From Two Micron All Sky Survey infrared photometry, we find two red clump (RC) populations coexisting in fields toward the Galactic bulge at latitudes vertical bar b vertical bar > 5 degrees.5, ranging over similar to 13 degrees in longitude and 20 degrees in latitude. These RC peaks indicate two stellar populations separated by similar to 2.3 kpc; at (l, b) = (+1, -8) the two RCs are located at 6.5 and 8.8 +/- 0.2 kpc. The double-peaked RC is inconsistent with a tilted bar morphology. Most of our fields show the two RCs at roughly constant distance with longitude, also inconsistent with a tilted bar; however, an underlying bar may be present. Stellar densities in the two RCs change dramatically with longitude: on the positive longitude side the foreground RC is dominant, while the background RC dominates negative longitudes. A line connecting the maxima of the foreground and background populations is tilted to the line of sight by similar to 20 degrees +/- 4 degrees, similar to claims for the tilt of a Galactic bar. The distance between the two RCs decreases toward the Galactic plane; seen edge-on the bulge is X-shaped, resembling some extragalactic bulges and the results of N-body simulations. The center of this X is consistent with the distance to the Galactic center, although better agreement would occur if the bulge is 2-3 Gyr younger than 47 Tuc. Our observations may be understood if the two RC populations emanate, nearly tangentially, from the Galactic bar ends, in a funnel shape. Alternatively, the X, or double funnel, may continue to the Galactic center. From the Sun, this would appear peanut/box shaped, but X-shaped when viewed tangentially.

We present Fe, Si, and Ca abundances for 61 giants in Plaut's window (l = -1 degrees, b = -8.degrees 5) and Fe abundances for an additional 31 giants in a second, nearby field (l = 0 degrees, b = -8 degrees) derived from high-resolution (R approximate to 25,000) spectra obtained with the Blanco 4 m telescope and Hydra multifiber spectrograph. The median metallicity of red giant branch (RGB) stars in the Plaut's field is similar to 0.4 dex lower than those in Baade's window, and confirms the presence of an iron abundance gradient along the bulge minor axis. The full metallicity range of our (biased) RGB sample spans -1.5 < [Fe/H] < +0.3, which is similar to that found in other bulge fields. We also derive a photometric metallicity distribution function for RGB stars in the (l = -1 degrees, b = -8.degrees 5) field and find very good agreement with the spectroscopic metallicity distribution. The radial velocity (RV) and dispersion data for the bulge RGB stars are in agreement with previous results of the Bulge Radial Velocity Assay survey, and we find evidence for a decreasing velocity dispersion with increasing [Fe/H]. The [alpha/Fe] enhancement in Plaut field stars is nearly identical to that observed in Baade's window, and suggests that an [alpha/Fe] gradient does not exist between b = -4 degrees and -8 degrees. Additionally, a subset of our sample (23 stars) appears to be foreground red clump stars that are very metal rich, exhibit small metallicity and RV dispersions, and are enhanced in alpha elements. While these stars likely belong to the Galactic inner disk population, they exhibit [alpha/Fe] ratios that are enhanced above the thin and thick disk.

We present chemical abundances in three red giants and two turnoff (TO) stars in the metal-poor Galactic globular cluster (GC) NGC 6397 based on spectroscopy obtained with the Magellan Inamori Kyocera Echelle high-resolution spectrograph on the Magellan 6.5 m Clay telescope. Our results are based on a line-by-line differential abundance analysis relative to the well-studied red giant Arcturus and the Galactic halo field star Hip 66815. At a mean of -2.10 +/- 0.02 (stat.) +/-0.07 (sys.), the differential iron abundance is in good agreement with other studies in the literature based on gf-values. As in previous differential works we find a distinct departure from ionization equilibrium in that the abundances of Fe I and Fe II differ by similar to 0.1 dex, with opposite signs for the red giant branch (RGB) and TO stars. The alpha-element ratios are enhanced to 0.4 (RGB) and 0.3 dex (TO), respectively, and we also confirm strong variations in the O, Na, and Al/Fe abundance ratios. Accordingly, the light-element abundance patterns in one of the red giants can be attributed to pollution by an early generation of massive Type II supernovae. TO and RGB abundances are not significantly different, with the possible exception of Mg and Ti, which are, however, amplified by the patterns in one TO star additionally belonging to this early generation of GC stars. We discuss interrelations of these light elements as a function of the GC metallicity.

We analyzed the distribution of the red clump (RC) stars throughout the Galactic bulge using Two Micron All Sky Survey data. We mapped the position of the RC in 1 deg(2) fields within the area vertical bar l vertical bar <= 8 degrees.5 and 3 degrees.5 <= vertical bar b vertical bar <= 8 degrees.5, for a total of 170 deg(2). The single RC seen in the central area splits into two components at high Galactic longitudes in both hemispheres, produced by two structures at different distances along the same line of sight. The X-shape is clearly visible in the Z-X plane for longitudes close to the l = 0 degrees axis. Crude measurements of the space densities of RC stars in the bright and faint RC populations are consistent with the adopted RC distances, providing further supporting evidence that the X-structure is real, and that there is approximate front-back symmetry in our bulge fields. We conclude that the Milky Way bulge has an X-shaped structure within vertical bar l vertical bar| <= 2 degrees, seen almost edge-on with respect to the line of sight. Additional deep near-infrared photometry extending into the innermost bulge regions combined with spectroscopic data is needed in order to discriminate among the different possibilities that can cause the observed X-shaped structure.

We have now completed detailed abundance analyses of more than 100 stars selected as candidate extremely metal-poor stars with [Fe/H] < -3.0 dex. Of these 18 are below -3.3 dex on the scale of the First Stars VLT project led by Cayrel, and 57 are below -3.0 dex on that scale. Ignoring enhancement of carbon which ranges up to very large values, and two C-rich stars with very high N as well, there are 0 to 3 high or low strong outliers for each abundance ratio tested from Mg to Ni. The outliers have been checked and they are real. Ignoring the outliers, the dispersions are in most cases approximately consistent with the uncertainties, except those for [Sr/Fe] and [Ba/Fe], which are much larger. Approximately 6% of the sample are strong outliers in one or more elements between Mg and Ni. This rises to similar to 15% if minor outliers for these elements and strong outliers for Sr and Ba are included. There are 6 stars with extremely low [Sr/Fe] and [Ba/Fe], including one which has lower [Ba/H] than Draco 119, the star found by Fulbright, Rich & Castro to have the lowest such ratio known previously. There is one extreme r-process star.

We present chemical abundances for 27 elements ranging from oxygen to erbium in the metal-poor ([Fe/H] = -1.67) bulge red giant branch star 2MASS 18174532-3353235. The results are based on equivalent width and spectrum synthesis analyses of a high-resolution (R similar to 30,000) spectrum obtained with the Magellan-MIKE spectrograph. While the light (Z less than or similar to 30) element abundance patterns match those of similar metallicity bulge and halo stars, the strongly enhanced heavy element abundances are more similar to "r-II" halo stars (e. g., CS 22892-052) typically found at [Fe/H] less than or similar to -2.5. We find that the heaviest elements (Z >= 56) closely follow the scaled-solar r-process abundance pattern. We do not find evidence supporting significant s-process contributions; however, the intermediate mass elements (e.g., Y and Zr) appear to have been produced through a different process than the heaviest elements. The light and heavy element abundance patterns of 2MASS 18174532-3353235 are in good agreement with the more metal-poor r-process enhanced stars CS 22892-052 and BD + 17 degrees 3248. 2MASS 18174532-3353235 also shares many chemical characteristics with the similar metallicity but comparatively alpha-poor Ursa Minor dwarf galaxy giant COS 82. Interestingly, the Mo and Ru abundances of 2MASS 18174532-3353235 are also strongly enhanced and follow a similar trend recently found to be common in moderately metal-poor main-sequence turn-off halo stars.

Spectrum syntheses for three elements (Mg, Na and Eu) in high-resolution integrated light spectra of the Galactic globular clusters 47 Tuc, M3, M13, NGC 7006 and M15 are presented, along with calibration syntheses of the solar and Arcturus spectra. Iron abundances in the target clusters are also derived from integrated light equivalent width analyses. Line profiles in the spectra of these five globular clusters are well fitted after careful consideration of the atomic and molecular spectral features, providing levels of precision that are better than equivalent width analyses of the same integrated light spectra, and that are comparable to the precision in individual stellar analyses. The integrated light abundances from the 5528 and 5711 A Mg i lines, the 6154 and 6160 A Na i lines, and the 6645 A Eu ii line fall within the observed ranges from individual stars; however, these integrated light abundances do not always agree with the average literature abundances. Tests with the second parameter clusters M3, M13 and NGC 7006 show that assuming an incorrect horizontal branch morphology is likely to have only a small ( less than or similar to 0.06 dex) effect on these Mg, Na and Eu abundances. These tests therefore show that integrated light spectrum syntheses can be applied to unresolved globular clusters over a wide range of metallicities and horizontal branch morphologies. Such high precision in integrated light spectrum syntheses is valuable for interpreting the chemical abundances of globular cluster systems around other galaxies.

From detailed abundance analysis of >100 Hamburg/ESO candidate extremely metal-poor (EMP) stars we find 45 with [Fe/H] < -3.0 dex. We identify a heretofore unidentified group: Ca-deficient stars with sub-solar [Ca/Fe] ratios and the lowest neutron-capture abundances; the Ca-deficient group comprises similar to 10% of the sample, excluding Carbon stars. Our radial velocity distribution shows that the carbon-enhanced stars with no s-process enhancements, CEMP-no, and which do not show C-2 bands are not preferentially binary systems. Ignoring Carbon stars, approximately 15% of our sample are strong (>= 5 sigma) outliers in one or more elements between Mg and Ni; this rises to similar to 19% if very strong (>= 10 sigma) outliers for Sr and Ba are included. Examples include: HE0305-0554 with the lowest [Ba/H] known; HE1012-1540 and HE2323-0256, two (non-velocity variable) C-rich stars with very strong [Mg, Al/Fe] enhancements; and HE1226-1149, an extremely r-process rich star.

From chemical abundance analysis of stars in the Sagittarius dwarf spheroidal galaxy (Sgr), we conclude that the alpha-element deficiencies cannot be due to the Type Ia supernova (SN Ia) time-delay scenario of Tinsley. Instead, the evidence points to low [alpha/Fe] ratios resulting from an initial mass function (IMF) deficient in the highest mass stars. The critical evidence is the 0.4 dex deficiency of [O/Fe], [Mg/Fe], and other hydrostatic elements, contrasting with the normal trend of r-process [Eu/Fe] r with [Fe/H]. Supporting evidence comes from the hydrostatic element (O, Mg, Na, Al, Cu) [X/Fe] ratios, which are inconsistent with iron added to the Milky Way (MW) disk trends. Also, the ratio of hydrostatic to explosive (Si, Ca, Ti) element abundances suggests a relatively top-light IMF. Abundance similarities with the LMC, Fornax, and IC 1613 suggest that their a-element deficiencies also resulted from IMFs lacking the most massive SNe II. The top-light IMF, as well as the normal trend of r-process [Eu/Fe](r) with [Fe/H] in Sgr, indicates that massive SNe II (greater than or similar to 30M(circle dot)) are not major sources of r-process elements. High [La/Y] ratios, consistent with leaky-box chemical evolution, are confirmed but similar to 0.3 dex larger than theoretical asymptotic giant branch (AGB) predictions. This suggests that a substantial increase in the theoretical C-13 pocket in low-mass AGB stars is required. Sgr has the lowest [Rb/Zr] ratios known, consistent with pollution by low-mass (less than or similar to 2M(circle dot)) AGB stars near [Fe/H] = -0.6, likely resulting from leaky-box chemical evolution. The [Cu/O] trends in Sgr and the MW suggest that Cu yields increase with both metallicity and stellar mass, as expected from Cu production by the weak s-process in massive stars. Finally, we present an updated hyperfine splitting line list, an abundance analysis of Arcturus, and further develop our error analysis formalism.

Context. The Galactic bulge is a massive, old component of the Milky Way. It is known to host a bar, and it has recently been demonstrated to have a pronounced boxy/peanut structure in its outer region. Several independent studies suggest the presence of more than one stellar populations in the bulge, with different origins and a relative fraction changing across the bulge area.