Reconciling the galactic bulge turnoff age discrepancy with enhanced helium enrichment
We show that the factor 2 discrepancy between spectroscopic and photometric age determinations of the Galactic bulge main-sequence turnoff can be naturally explained by positing an elevated helium enrichment for the bulge relative to that assumed by standard isochrones. Helium enhancement relative to standard isochrones is confirmed at the 2.3σ level. We obtain an upper bound on the helium enrichment for the metal-rich ([Fe/H] +0.30) stars of ΔY +0.11 relative to canonical expectations, given...[Show more]
|Collections||ANU Research Publications|
|Source:||Astrophysical Journal Letters|
|01_Nataf_Reconciling_the_galactic_bulge_2012.pdf||598.7 kB||Adobe PDF|
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