Related papers: A unique isolated dwarf spheroidal galaxy at D=1.9…
We present a quantitative star formation history of the nearby dwarf galaxy UGCA 92. This irregular dwarf is situated in the vicinity of the Local Group of galaxies in a zone of strong Galactic extinction (IC 342 group of galaxies). The…
We present Magellan/MIKE and Keck/HIRES high-resolution spectra of six red giant stars in the dwarf galaxy Segue 1. Including one additional Segue 1 star observed by Norris et al. (2010), high-resolution spectra have now been obtained for…
We present the star formation history of the extremely metal-poor dwarf galaxy DDO 68, based on our photometry with the Advanced Camera for Surveys. With a metallicity of only $12+\log(O/H)=7.15$ and a very isolated location, DDO 68 is one…
We present a study of the evolved stellar populations in the dwarf spheroidal galaxy Fornax based on JHK imaging photometry. The observations cover an 18.5x18.5 arcmin central area with a mosaic of NTT/SOFI images. Our data sample all the…
We present deep and wide V, I CCD photometry of Ursa Major I (UMa I) dwarf spheroidal galaxy (dSph) in Local Group. The images of the galaxy were taken by Subaru/Suprime-Cam wide field camera, covering a field of 34\arcmin $\times$…
The Draco dwarf spheroidal galaxy (dSph), with its apparent immense mass to light ratio and compact size, holds many clues to the nature of the enigmatic dark matter. Here we present deep photometric studies of this dwarf galaxy, undertaken…
We present new metallicity measurements for 298 individual red giant branch stars in eight of the least luminous dwarf spheroidal galaxies (dSphs) in the Milky Way (MW) system. Our technique is based on medium resolution Keck/DEIMOS…
We report the discovery of a new dwarf galaxy (NGC6503-d1) during the Subaru extended ultraviolet (XUV) disk survey. It is a likely companion of the spiral galaxy NGC6503. The resolved images, in B, V, R, i, and Halpha, show an irregular…
We present HST WFPC2 imaging of the nearby low-surface-brightness dwarf spheroidal galaxy ESO 410-G005, which has been resolved into stars for the first time. The resulting color-magnitude diagram for about 2500 stars shows a red giant…
We present new narrow-band (H$\alpha$ and [OIII]) imagings and optical spectrophotometry of HII regions for a gas-rich low surface brightness irregular galaxy, KKR 17. The central surface brightness of the galaxy is $\mu_0(B)$ = 24.15…
We predict the metallicity distribution of stars and the age-metallicity relation for 6 Dwarf Spheroidal (dSph) galaxies of the Local Group by means of a chemical evolution model which is able to reproduce several observed abundance ratios…
We present initial results from a wide field photometric survey of the Fornax dwarf spheroidal (dSph) galaxy. The focus here is on a small overdensity of stars located approximately 17 arcmin (670 pc in projection) from the centre of…
We present the results of a deep study of the isolated dwarf galaxies Andromeda XXVIII and Andromeda XXIX with Gemini/GMOS and Keck/DEIMOS. Both galaxies are shown to host old, metal-poor stellar populations with no detectable recent star…
Based on the observed paucity of the dwarf spheroidal (dSph) satellites of the Milky Way at small Galactocentric distances, we put forward the hypothesis that subsequent to the formation of the Milky Way and its satellites, those dSphs that…
Dwarf spheroidal (dSph) galaxies present an evolutionary puzzle that we explore in 40 early- and late-type dwarfs in the Local Group and nearby field. Although dSphs formed stars over extended periods, today all but one are free of…
Growing evidence supports an unusual elemental feature appearing in nearby dwarf galaxies, especially dwarf spheroidals (dSphs), indicating a key process of galaxy evolution that is different from that of the Galaxy. In addition to the…
We present the star formation history and chemical evolution of the Sextans dSph dwarf galaxy as a function of galactocentric distance. We derive these from the $VI$ photometry of stars in the $42' \times 28'$ field using the SMART model…
(abridged) We provide Ks photometry for roughly 39,000 stars and H-band photometry for about 11,000 stars within a field of about 40"x40", centred on Sgr A*. In addition, we provide Ks photometry of about 3,000 stars in a very deep central…
Dwarf spheroidal galaxies (dSphs) have been extensively investigated in the Local Group, but their low luminosity and surface brightness make similar work in more distant galaxy groups challenging. Modern instrumentation unlocks the…
We have found evidence for the presence of two distinct ancient stellar components (both geq 10 Gyr old) in the Sculptor dwarf spheroidal galaxy. We used the ESO Wide Field Imager (WFI) in conjunction with the VLT/FLAMES spectrograph to…