Extended Data Fig. 4: Determining the age of the OP in Liller1.
From: A new class of fossil fragments from the hierarchical assembly of the Galactic bulge
The value of the χ2 parameter (see Section ‘Measuring the age of the old stellar population’ in Methods) is plotted as a function of the age of seven isochrones (with t=10, 11, 11.5, 12, 12.5, 13, 14 Gyr) computed for the quoted metallicity of the OP ([M/H]=−0.3). The minimum of the χ2 parameter suggests an age of 12 ± 1 Gyr for the OP of Liller 1.
