Related papers: Leo P: How Many Metals can a Very Low-Mass, Isolat…

We present KPNO 4-m and LBT/MODS spectroscopic observations of an HII region in the nearby dwarf irregular galaxy Leo P discovered recently in the Arecibo ALFALFA survey. In both observations, we are able to accurately measure the…

Leo P is a low-luminosity dwarf galaxy discovered through the blind HI Arecibo Legacy Fast ALFA (ALFALFA) survey. The HI and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with active star formation, an…

Leo P is a low-luminosity dwarf galaxy discovered through the blind HI Arecibo Legacy Fast ALFA (ALFALFA) survey. The HI and follow-up optical observations have shown that Leo P is a gas-rich dwarf galaxy with both active star formation and…

We present new HI spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our HI images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The HI…

We present the first stellar spectroscopy in the low-luminosity (M_V ~-9.3 mag), dwarf galaxy Leo P. Its significantly low oxygen abundance (3% solar) and relative proximity (~1.6 Mpc) make it a unique galaxy to investigate the properties…

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…

Isolated, low-mass galaxies provide the opportunity to assess the impact of reionization on their star formation histories (SFHs) without the ambiguity of environmental processes associated with massive host galaxies. There are very few…

Leo T is the lowest mass galaxy known to contain neutral gas and to show signs of recent star formation, which makes it a valuable laboratory for studying the nature of gas and star formation at the limits of where galaxies are found to…

The James Webb Space Telescope (JWST) has revealed unexpectedly rapid galaxy assembly in the early universe, in tension with models of star and galaxy formation. In the gas conditions typical of early galaxies, particularly their low…

We predict the mass fraction of oxygen lost from galaxies in a cosmological simulation as a function of stellar mass and environment at the present day. The distribution with stellar mass is bimodal, separating star-forming and quenched…

Study the ionized gas in metal-poor environments is key to understanding the mechanisms regulating galaxy evolution. However, most of the previous studies of extragalactic HII regions rely on unresolved observations of gaseous structures.…

Extremely metal-poor (XMP) galaxies are systems with gas-phase oxygen abundances below $\sim$5% Solar metallicity (12+log(O/H)$\le$7.35). These galaxies populate the metal-poor end of the mass-metallicity and luminosity-metallicity…

Extremely metal-poor (XMP) galaxies are low-mass, star-forming galaxies with gas-phase oxygen abundances below 12+log(O/H) = 7.35 (~1/20 Zsun). Galaxy evolution scenarios suggest three pathways to form an XMP: (1) secular evolution at low…

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 elemental abundances for multiple HII regions in Leo A and GR 8 obtained from long slit optical spectroscopy of these two nearby low luminosity dwarf irregular galaxies. As expected from their luminosities, and in agreement with…

The damped Lyman alpha systems seen in the spectra of high redshift QSOs offer the means to determine element abundances in galaxies observed while still at an early stage of evolution. Such measurements, which have only recently come…

We have obtained spectra of 102 red giant branch (RGB) stars in the Leo I dwarf spheroidal galaxy (dSph) and 74 RGB stars in the Leo II dSph using LRIS on the Keck I 10-meter Telescope. We report on the calcium abundances [Ca/H] derived…

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.…

We present a high spectral resolution survey of the most metal-poor damped Lyman-alpha absorption systems (DLAs) aimed at probing the nature and nucleosynthesis of the earliest generations of stars. Our survey comprises 22 systems with iron…

We use previously-published moderate-resolution spectra in combination with stellar atmosphere models to derive the first measured chemical abundance ratios in the Leo II dSph galaxy. We find that for spectra with SNR > 24, we are able to…