Results 231 to 240 of about 12,408 (264)

Abundances in dwarf irregular galaxies

Publications of the Astronomical Society of the Pacific, 1986
The results of abundance studies of dwarf irregular galaxies and similar objects are reviewed with special attention to variations in the CNO element group. Observations of the forbidden N II and semiforbidden C III lines in the most metal-poor galaxy known, IZw 18, are presented for the first time and CNO abundances are derived via a photoionization ...
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Dwarf Irregular Galaxies

2004
Dwarf irregular galaxies at optical wavelengths are small, faint and appear to be unstructured and irregular in shape. They are typically gas-rich, metal-poor systems, with varying levels of STAR FORMATION occurring in a haphazard manner across the ...
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Giant Outflows from Irregular Dwarf Galaxies

AIP Conference Proceedings, 2005
High‐resolution long‐slit echelle spectroscopy of the two irregular dwarf galaxies NGC 2366 and NGC 4861 was performed with the 4 m telescope of the Kitt Peak National Observatory to examine the structure and the kinematics of the ionized gas. Additionally, we use Hα images from the 3.5 m telescope of the Calar Alto Observatory (NGC 2366) and from the ...
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Kinematic lopsidedness in the dwarf irregular galaxy WLM

Proceedings of the International Astronomical Union, 2023
Abstract To investigate whether an m = 1 perturbation in the halo potential could be a mechanism creating observed kinematical asymmetry in the rotation curve of the dwarf irregular galaxy WLM, we fit a theoretical rotational velocity associated with such a perturbation in ...
M. Khademi, Y. Yang, F. Hammer, S. Nasiri   +3 more
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Blue Compact Dwarfs: Extreme Dwarf Irregular Galaxies

1987
In Hubble’s classification scheme, dwarf irregular galaxies (dIs) are low luminosity systems (MB≳ -16) which are at the end of the galaxy morphological sequence and which lack both a dominating nucleus and rotational symmetry [1]. We concentrate here on a class of dIs which are so extreme in these properties that they appear almost stellar in ...
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Stochastic Star Formation in Dwarf Irregular Galaxies

1984
The observational properties (fractionary mass of gas, metallicity and colours) of a sample of dwarf irregular and magellanic type galaxies are discussed in the light of the stochastic self propagating star formation model of Gerola et al. (1980). To this aim, one-zone model galaxies are presented which take into account both the bursting mode of star ...
C. Chiosi, F. Matteucci
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Dwarf Irregular Galaxies of the Local Group

2014
Local Group dwarf irregulars (dIrrs) cover an enormous range in star formation properties. Here I discuss these tiny galaxies as probes of star formation at the extremes of low gas densities and low metallicities. We have learned that (1) Star formation is inefficient in dIrrs and yet at very low \(\Sigma_{\rm HI}\) (\(
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Local Group Census: The Dwarf Irregular Galaxy NGC6822

2006
In the framework of the Local Group Census (LGC), an imaging pro- gramme to search for emission line objects in the Local Group, we present the detec- tion of 13 new candidate planetary nebulae (PNe) and follow-up optical spectroscopic confirmation in the dwarf irregular galaxy NGC 6822.
P. Leisy, L. Magrini, R.L.M. Corradi, A. Mampaso   +3 more
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A population of red candidate massive galaxies ~600 Myr after the Big Bang

Nature, 2023
Ivo Labbe, Pieter van Dokkum, Erica Nelson   +2 more
exaly  

Simulations of the formation, evolution and clustering of galaxies and quasars

Nature, 2005
Volker Springel, Simon D M White, Adrian Jenkins   +2 more
exaly