Related papers: Young Dwarf Galaxies and Cosmology
We study the correlation between the radio, mid-infrared and far-infrared properties for a sample of 28 blue compact dwarf (BCD) and low metallicity star-forming galaxies observed by Spitzer. We find that these sources extend the same…
We have investigated the radial g-r color gradients of early-type galaxies in the Sloan Digital Sky Survey (SDSS) DR6 in the redshift range 0.00<z<0.06. The majority of massive early-type galaxies show a negative color gradient (red-cored)…
We present the results of HI mapping with the NRAO VLA of one of the most metal-deficient blue compact dwarf (BCD) galaxies known, SBS 0335-052, with an oxygen abundance of only 1/40 that of the Sun. We study the structure and dynamics of…
The early chemical evolution of the Galaxy and the Universe is vital to our understanding of a host of astrophysical phenomena. Since the most metal-poor Galactic stars (with metallicities down to [Fe/H]\sim-5.5) are relics from the…
As part of the Dwarf galaxies Abundances and Radial-velocities Team (DART) program, we have measured the metallicities of a large sample of stars in four nearby dwarf spheroidal galaxies (dSph's): Sculptor, Sextans, Fornax, and Carina. The…
Candidates for the modest galaxies that formed most of the stars in the early universe, at redshifts $z > 7$, have been found in large numbers with extremely deep restframe-UV imaging. But it has proved difficult for existing spectrographs…
We have obtained near-infrared images and spectra of three blue compact dwarf galaxies of intermediate sub-solar metallicity Tol~35, Tol~3 and UM 462. This work is part of a larger project aimed to study the star formation and the stellar…
For a rotating galaxy, the inner circular-velocity gradient d_{R}V(0) provides a direct estimate of the central dynamical mass density, including gas, stars, and dark matter. We consider 60 low-mass galaxies with high-quality HI and/or…
In the local Universe, there is a handful of dwarf compact star-forming galaxies with extremely low oxygen abundances. It has been proposed that they are young, having formed a large fraction of their stellar mass during their last few…
The apparent lack of cold molecular gas in blue compact dwarf (BCD) galaxies is at variance with their intense star-formation episode. The CO molecule, often used a tracer of H2 through a conversion function, is selectively photodissociated…
Star-forming dwarf galaxies in the local Universe, especially extremely metal-poor ones, can be considered analogous to early galaxies of the Epoch of Reionization (z >= 6). Currently available telescopes cannot adequately detect and…
We present deep U, narrow-V, and I-band images of the ultracompact blue dwarf galaxy HS 0822+3542, obtained with the Advanced Camera for Surveys / High Resolution Channel of the Hubble Space Telescope. This object is extremely metal-poor…
Dwarf spheroidal (dSph) galaxies present an evolutionary puzzle that we explore in 40 early- and late-type dwarfs in the Local Group and nearby field. Although dSphs formed stars over extended periods, today all but one are free of…
In this paper we present some results concerning the effects of two instantaneous starbursts, separated by a quiescent period, on the dynamical and chemical evolution of blue compact dwarf galaxies. In particular, we compare the model…
We present near-infrared (NIR) spectroscopic observations in the wavelength range 0.90-2.40mum of eighteen low-metallicity blue compact dwarf (BCD) galaxies and six HII regions in spiral and interacting galaxies. Hydrogen and helium…
We examine the X-ray spectra of VII Zw 403, a nearby low-metallicity blue compact dwarf (BCD) galaxy. The galaxy has been observed to contain an X-ray source, likely a high mass X-ray binary (HMXB), with a luminosity of 1.3-23x10^38 erg…
We present high-quality ground-based spectroscopic observations of 54 supergiant H II regions in 50 low-metallicity blue compact galaxies with oxygen abundances 12 + log O/H between 7.1 and 8.3. We use the data to determine abundances for…
We review observational data about a sample of Local Volume objects containing about 1000 galaxies within 11 Mpc of the Milky Way. Dwarf galaxies with stellar masses $M_*/M_{\odot} < 9$ dex make up 5/6 of the sample. Almost 40% of them have…
The low metallicity interstellar medium of dwarf galaxies gives a different picture in the far infrared(FIR)/submillimetre(submm)wavelengths than the more metal-rich galaxies. Excess emission is often found in the submm beginning at or…
We present Giant Metrewave Radio Telescope (GMRT) observations for three (viz., DDO 68, SDSS J2104-0035 and UGC 772) of the six most metal-deficient actively star-forming galaxies known. Although there is a debate as to whether these…