Related papers: A Possible Relic Star Cluster in the Sextans Dwarf…
We present a study of the old globular cluster (GC) population of the dwarf irregular galaxy NGC 1427A using multi-wavelength VLT observations in U, B, V, I, H_alpha, J, H, and Ks bands under excellent observing conditions. We applied color…
We present 23 candidate X-ray binaries with luminosities down to 1.8x10^36 erg/s, in the nearby starburst galaxy NGC 4449, from observations totaling 105 ksec taken with the ACIS-S instrument on the Chandra Space Telescope. We determine…
We present the result of a photometric and Keck-LRIS spectroscopic study of dwarf galaxies in the core of the Perseus Cluster, down to a magnitude of M_B = -12.5. Spectra were obtained for twenty-three dwarf-galaxy candidates, from which we…
We report the discovery of a young massive stellar cluster embedded in an extended HII region, invisible at optical wavelengths where the extinction is $A_V \approx 28$ magnitudes, associated with the IRAS source 16177-5018. $J, H$ and…
We present the results of a search for brown dwarfs (BDs) and very low mass (VLM) stars in the 625 Myr-old, metal-rich ([Fe/H]=0.14) Hyades cluster. We performed a deep (I=23, z=22.5) photometric survey over 16 deg$^2$ around the cluster…
We have used public data from the Next Generation Virgo Survey (NGVS) to investigate the dwarf galaxy population of the Virgo cluster beyond what has previously been discovered. We initially mask and smooth the data, and then use the object…
CCD vby Stroemgren photometry of a statistically complete sample of red giants and stars in the main sequence turn-off region in omega Centauri has been used to analyse the apparently complex star formation history of this cluster. From the…
We present first results of a large photometric survey devoted to study the star formation history of the Sagittarius dwarf spheroidal galaxy (Sgr dSph). Three wide strips (9 X 35 arcmin^2) located at l~5 and b=-16, -14, -12 have been…
Using two HST/ACS data-sets that are separated by ~2 years has allowed us to derive the relative proper-motion for the Sagittarius dwarf irregular (SagDIG) and reduce the heavy foreground Galactic contamination. The proper-motion…
We have obtained V and I-band photometry for about 17500 stars in the field of the dwarf irregular galaxy NGC3109, located in the outskirts of the Local Group. The photometry allows us to study the stellar populations present inside and…
We report on the discovery of a new Milky Way companion stellar system located at (RA, Dec) = (22h10m43.15s, +14:56:58.8). The discovery was made using the eighth data release of SDSS after applying an automated method to search for…
We report on the detection of reddening toward z ~ 0.2 galaxy clusters. This is measured by correlating the Sloan Digital Sky Survey cluster and quasar catalogs and by comparing the photometric and spectroscopic properties of quasars behind…
We present the star cluster catalogs for 17 dwarf and irregular galaxies in the $HST$ Treasury Program "Legacy ExtraGalactic UV Survey" (LEGUS). Cluster identification and photometry in this subsample are similar to that of the entire LEGUS…
A detailed study of the Star Formation History of the Sgr dSph galaxy is performed through the analysis of the data from the Sagittarius Dwarf Galaxy Survey (SDGS; Bellazzini, Ferraro & Buonanno 1999). Accurate statistical decontamination…
This paper explores if, and to what an extent, the stellar populations of early type galaxies can be traced through the colour distribution of their globular cluster systems. The analysis, based on a galaxy sample from the Virgo ACS data,…
In this paper we study the underlying stellar population of a sample of 65 nearby early-type galaxies predominantly located in low density environments. Ages, metallicities and [alpha/Fe] ratios have been derived through the comparison of…
We present the metallicities and carbon abundances of four newly discovered metal-poor stars with $ -2.2 <$ [Fe/H] $< -1.6$ in the Sagittarius dwarf spheroidal galaxy. These stars were selected as metal-poor member candidates using a…
We study the young star cluster populations in 23 dwarf and irregular galaxies observed by the HST Legacy ExtraGalactic Ultraviolet Survey (LEGUS), and examine relationships between the ensemble properties of the cluster populations and…
We present a detailed study of the variable star population of Eridanus II (Eri II), an ultra-faint dwarf galaxy that lies close to the Milky Way virial radius. We analyze multi-epoch $g,r,i$ ground-based data from Goodman and the Dark…
We have undertaken a search for variable stars in the metal-rich globular cluster NGC 6441 using time-series BV photometry. The total number of variables found near NGC 6441 has been increased to ~104, with 48 new variables being found in…