相关论文: Star clusters and young populations in the dwarf i…
Leo A is an isolated gas-rich dwarf irregular galaxy of low stellar mass and metallicity residing at the outskirts of the Local Group. Ages of the stellar populations in Leo A range from $\sim$10 Myr to $\sim$10 Gyr. So far, only one star…
We analysed a population of bright-red (BR) stars in the dwarf irregular galaxy Leo A by using multicolour photometry data obtained with the Subaru/Suprime-Cam ($B$, $V$, $R$, $I$, $H\alpha$) and HST/ACS ($F475W$ & $F814W$) instruments. In…
We have surveyed a complete extent of Leo A - an apparently isolated gas-rich low-mass dwarf irregular galaxy in the Local Group. The $B$, $V$, and $I$ passband CCD images (typical seeing $\sim$0.8") were obtained with Subaru Telescope…
We present a new method to derive 2D star formation histories in dwarf irregular galaxies. Based on multicolor stellar photometry data we have found that in the Leo A galaxy during the last $\sim$400 Myr star formation was propagating…
We have studied Leo A - the isolated and extremely gas rich dwarf irregular galaxy of very low stellar mass and metallicity. Ages of the stellar populations in Leo A are ranging from ~10 Myr to ~10 Gyr. Here we report the discovery of an…
We present deep Hubble Space Telescope single-star photometry of Leo A in B, V, and I. Our new field of view is offset from the centrally located field observed by Tolstoy et al. (1998) in order to expose the halo population of this galaxy.…
As part of a major program to use isolated Local Group dwarf galaxies as near-field probes of cosmology, we have obtained deep images of the dwarf irregular galaxy Leo A with the Advanced Camera for Surveys aboard the Hubble Space…
The unprecedented detail of the WFPC2 colour-magnitude diagrams of the resolved stellar population of Leo A presented here allows us to determine a new distance and an accurate star formation history for this extremely metal-poor Local…
We report the discovery of a significant old population in the dwarf spheroidal (dSph) galaxy Leo I as a result of a wide-area search with the ESO New Technology Telescope. Studies of the stellar content of Local Group dwarf galaxies have…
We characterize massive stars (M>8 M_sun) in the nearby (D~0.8 Mpc) extremely metal-poor (Z~5% Z_sun) galaxy Leo A using Hubble Space Telescope ultra-violet (UV), optical, and near-infrared (NIR) imaging along with Keck/LRIS and…
We present results from ground-based optical imaging of a low-mass dwarf galaxy discovered by the ALFALFA 21-cm HI survey. Broadband (BVR) data obtained with the WIYN 3.5-m telescope at Kitt Peak National Observatory (KPNO) are used to…
We present deep HST F555W (V) and F814W (I) observations of a central field in the Local Group dwarf spheroidal (dSph) galaxy Leo I. The resulting color-magnitude diagram (CMD) reaches I \simeq 26 and reveals the oldest ~10-15 Gyr old…
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 carry out sensitive searches for the CO J=1-0 and J=2-1 lines in the giant extragalactic HI ring in Leo to investigate the star formation process within environments where gas metallicities are close to solar but physical conditions are…
Dwarf galaxies in the local group provide a unique astrophysical laboratory. Despite their proximity some of these systems still lack a reliable distance determination as well as studies of their stellar content and star formation history.…
In this Letter, we announce the discovery of a new dwarf galaxy, Leo T, in the Local Group. It was found as a stellar overdensity in the Sloan Digital Sky Survey Data Release 5 (SDSS DR5). The color-magnitude diagram of Leo T shows two…
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…
Leo I is considered one of the youngest dwarf spheroidals (dSph) in the Local Group. Its isolation, extended star formation history (SFH), and recent perigalacticon passage (~1 Gyr ago) make Leo~I one of the most interesting nearby stellar…
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…
We study the relationship between the field star formation and cluster formation properties in a large sample of nearby dwarf galaxies. We use optical data from the Hubble Space Telescope and from ground-based telescopes to derive the ages…