A Volume-Limited Survey of mCP Stars Within 100pc I: Fundamental Parameters and Chemical Abundances. (arXiv:1811.05633v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Sikora_J/0/1/0/all/0/1">J. Sikora</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wade_G/0/1/0/all/0/1">G. A. Wade</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Power_J/0/1/0/all/0/1">J. Power</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Neiner_C/0/1/0/all/0/1">C. Neiner</a>
We present the first results of a volume-limited survey of main sequence (MS)
magnetic chemically peculiar (mCP) stars. The sample consists of all identified
intermediate-mass MS stars (mCP and non-mCP) within a heliocentric distance of
$100,{rm pc}$ as determined using Hipparcos parallaxes. The two populations
are compared in order to determine the unique properties that allow a small
fraction of MS stars with masses $gtrsim1.4,M_odot$ to host strong, large
scale magnetic fields. A total of 52 confirmed mCP stars are identified using
published magnetic, spectroscopic, and photometric observations along with
archived and newly obtained spectropolarimetric (Stokes $V$) observations. We
derive the fundamental parameters (effective temperatures, luminosities,
masses, and evolutionary states) of the mCP and non-mCP populations using
homogeneous analyses. A detailed analysis of the mCP stars is performed using
the {sc llmodels} code, which allows observed spectral energy distributions to
be modeled while incorporating chemical peculiarities and magnetic fields. The
surface gravities and mean chemical abundances are derived by modelling
averaged spectra using the {sc gssp} and {sc zeeman} spectral synthesis
codes. Masses and stellar ages are derived using modern, densely calculated
evolutionary model grids. We confirm a number of previously reported
evolutionary properties associated with mCP stars including a conspicuously
high incidence of middle-aged MS stars with respect to the non-mCP subsample;
the incidence of mCP stars is found to sharply increase with mass from
$0.3$~per~cent at $1.5,M_odot$ to $approx11$~per~cent at $3.8,M_odot$.
Finally, we identify clear trends in the mean photospheric chemical abundances
with stellar age.
We present the first results of a volume-limited survey of main sequence (MS)
magnetic chemically peculiar (mCP) stars. The sample consists of all identified
intermediate-mass MS stars (mCP and non-mCP) within a heliocentric distance of
$100,{rm pc}$ as determined using Hipparcos parallaxes. The two populations
are compared in order to determine the unique properties that allow a small
fraction of MS stars with masses $gtrsim1.4,M_odot$ to host strong, large
scale magnetic fields. A total of 52 confirmed mCP stars are identified using
published magnetic, spectroscopic, and photometric observations along with
archived and newly obtained spectropolarimetric (Stokes $V$) observations. We
derive the fundamental parameters (effective temperatures, luminosities,
masses, and evolutionary states) of the mCP and non-mCP populations using
homogeneous analyses. A detailed analysis of the mCP stars is performed using
the {sc llmodels} code, which allows observed spectral energy distributions to
be modeled while incorporating chemical peculiarities and magnetic fields. The
surface gravities and mean chemical abundances are derived by modelling
averaged spectra using the {sc gssp} and {sc zeeman} spectral synthesis
codes. Masses and stellar ages are derived using modern, densely calculated
evolutionary model grids. We confirm a number of previously reported
evolutionary properties associated with mCP stars including a conspicuously
high incidence of middle-aged MS stars with respect to the non-mCP subsample;
the incidence of mCP stars is found to sharply increase with mass from
$0.3$~per~cent at $1.5,M_odot$ to $approx11$~per~cent at $3.8,M_odot$.
Finally, we identify clear trends in the mean photospheric chemical abundances
with stellar age.
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