categories of this paper are: hep-lat
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The categories of this paper are: alg-geom
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The categories of this paper are: funct-an
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The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-ex
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The categories of this paper are: nucl-th
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The categories of this paper are: physics
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The categories of this paper are: bayes-an
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The categories of this paper are: eess
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The categories of this paper are: math
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The categories of this paper are: adap-org
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The categories of this paper are: quant-ph
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The categories of this paper are: cs