We present long-slit spectroscopy of the elliptical galaxy M32 , obtained with the 8-m Subaru telescope at Mauna Kea , the 1.5-m Tillinghast telescope at the F. L. Whipple Observatory , and the 4-m Mayall telescope at the Kitt Peak National Observatory .
The spectra cover the Lick index red spectral region as well as higher order Balmer lines in the blue .
Spectra have been taken with the slit off-set from the nucleus to avoid scattered light contamination from the bright nucleus of M32 .
An analysis of numerous absorption features , particularly involving the H \gamma and H \beta Balmer lines , reveals that systematic radial trends are evident in the integrated spectrum of M32 .
Population synthesis models indicate a radial change in both the age and chemical composition of the light-weighted mean stellar population in M32 , from the nucleus out to 33˝ , i.e. , approximately 1.0 effective radius , R _ { e } .
Specifically , the light-weighted mean stellar population at 1 R _ { e } is older , by \sim 3 Gyr , and more metal-poor , by \sim - 0.25 dex in [ Fe/H ] , than the central value of \sim 4 Gyr and [ Fe/H ] \sim 0.0 .
We show that this apparent population trend can not be attributed to a varying contribution from either hot stars or emission line contamination .
The increase in age and decrease in metal-abundance with radius are sufficiently well-matched to explain the flat radial color profiles previously observed in M32 .
In addition , the ratio of Mg to Fe abundance , [ Mg/Fe ] , increases from \sim - 0.25 in the nucleus to \sim - 0.08 at 1 R _ { e } .
Finally , we find spuriously pronounced line strength gradients in the Mayall data that are an artifact of scattered light from the bright nucleus .
Scattered light issues may explain the lack of consistency among previously published studies of radial line strength gradients in M32 .