2002AJ....124..977C

Using photometric data from the Two Micron All Sky Survey Second Incremental Release Point Source Catalog, we constructed K_s versus J-K_s color-magnitude diagrams (CMDs) of Galactic globular clusters (GGCs) for which the JK_s photometric data have been made available up to now. On the CMDs of 13 GGCs, we identified red giant branch bump features and derived luminosities of bumps in K_s(K^Bump_s) and in M_Ks(M^Bump_Ks) for 11 of them. We reconfirm the relation between M^Bump_Ks and metallicity [Fe/H]_CG97 or [M/H], such that the luminosity of bump becomes brighter as metallicity [Fe/H]_CG97 or [M/H] decreases. This result is similar to that obtained by Ferraro et al. (published in 1999) for the relation between M^Bump_V and [M/H] based on observations of 47 GGCs that were conducted in the optical region (V vs. B-V CMDs). Our results show the same trend as those found by Ferraro et al. (published in 2000) for the relations between M^Bump_K and metallicity [Fe/H]_CG97 and [M/H] derived from observations of eight GGCs in the same near-infrared region (K vs. J-K CMDs). Combining with the 2000 data of Ferraro et al., we derive a robust relation for the metal-dependent luminosities of the bumps.