Star Formation and the Interstellar Medium in Four Dwarf Irregular Galaxies
نویسندگان
چکیده
منابع مشابه
Dwarf Irregular Galaxies and the Intergalactic Medium
Dwarf galaxies (DGs) are more numerous than large galaxies. Most dwarfs in clusters are dEs, but in the field they belong mostly to late types. The importance of late-type DGs in the context of the intergalactic medium (IGM) lies in the fact that (at least some) are probably " young " galaxies forming stars for the first time. Many DGs have significant amounts of interstellar gas, they may form...
متن کاملThe Impact of Star Formation on the Interstellar Medium in Dwarf Galaxies: II. The Formation of Galactic Winds
Images and longslit, echelle spectra of the Hα emission from 14 dwarf galaxies and M82 have been used to identify expanding shells of ionized gas. Supershells (radius > 300 pc) are found in 12 of the dwarfs. The measured shell sizes and expansion speeds constrain the ages and power requirements of the bubbles. The dynamical age of the larger bubbles is typically about 10 Myr, and ionized shells...
متن کاملStar Formation in Sculptor Group Dwarf Irregular Galaxies and the Nature of “Transition” Galaxies
We present new Hα narrow band imaging of the HII regions in eight Sculptor Group dwarf irregular (dI) galaxies. The Hα luminosities of the detected HII regions range from some of the faintest detected in extragalactic HII regions (∼ 10 erg s in SC 24) to some of the most luminous (∼ 10 erg s in NGC 625). The total Hα luminosities are converted into current star formation rates (SFR). Comparing ...
متن کاملStar Formation in Dwarf Galaxies
We explore mechanisms for the regulation of star formation in dwarf galaxies. We concentrate primarily on a sample in the Virgo cluster, which has HI and blue total photometry, for which we collected Hα data at the Wise Observatory. We find that dwarf galaxies do not show the tight correlation of the surface brightness of Hα (a star formation indicator) with the HI surface density, or with the ...
متن کاملInterstellar Medium Oxygen Abundances of Dwarf Irregular Galaxies in Centaurus A and Nearby Groups⋆
We present results of optical spectroscopy of 35 H II regions from eight dwarf galaxies in the Centaurus A group. [O III] λ4363 is detected in ESO272−G025 and ESO324−G024, and direct oxygen abundances of 12+log(O/H) = 7.76 ± 0.09 and 7.94±0.11 are derived, respectively. For the remaining galaxies, abundances are derived using common bright-line methods. To compare the influence of group environ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2003
ISSN: 0004-637X,1538-4357
DOI: 10.1086/375581