Dienstag, 5. November 2013

APOGEE: stellar masses from astroseismology --> ages <--> abundances

Just took a quick look at the fabulous ASCAP results:
they have beautiful masses for a whole bunch of giants with [Fe/H] and
[alpha/Fe] ; they list evolutionary phase and masses;
given the abundances this translates / should translate into ages (e.g. Padova isochrones).

Next time I have a minute, I should just plot t_age = f( [Fe/H], [a/Fe] );
and ask Marc P. why the ages are not explicitly listed.


Some notes (June 2014) after Marie Martig's trials and tribulations:

What we get reliably is:
1) log g; then 2) mass (where Teff comes into the scaling)
we have modest faith in [Fe/H], and something seems screwy with
T_eff (let's get dereddened colors from PS1 or the "amateur survey").

Marie's proposal:
let's rely on log-g and masses only; but even that relationship relies somewhat on
the abundances...

need to discuss age-priors

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