相关论文: UVES observations of the Canis Major overdensity

We present detailed Chemical abundances for 12 stars in the Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph) and 3 in the Canis Mayor Overdensity (CMa), based on UVES spectra. Sgr dSph stars present high metallicity ([Fe/H] between -1 and 0)…

We have carried out a big FLAMES survey of 10 Galactic open clusters aiming at different goals. One of them is the determination of chemical abundances, in order to put constraints on the radial metallicity gradient in the disk and its…

We present a study of accurate stellar parameters and iron abundances for 39 giants and 16 dwarfs in the 13 open clusters IC2714, IC4651, IC4756, NGC2360, NGC2423, NGC2447 (M93), NGC2539, NGC2682 (M67), NGC3114, NGC3680, NGC4349, NGC5822,…

The recently-discovered stellar system in Canis Major is analysed using He-burning Red Clump stars as tracers. Canis Major turns out to be the strongest and most spatially confined overdensity of the whole Galactic Disc, both in terms of…

Metal-rich globular clusters trace the formation of bulges. Abundance ratios in the metal-rich globular clusters such as NGC 6553 can constrain the formation timescale of the Galactic bulge. The purpose of this study is determine the…

We present metallicities, [Fe/H], and elemental abundance ratios, [X/Fe], for a sample of 24 Cepheids in the outer Galactic disk. The sample have Galactocentric distances covering 12 < R_GC (kpc) < 17.2 making them the most distant Galactic…

We measure chemical abundance ratios and radial velocities in four massive (i.e., young) [alpha/Fe]-rich red giant stars using high-resolution high-S/N spectra from ESPaDOnS fed by Gemini-GRACES. Our differential analysis ensures that our…

The advent of the new class 8 meters telescopes allows for the first time the detailed study of numerous stars of galaxies other than our own. The Large Magellanic Cloud is one of the most interesting targets due to its proximity and its…

In response to criticism by Momany et al. (2004), that the recently-identified Canis Major (CMa) overdensity could be simply explained by the Galactic warp, we present proof of the existence of a stellar population in the direction of CMa…

We present a study of the chemical abundances of Solar neighbourhood stars associated to dynamical structures in the Milky Way's (thick) disk. These stars were identified as overdensity in the eccentricity range 0.3< ecc < 0.5 in the…

We performed a photometric multicolor survey of the core of the Canis Major over-density at l 244, -8.0, reaching V = 22 and covering 0.3 x 1 degree. The main aim is to unravel the complex mixture of stellar populations toward this Galactic…

Proper-motion, star counts and photometric catalog simulations are used to explain the detected stellar over-density in the region of Canis Major (CMa), claimed to be the core of a disrupted dwarf galaxy (Martin et al. 2004, Bellazzini et…

The outer parts of the Milky Way disk are believed to be one of the main arenas where the accretion of external material in the form of dwarf galaxies and subsequent formation of streams is taking place. The Monoceros stream and the Canis…

We summarize radial velocity studies of selected stars in the old, distant clusters Berkeley 20, Berkeley 21, NGC 2141, Berkeley 29, and Berkeley 31. Three members of M67 were observed similarly, and those velocities compare extremely well…

NGC 6388 is one of the most massive Galactic globular clusters (GC) and it is an old, metal-rich, Galactic bulge cluster. By exploiting previous spectroscopic observations we were able to bypass the uncertainties in membership related to…

We have measured the elemental abundances of 68 Galactic and Magellanic Cepheids from FEROS and UVES high-resolution and high signal-to-noise spectra in order to establish the influence of the chemical composition on the properties of these…

We present a study of the stellar parameters and iron abundances of 18 giant stars in 6 open clusters. The analysis was based on high-resolution and high-S/N spectra obtained with the UVES spectrograph (VLT-UT2). The results complement our…

We present a first deep colour-magnitude diagram of the putative central region (0.5 deg x 0.5 deg) of the Canis Major stellar over-density (l,b)=(240,-8) found by Martin et al. (2004), which has been proposed as the remnant of a dwarf…

We present a detailed chemical abundance analysis of the brightest star in the ultra-faint dwarf (UFD) galaxy candidate Cetus II from high-resolution Magellan/MIKE spectra. For this star, DES J011740.53-173053, abundances or upper limits of…

We present the abundance analysis of 82 red giant branch stars in the dense, metal-poor globular cluster NGC 6093 (M 80), the largest sample of stars analyzed in this way for this cluster. From high resolution UVES spectra of 14 stars and…