Metallicities, distances, and kinematics of the stellar populations of the bulge and inner disk of the Milky Way galaxy

I examine several questions in the study of the stellar populations of the bulge and inner disk of the Milky Way galaxy. I obtain JHK photometry of Baade's Window (BW), {dollar}(ell,b)=({lcub}+{rcub}1.0spcirc, {lcub}-{rcub}3.9spcirc){dollar} and another minor-axis field at {dollar}(ell,b)=(0spcirc, {lcub}-{rcub}6spcirc).{dollar} I supplement this photometry with published single-channel photometry and construct a K-band luminosity function spanning {dollar}5.5le Kle16.5.{dollar} Using {dollar}(J-K)sb0, K{dollar} color-magnitude diagrams of the fields and the relationship found previously between the slope of the upper giant branch and average (Fe/H), I derive {dollar}langlelbrack{dollar}Fe/H) {dollar}rangle={lcub}-{rcub}0.28pm0.16{dollar} dex for BW and {dollar}langlelbrack{dollar}Fe/H) {dollar}rangle={lcub}-{rcub}0.65pm0.18{dollar} dex for the second field. With published photometry for 6 additional minor-axis fields in the range {dollar}{lcub}-{rcub}12spcircle ble{lcub}-{rcub}3spcirc,{dollar} I derive {dollar}langlelbrack{dollar}Fe/H{dollar}rbrackrangle{dollar} values and determine the gradient in {dollar}langlelbrack{dollar}Fe/H{dollar}rbrackrangle{dollar} along the minor axis to be {dollar}-{dollar}0.060 {dollar}pm{dollar} 0.033 dex deg{dollar}sp{lcub}-1{rcub}{dollar} {dollar}({lcub}-{rcub}0.43pm0.21{dollar} dex Kpc{dollar}sp{lcub}-1{rcub}).{dollar} Using the luminosity function and the {dollar}Rspprime{dollar} method, I derive average helium abundance for BW and find {dollar}Y=0.27pm0.03.{dollar} This value in combination with the {dollar}langlelbrack{dollar}Fe/H{dollar}rbrackrangle{dollar} gives {dollar}Delta Y/Delta Z=3.3pm1.3{dollar} for the population. I also obtain VI photometry and medium resolution optical spectra for stars in four fields located symmetrically about the minor axis at {dollar}b={lcub}-{rcub}6spcirc.{dollar} The outer set of fields are located at {dollar}ell={lcub}pm{rcub}24spcirc{dollar} and the inner set at {dollar}ell={lcub}pm{rcub}8spcirc.{dollar} I measure radial velocities and strengths of absorption-line indices, and derive average reddening to each field, individual (Fe/H), and photometric parallax to each star, and mean azimuthal rotation velocity and velocity dispersion for each field. I find that stars are not strongly peaked at the tangent point along each line-of-sight. I see the established correlation between decreasing velocity dispersion with increasing (Fe/H), but also find that both velocity dispersion and (Fe/H) are a function of distance. Thus, I conclude that the correlation between velocity dispersion and (Fe/H) results from seeing multiple populations superposed along the line-of-sight. Further I find that the velocities of the inner disk are not symmetric about the minor axis, implying the possibility of a bar-like structure in the inner disk similar to the one found in the galactic bulge. However, I find no clear kinematical evidence either for or against a barred bulge.