Near-IR photometry of asymptotic giant branch stars in the dwarf elliptical galaxy NGC 147

Near-infrared $J, H$ and K' images were used to investigate the stellar contents of the asymptotic giant branch (AGB) population in the nearby dwarf elliptical galaxy NGC 147. The obtained $(K, J-K)$ and $(K, H-K)$ color–magnitude diagrams contain stars of AGB and red giant branch populations, where the former consists of a group of bright blue stars, a dominant population of M giant and a red C star population. We identified 91 AGB C stars in NGC 147 with the mean absolute magnitude and colors of $\langle M_K\rangle = -7.56$, $\langle(J-K)_0\rangle = 1.81$ and $\langle(H-K)_0\rangle = 0.74$. The estimated number ratio of C stars to M giant stars (C/M) is $0.16\pm0.02$. The estimated local C/M ratios of $0.14\pm 0.02$ for the inner region ($r70''$) indicate a weak radial gradient. The mean bolometric magnitude of 91 C stars in NGC 147 is $\langle M_{\rm bol}\rangle = -4.32\pm 0.49$. The bolometric luminosity function of M giant stars in NGC 147 extends up to $M_{\rm bol} = -5.8$ mag, and that of only C stars spans $-5.6