A systematic aging method I: HII regions D118 and D119 in NGC 300. (arXiv:2004.02883v1 [astro-ph.SR])

A systematic aging method I: HII regions D118 and D119 in NGC 300. (arXiv:2004.02883v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Stevance_H/0/1/0/all/0/1">H.F. Stevance</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eldridge_J/0/1/0/all/0/1">J.J. Eldridge</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McLeod_A/0/1/0/all/0/1">A. McLeod</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stanway_E/0/1/0/all/0/1">E. R. Stanway</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chrimes_A/0/1/0/all/0/1">A. A. Chrimes</a>

Accurately determining the age of H,{ii} regions and the stars they host is
as important as it is challenging. Historically the most popular method has
been isochrone fitting to Hertzsprung-Russell Diagrams or Colour-Magnitude
Diagrams. Here we introduce a different method for age determination using
BPASS and hoki. We infer the most likely ages of the regions D118 and D119 NGC
300 to be log(age/years)=6.86$^{0.05}_{0.16}$ and we also deduce stellar mass
and number counts by comparison with the BPASS models. We compare how our
binary and single star models perform and find that the latter are unable to
predict 20 per cent ($pm$ 10 per cent) of our sample. We also discuss how
results obtained from isochrone fitting would differ. We conclude that ages
could be underestimated by ~0.2 dex and that the limitations of the isochrone
method is not solely due to the lack of binary stars. We propose that the
method presented here is more reliable and more widely applicable since it can
be used on smaller samples. Alongside this study, we release new hoki features
to allow easy implementation of this method.

Accurately determining the age of H,{ii} regions and the stars they host is
as important as it is challenging. Historically the most popular method has
been isochrone fitting to Hertzsprung-Russell Diagrams or Colour-Magnitude
Diagrams. Here we introduce a different method for age determination using
BPASS and hoki. We infer the most likely ages of the regions D118 and D119 NGC
300 to be log(age/years)=6.86$^{0.05}_{0.16}$ and we also deduce stellar mass
and number counts by comparison with the BPASS models. We compare how our
binary and single star models perform and find that the latter are unable to
predict 20 per cent ($pm$ 10 per cent) of our sample. We also discuss how
results obtained from isochrone fitting would differ. We conclude that ages
could be underestimated by ~0.2 dex and that the limitations of the isochrone
method is not solely due to the lack of binary stars. We propose that the
method presented here is more reliable and more widely applicable since it can
be used on smaller samples. Alongside this study, we release new hoki features
to allow easy implementation of this method.

http://arxiv.org/icons/sfx.gif

Comments are closed.