Related papers: Stellar populations in the Phoenix dwarf galaxy
The flux excess of elliptical galaxies in the far-ultraviolet can be reproduced by population synthesis models when accounting for the population of old hot helium-burning subdwarf stars. This has been achieved by Han and coworkers through…
We present homogeneous age determinations for a large sample of 55 Galactic globular clusters, which constitute about 30% of the total Galactic population. A study of their age distribution reveals that all clusters from the most metal poor…
We performed a uniform and detailed analysis of 1112 high-resolution spectra of FGK dwarfs obtained with the HARPS spectrograph at the ESO 3.6 m telescope (La Silla, Chile). Most stars have effective temperatures 4700 K < Teff < 6300 K and…
In a pioneering effort, Preston et al. reported that the colors of blue horizontal-branch (BHB) stars in the halo of the Galaxy shift with distance, from regions near the Galactic center to about 12 kpc away, and interpreted this as a…
A new moving group comprising at least four Blue Horizontal Branch (BHB) stars is identified at (l,b) = (65 deg, 48 deg). The horizontal branch at g0=18.9 magnitude implies a distance of 50 kpc from the Sun. The heliocentric radial velocity…
We investigate the resolved stellar content of early-type dwarf galaxies in the CenA group, in order to estimate the fraction of their intermediate-age populations. We use near-infrared photometric data taken with the VLT/ISAAC instrument,…
We study the ages of $\alpha$-rich and $\alpha$-poor stars in the halo using a sample of F and G dwarfs from the Sloan Digital Sky Survey (SDSS). To separate stars based on [$\alpha$/Fe], we have developed a new semi-empirical…
We exploit the [Mg/Mn]-[Al/Fe] chemical abundance plane to help identify nearby halo stars in the 14th data release from the APOGEE survey that have been accreted on to the Milky Way. Applying a Gaussian Mixture Model, we find a `blob' of…
Sagittarius (Sgr) is a massive disrupted dwarf spheroidal galaxy in the Milky Way halo that has undergone several stripping events. Previous chemical studies were restricted mainly to a few, metal- rich ([Fe/H]~ -1) stars that suggested a…
We derive the optical luminosity, colors, and ratios of the blue and red helium burning (HeB) stellar populations from archival Hubble Space Telescope observations of nineteen starburst dwarf galaxies and compare them with theoretical…
We present a new derivation of the star formation history (SFH) of the dSph galaxy Fornax in two central regions, characterised by unprecedented precision and age resolution. It reveals that star formation has proceeded in sharp bursts…
Based on high-resolution spectra obtained during gravitational microlensing events we present a detailed elemental abundance analysis of 32 dwarf and subgiant stars in the Galactic bulge. [ABRIDGED], we now have 58 microlensed bulge dwarfs…
Studying the stellar populations in the outskirts of spiral galaxies can provide important constraints on their structure, formation, and evolution. To that end, we present VI photometry obtained with the Advanced Camera for Surveys for…
We have extended the study of the young star clusters observed in the merger remnant galaxy NGC 7252 by obtaining K band photometry for these clusters. Our K band data significantly complement the optical photometry and spectroscopy in the…
Early-type dwarf galaxies are not simply featureless, old objects, but were found to be much more diverse, hosting substructures and a variety of stellar population properties. To explore the stellar content of faint early-type galaxies,…
If the stellar halos of disk galaxies are built up from the disruption of dwarf galaxies, models predict highly structured variations in the stellar populations within these halos. We test this prediction by studying the ratio of blue…
We present a comprehensive chemical abundance analysis of five red giants and two horizontal branch (HB) stars towards the southern Galactic bulge, at (l,b)$\sim$(0$^{\rm o}$,-11$^{\rm o}$). Based on high-resolution spectroscopy obtained…
We present a study on the stellar populations and stellar ages of sub-sample of far-infrared AGN and non-AGN green valley analysed in Mahoro et al. (2017,2019) at 0.6 < z < 1.0 using the data from the COSMOS field. We used long-slit…
The study of stellar populations in early-type galaxies in different environments is a powerful tool for constraining their star formation histories. This study has been traditionally restricted to the optical range, where dwarfs around the…
Surface Brightness Fluctuations (SBF) can provide useful information about the unresolved stellar content of early-type galaxies and spiral bulges. The absolute SBF magnitude Mbar in a given passband depends on the properties of the stellar…