Related papers: A new method to derive star formation histories 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$0.8") were obtained with Subaru Telescope…
Despite recent success in forming realistic present-day galaxies, simulations still form the bulk of their stars earlier than observations indicate. We investigate the process of stellar mass assembly in low-mass field galaxies, a dwarf and…
Stellar feedback in dwarf galaxies plays a critical role in regulating star formation via galaxy-scale winds. Recent hydrodynamical zoom simulations of dwarf galaxies predict that the periodic outward flow of gas can change the…
The results of UBV and H alpha imaging of a large sample of isolated dwarf irregular galaxies are interpreted in the context of composite stellar population models. The observed optical colors are best fit by composite stellar populations…
Though smooth, extended spheroidal stellar outskirts have long been observed around nearby dwarf galaxies, it is unclear whether dwarfs generically host an extended stellar halo. We use imaging from the Hyper Suprime-Cam Subaru Strategic…
We have fit the far-ultraviolet (FUV) to mid-infrared (MIR) spectral energy distributions (SEDs) for several nearby galaxies ($<$ 20 Mpc). Global, radial, and local photometric measurements are explored to better understand how SED-derived…
The combination of huge databases of galaxy spectra and advances in evolutionary synthesis models in the past few years has renewed interest in an old question: How to estimate the star formation history of a galaxy out of its integrated…
We measure the first stellar velocity dispersion of the Leo A dwarf galaxy, \sigma = 9.3 +- 1.3 km/s. We derive the velocity dispersion from the radial velocities of ten young B supergiants and two HII regions in the central region of Leo…
We study a sample of 5 dwarf irregular galaxies in the CenA/M83 group, which are companions to the giant elliptical CenA. We aim at deriving their physical properties over their lifetime and compare them to those of dwarfs located in…
Low-mass dwarf galaxies are very sensitive test-beds for theories of cosmic structure formation since their weak gravitational fields allow the effects of the relevant physical processes to clearly stand out. Up to now, no unified account…
Using N-body simulations we study the evolution of separate stellar populations in dwarf galaxies in the context of the tidal stirring scenario for the formation of dwarf spheroidal (dSph) galaxies in the Local Group. The dwarf galaxies,…
With the state-of-the-art Gaia astrometry, the number of confirmed white dwarfs has reached a few hundred thousand. We have reached the era where small features in the white dwarf luminosity function (WDLF) of the solar neighbourhood can be…
We compare the metallicity distribution of Galactic Halo stars with 3D realizations of hierarchical galaxy formation. Outflows from dwarf galaxies enrich the intergalactic medium inhomogeneously, at a rate depending on the local galaxy…
An unresolved question in galaxy evolution is whether the star formation histories of low mass systems are preferentially dominated by starbursts or modes that are more quiescent and continuous. Here, we quantify the prevalence of global…
We perform a deep wide-field imaging survey of nearby galaxies using H$\alpha$ and broadband filters to investigate the characteristics of star formation in galaxies. Motivated by the finding that star formation rates (SFRs) derived from…
We report on new measurements of the luminosity function (LF) and mass function (MF) of field low-mass dwarfs derived from Sloan Digital Sky Survey (SDSS) Data Release 6 (DR6) photometry. The analysis incorporates ~15 million low-mass stars…
We present sensitive and high resolution 21 cm observations of the dwarf irregular (dIm) galaxy DDO 43, in conjunction with optical broad and narrow band images in U, B, V, and Halpha. The observations are used to examine the relationship…
The Hubble Deep Field (HDF) is the deepest set of multicolor optical photometric observations ever undertaken, and offers a valuable data set with which to study galaxy evolution. Combining the optical WFPC2 data with ground-based…
We develop a method for interpreting faint galaxy data which focuses on the integrated light radiated from the galaxy population as a whole. The emission history of the universe at ultraviolet, optical, and near-infrared wavelengths is…
We present Halpha narrow-band imaging of 17 dwarf irregular galaxies (dIs) in the nearby Centaurus A Group. Although all large galaxies of the group have a current or recent enhanced star formation episode, the dIs have normal star…