Related papers: Episodic starbursts in dwarf spheroidal galaxies: …
We present a calculation of protostellar disk formation and evolution in which gaseous clumps (essentially, the first Larson cores formed via disk fragmentation) are ejected from the disk during the early stage of evolution. This is a…
Using a high resolution N-body simulation of a two-component dwarf galaxy orbiting in the potential of the Milky Way, we study two effects that lead to significant biases in mass estimates of dwarf spheroidal galaxies. Both are due to the…
40 galaxies are currently known as, or suspected to be Local Group members within a radius of 1.8 Mpc. 37 of these galaxies are dwarf galaxies with M_B > -18.5 mag. I present a compilation of the star formation histories of dwarf…
We describe the optical properties of a sample of 101 gas-rich field dwarf galaxies found on PSS-II (Second Palomar Sky Survey) plates, most newly discovered as part of a survey to investigate the clustering properties of dwarf galaxies…
We use a series of N-body/smoothed particle hydrodynamics simulations and analytic arguments to show that the presence of an effective temperature floor in the interstellar medium at T_F ~ 10^4 K naturally explains the tendency for low-mass…
We use data for faint (M_B > -14.5) dwarf irregular galaxies drawn from the FIGGS survey to study the correlation between the atomic gas density (Sigma_gas,atomic) and star formation rate (Sigma_SFR) in the galaxies. The estimated gas phase…
The duration of a starburst is a fundamental parameter affecting the evolution of galaxies yet, to date, observational constraints on the durations of starbursts are not well established. Here we study the recent star formation histories…
Using star formation histories derived from optically resolved stellar populations in nineteen nearby starburst dwarf galaxies observed with the Hubble Space Telescope, we measure the stellar mass surface densities of stars newly formed in…
In the widely adopted LambdaCDM scenario for galaxy formation, dwarf galaxies are the building blocks of larger galaxies. Since they formed at relatively early epochs when the background density was relatively high, they are expected to…
(Abridged) We use N-body simulations to study the evolution of dwarf spheroidal galaxies (dSphs) driven by galactic tides. We adopt a cosmologically-motivated model where dSphs are approximated by a King model embedded within an NFW halo.…
A number of mechanisms have been proposed to connect star-forming dwarf irregular galaxies with the formation of non-star-forming dwarf spheroidal galaxies, but distinguishing between these mechanisms has been difficult. We use the Via…
Cosmic-ray energy densities in central regions of starburst galaxies, as inferred from radio and gamma-ray measurements of, respectively, non-thermal synchrotron and neutral pion decay emission, are typically U_p = O(100)eV/cm3, i.e.…
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 have studied the stellar population and internal structure of the core of the Ursa Minor dwarf spheroidal galaxy, using a sample of stars selected to be members based on their proper motions. In agreement with previous studies, we find…
Star formation in galaxies is triggered by a combination of processes, including gravitational instabilities, spiral wave shocks, stellar compression, and turbulence compression. Some of these persist in the far outer regions where the…
Strong bursts of star formation in galaxies may be triggered either by internal or external mechanisms. We study the distribution and kinematics of the HI gas in the outer regions of 18 nearby starburst dwarf galaxies, that have accurate…
We present a comparison of semi-analytic models of the phase-space structure of tidal debris with observations of stars associated with the Sagittarius dwarf galaxy (Sgr). We find that many features in the data can be explained by these…
(abridged)Integrated star formation rate (SFR) and specific star formation rate (sSFR), derived from the spectroscopic data obtained by SDSS DR4 are used to show that the star formation activity in galaxies (M_r<=-20.5) found on the…
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 explore whether Local Group dwarf spheroidal (dSph) galaxies might have hosted Earth-like planets dwelling unexposed for several billions of years to major galactic threats to life, such as supernovae and gamma-ray bursts. To this aim,…