相关论文: The stellar content of the isolated transition dwa…
We present deep BVI CCD photometry of the stars in the dwarf galaxy DDO 210. The color-magnitude diagrams of DDO 210 show a well-defined red giant branch (RGB) and a blue plume. The tip of the RGB is found to be at I_TRGB = 20.95 +/- 0.10…
The spatial distribution of stellar populations, the star formation history, and other properties of the dIrr galaxy DDO 190 have been analyzed using color--magnitude diagrams (CMDs) of about 3900 resolved stars and the Ha fluxes of HII…
We present deep, wide-field g and r photometry of the transition type dwarf galaxy Leo T, obtained with the blue arm of the Large Binocular Telescope. The data confirm the presence of both very young (<1 Gyr) as well as much older (>5 Gyr)…
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 results from a wide-area photometric survey of the Phoenix dwarf galaxy, one of the rare dwarf irregular/ dwarf spheroidal transition type galaxies (dTs) of the Local Group (LG). These objects offer the opportunity to study the…
We have probed the pulsating variable star content of the isolated Local Group dwarf galaxy, DDO210 (Aquarius), using archival Advanced Camera for Surveys/$Hubble$ $Space$ $Telescope$ imaging in the F475W and F814W passbands. We find a…
We carried out a wide-field V, I imaging survey of the Local Group dwarf spheroidal galaxy Leo II using the Subaru Prime Focus Camera on the 8.2-m Subaru Telescope. The survey covered an area of 26.67 x 26.67 arcmin^2, far beyond the tidal…
(abridged) We present B,V,I CCD photometry of about 40000 stars in four regions of the Fornax dSph. Using the resultant CMDs, many already known age-tracers are investigated, and new CMD features are also detected: we show that blue HB…
DDO 68 is the second most metal-poor star-forming galaxy (12+log(O/H)=7.14). Its peculiar optical morphology and the data on its HI distribution and kinematics indicate the merger origin. We use the photometry of the SDSS u,g,r,i images of…
We present resolved-star VI photometry of the Local Group dwarf irregular galaxy IC1613 reaching I~23.5, obtained with the wide-field camera at the 2.5m Isaac Newton Telescope. A fit to the stellar density distribution shows an exponential…
Observations with the Hubble Space Telescope unexpectedly revealed that the dwarf galaxy ESO 006-001 is a near neighbor to the Local Group at a distance of 2.70 +- 0.11 Mpc. The stellar population in the galaxy is well resolved into…
We have traced the spatial distributions of intermediate-age and old stars in nine dwarf galaxies in the distant parts of the Local Group, using multi-epoch 3.6 and 4.5 micron data from the DUST in Nearby Galaxies with Spitzer (DUSTiNGS)…
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 a study of the variation of spatial structure of stellar populations within dwarf galaxies as a function of the population age. We use deep Hubble Space Telescope/Advanced Camera for Surveys imaging of nearby dwarf galaxies in…
(Abridged) We present deep, sub-horizontal branch, multi-colour photometry of the Andromeda II dwarf spheroidal (And II dSph) taken with Subaru Suprime-Cam. We identify a red clump population in this galaxy, the first time this feature has…
We present the results of optical spectroscopy and imaging with the SAO 6m telescope for the dwarf galaxy DDO 68 (UGC 5340 = VV 542), falling into the region of very low density of luminous (L > L*) galaxies (Lynx-Cancer void). Its deep…
We have used UVES on VLT-UT2 to take spectra of 15 individual red giant stars in the centers of four nearby dwarf spheroidal galaxies: Sculptor, Fornax, Carina and Leo I. We measure the abundance variations of numerous elements in these low…
We present new, high sensitivity VLA observations of HI in four dwarf galaxies (UGCA 292, GR8, DDO 210, and DDO 216) and we use these data to study interactions between star formation and the interstellar medium. HI velocity dispersions and…
A near-infrared imaging study of the evolved stellar populations in the dwarf spheroidal galaxy Leo I is presented. Based on JHK observations obtained with the WFCAM wide-field array at the UKIRT telescope, we build a near-infrared…
The stellar population of the Pegasus dwarf irregular galaxy is investigated in images taken in the F439W (B), F555W (V), and F814W (I) bands with WFPC2. These and ground-based data are combined to produce color-magnitude diagrams which…