Related papers: HI and star formation in the most metal-deficient …
Interacting galaxies surrounded by HI tidal debris are ideal sites for the study of young clusters and tidal galaxy formation. The process that triggers star formation in the low-density environments outside galaxies is still an open…
The goal of this study is to measure parameters of the integrated HI emission for twenty-two dwarf galaxies with oxygen abundance 12+log(O/H) in the range of 7.42 to 7.65, which are representatives of the eXtremely Metal-Deficient (XMD)…
The study of ionized gas morphology and kinematics in nine eXtremely Metal-Deficient (XMD) galaxies with the scanning Fabry-Perot interferometer on the SAO 6-m telescope is presented. Some of these very rare objects (with currently known…
We present HI spectral-line imaging of the extremely metal-poor galaxy DDO 68. This system has a nebular oxygen abundance of only 3% Z$_{\odot}$, making it one of the most metal-deficient galaxies known in the local volume. Surprisingly,…
The GMRT observations of the HI 21~cm-line emission from 13~nearby dwarf star-forming galaxies are presented. The ranges of star formation rates and stellar masses of the sample galaxies are 0.03 -- 1.7~$M_\odot~{\rm yr}^{-1}$ and 0.04 --…
(abridged) We present 8.2m VLT spectroscopic observations of 28 HII regions in 16 emission-line galaxies and 3.6m ESO telescope spectroscopic observations of 38 HII regions in 28 emission-line galaxies. These emission-line galaxies were…
DDO 68 is the second most metal-poor star-forming galaxy (12+log(O/H)=7.14). Its peculiar optical morphology and the data on its HI distribution and kinematics indicate the merger origin. We use the photometry of the SDSS u,g,r,i images of…
We present new, high sensitivity VLA observations of HI in four dwarf galaxies (UGCA 292, GR8, DDO 210, and DDO 216) and we use these data to study interactions between star formation and the interstellar medium. HI velocity dispersions and…
We present Giant Metrewave Radio Telescope (GMRT), HI 21cm observations of SBS 0335-052E and SBS 0335-052W, a close pair of dwarf galaxies, which are further unusual in being the most metal-poor star-forming galaxies known. We present…
We present the star formation history of the extremely metal-poor dwarf galaxy DDO 68, based on our photometry with the Advanced Camera for Surveys. With a metallicity of only $12+\log(O/H)=7.15$ and a very isolated location, DDO 68 is one…
There are only a few ``dark galaxy'' candidates discovered to date in the local Universe. One of the most prominent of them is the SW component of a merging system HI 1225+01. On the other hand, the number of known very metal-poor gas-rich…
We present GMRT HI observations of an eXtremely Metal Deficient (XMD) galaxy SBS 1129+576 (12 + log(O/H) = 7.41). Our HI observations show that the galaxy is strongly interacting with a companion galaxy, SBS 1129+577. A third, smaller…
We have obtained new HI observations with the 100m Green Bank Telescope (GBT) for a sample of 29 extremely metal-deficient star-forming Blue Compact Dwarf (BCD) galaxies, selected from the Sloan Digital Sky Survey spectral data base to be…
Recent observations have discovered a number of extremely gas-rich very faint dwarf galaxies possibly embedded in low-mass dark matter halos. We investigate star formation histories of these gas-rich dwarf ("almost dark") galaxies both for…
Abridged. Low-metallicity star-forming dwarf galaxies are prime targets to understand the chemical enrichment of the interstellar medium. The HI region provides important constraints on the dispersal and mixing of heavy elements released by…
In recent years a wealth of data and detailed hydrodynamical simulations have appeared that show the effects of interactions between the ICM and galaxies. Single dish observations show that cluster galaxies are deficient in their HI content…
New HI observations are presented for a complete sample of 109 low luminosity star-forming galaxies taken from the KPNO International Spectroscopic Survey (KISS), the first CCD-based wide-field objective-prism survey for emission-line…
We present a study of the stellar populations of a sample of 39 local, field early-type galaxies whose HI properties are known from interferometric data. Our aim is to understand whether stellar age and chemical composition depend on the HI…
We present the analysis of a survey of atomic and molecular gas in interacting and merging galaxies (Horellou & Booth 1997). The sample is optically selected and contains all interacting galaxies (~ 60 systems) in a well-defined region of…
The first galaxies contain stars born out of gas with little or no metals. The lack of metals is expected to inhibit efficient gas cooling and star formation but this effect has yet to be observed in galaxies with oxygen abundance relative…