Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Narrowest M-dwarf Line Profiles and the Rotation-Activity Connection
  at Very Slow Rotation   The rotation-activity connection explains stellar activity in terms of
rotation and convective overturn time. It is well established in stars of
spectral types F--K and in M-type stars of young clusters. It is not
established in field M-dwarfs, because they rotate very slowly, and detecting
rotation periods or rotational line broadening is a challenge. In field
M-dwarfs, saturation sets in below v_rot = 5 km/s, hence they are expected to
populate the non-saturated part of the rotation-activity connection. This work
for the first time shows intrinsically resolved spectral lines of slowly
rotating M-dwarfs and makes a first comparison to estimates of convective
velocities. By measuring rotation velocities in a sample of mostly inactive
M-dwarfs, the unsaturated part of the rotation-activity connection is followed
into the regime of very low activity. Spectra of ten M-dwarfs are taken at a
resolving power of R = 200 000 in the molecular FeH absorption band. The
intrinsically narrow lines are compared to model calculations and rotational
broadening is measured. In one star, an upper limit of vsini = 1 km/s was
found, significant rotation was detected in the other nine objects. All
inactive stars show rotation below or equal to 2 km/s. In the two active stars
AD Leo and YZ CMi, rotation velocities are found to be 40-50% below the results
from earlier studies. The rotation activity connection holds in field early-M
stars, too. Activity and rotation velocities of the sample stars are well in
agreement with the relation found in earlier and younger stars. The intrinsic
absorption profiles of molecular FeH lines are consistent with calculations
from atomic Fe lines. Investigation of FeH line profiles is a very promising
tool to measure convection patterns at the surfaces of M-stars.

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The categories of this paper are: supr-con
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The categories of this paper are: econ
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The categories of this paper are: math
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: funct-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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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: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: q-alg
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The categories of this paper are: cs
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The categories of this paper are: math-ph