相关论文: Carbon in the Draco Dwarf Spheroidal Galaxy

We report the detection, from observations using the James Clerk Maxwell Telescope, of CO J $=$ 3$\to$ 2 transition lines in six carbon stars, selected as members of the Galactic Halo and having similar infrared colors. Just one Halo star…

Classical chemical analyses may be affected by systematic errors that would cause observed abundance differences between dwarfs and giants. For some elements, however, the abundance difference could be real. We address the issue by…

High resolution, high S/N spectra have been obtained for a sample of 90 F and G main-sequence disk stars covering the metallicity range -1.0 < [Fe/H] < +0.1, and have been analysed in a parallel way to the work of Edvardsson et al. (1993).…

We determine relative abundance ratios for the neutron-capture elements Zr, La, Ce, Nd, and Eu for a sample of 27 Galactic dwarf stars with -1.5 < [Fe/H] <-0.8. We also measure the iron-peak element Sc. These stars separate into three…

We present the analysis of the FLAMES dataset targeting the central 25 arcmin region of the Sextans dSph. This dataset is the third major part of the high resolution spectroscopic section of the ESO large program 171.B-0588(A) obtained by…

[ABRIDGED] We have determined carbon abundances for 51 dwarf stars and manganese abundances for 95 dwarf stars in two distinct and well defined stellar populations - the Galactic thin and thick disks. As these two populations have different…

We present chemical abundances in a sample of luminous cool stars located within 30 pc of the Galactic Center. Abundances of carbon, nitrogen, oxygen, calcium, and iron were derived from high-resolution infrared spectra in the H- and…

We present abundances of several light, alpha, Fe-peak, and neutron-capture elements for 66 red giant branch (RGB) stars in the Galactic globular cluster Omega Centauri. Our observations lie in the range 12.0<V<13.5 and focus on the…

We measured $^{35}$Cl abundances in 52 M giants with metallicities between -0.5 $<$ [Fe/H] $<$ 0.12. Abundances and atmospheric parameters were derived using infrared spectra from CSHELL on the IRTF and from optical echelle spectra. We…

We have used the ACS camera on HST to obtain (V,I) photometry for 5300 red-giant stars in the halo of the dominant Leo-group member NGC 3379, a galaxy usually regarded as a classic normal giant elliptical. We use this sample of stars to…

We present measurements of Fe, Mg, Si, Ca, and Ti abundances for 388 radial velocity member stars in the Sculptor dwarf spheroidal galaxy (dSph), a satellite of the Milky Way. This is the largest sample of individual alpha element (Mg, Si,…

Ultra-faint dwarf galaxies recently discovered around the Milky Way (MW) contain extremely metal-poor stars, and might represent the building blocks of low-metallicity components of the MW. Among them, the Bo\"otes I dwarf spheroidal galaxy…

We present high-resolution UES spectra of the quasar PHL 957 obtained for studying the foreground Damped Ly-alpha galaxy at z=2.309. Measurements of absorption lines lead to accurate abundance determinations of Fe, S and N which complement…

Spectroscopic abundance determinations for stars spanning a Hubble time in age are necessary in order to unambiguously determine the evolutionary histories of galaxies. Using FORS1 in Multi-Object Spectroscopy mode on ANTU (UT1) at the…

Aim: We establish the mean metallicity from high-resolution spectroscopy for the recently found dwarf spheroidal galaxy Bootes I and test whether it is a common feature for ultra-faint dwarf spheroidal galaxies to show signs of…

In the framework of an ESO Large Programme high quality spectra of 70 very metal-poor dwarfs and giants were obtained with the VLT-UVES combination. This paper reports the detailed analyses of the 35 giants of the sample. At the exception…

We have performed accurate iron abundance measurements for 44 red giants (RGs) in the Carina dwarf spheroidal (dSph) galaxy. We used archival, high-resolution spectra (R~38,000) collected with UVES at ESO/VLT either in slit mode (5) or in…

An abundance analysis is reported of 58 K giants identified by Famaey et al. (2005) as highly probable members of the Hercules stream selected from stars north of the celestial equator in the Hipparcos catalogue. The giants have…

A search of more than 3,000 square degrees of high latitude sky by the Sloan Digital Sky Survey has yielded 251 faint high-latitude carbon stars (FHLCs), the large majority previously uncataloged. We present homogeneous spectroscopy,…

From ESO VLT/FLAMES/GIRAFFE spectra, abundance measurements of Zn have been made in $\approx$100 individual red giant branch (RGB) stars in the Sculptor dwarf spheroidal galaxy. This is the largest sample of individual Zn abundance…