Results 1 to 10 of about 176,382 (265)
Redshift, metallicity and size of two extended dwarf Irregular galaxies. A link between dwarf Irregulars and Ultra Diffuse Galaxies? [PDF]
Monthly Notices of the Royal Astronomical Society, 2017 We present the results of the spectroscopic and photometric follow-up of two field galaxies that were selected as possible stellar counterparts of local high velocity clouds. Our analysis shows that the two systems are distant (D>20 Mpc) dwarf irregular galaxies unrelated to the local HI clouds.
Michele Bellazzini +8 more
arxiv +9 more sources
The intrinsic shapes of dwarf irregular galaxies [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2013 We use the measured B band axial ratios of galaxies from an updated catalog of Local Volume galaxies to determine the intrinsic shape of dwarf irregular galaxies (de Vacouleurs' morphological types 8, 9 and 10). We find that the shapes change systematically with luminosity, with fainter galaxies being thicker.
Roychowdhury, Sambit +3 more
arxiv +7 more sources
Lopsidedness in dwarf irregular galaxies [PDF]
Monthly Notices of the Royal Astronomical Society, 2000 42 pages, LaTex.
Ana Heller +4 more
openalex +4 more sources
Giant Halos in Dwarf Irregular Galaxies vs. Dwarf Elliptical Galaxies [PDF]
Proceedings of the International Astronomical Union, 2005 We present a discovery of a giant stellar halo in NGC 6822, a dwarf irregular galaxy in the Local Group. This halo is mostly made of old red giants, showing striking features: 1) it is several times larger than the main body of the galaxy seen in the optical images, and 2) it is elongated in the direction almost perpendicular to the HI disk of NGC 6822.
Narae Hwang, Myung Gyoon Lee
arxiv +6 more sources
Oxygen abundances in dwarf irregular galaxies and the metallicity - luminosity relationship [PDF]
, 2001 The low-luminosity dwarf irregular galaxies are considered. The oxygen abundances in HII regions of dwarf irregular galaxies were recalculated from published spectra through the recently suggested P - method. It has been found that the metallicity of low-luminosity dwarf irregular galaxies, with a few exceptions, correlates well with galaxy luminosity.
L. S. Pilyugin
arxiv +3 more sources
The natural science underlying big history. [PDF]
ScientificWorldJournal, 2014 Nature’s many varied complex systems—including galaxies, stars, planets, life, and society—are islands of order within the increasingly disordered Universe. All organized systems are subject to physical, biological, or cultural evolution, which together comprise the grander interdisciplinary subject of cosmic evolution.
Chaisson EJ.
europepmc +2 more sources
Stellar Abundances in Dwarf Irregular Galaxies [PDF]
Carnegie Obs. Astrophy. Series, Vol. 4, Origin and Evolution of
the Elements, 2003, 2003 Dwarf irregular galaxies appear to have undergone very slow chemical evolution since they have low nebular abundances, but have had ongoing star formation over the past 15 Gyr. They are too distant for red giant abundance analyses to examine the details of their chemical evolution, however the isolated, bright blue supergiants do allow us to determine ...
Venn, K.A. +3 more
arxiv +4 more sources
DDO 43: A Prototypical Dwarf Irregular Galaxy? [PDF]
The Astronomical Journal, 2005 We present sensitive and high resolution 21 cm observations of the dwarf irregular (dIm) galaxy DDO 43, in conjunction with optical broad and narrow band images in U, B, V, and Halpha. The observations are used to examine the relationship between its HI morphology and kinematics to past and present star formation.
Caroline E. Simpson +2 more
openalex +5 more sources
Stellar Populations and the Star Formation Histories of LSB Galaxies—Part I: Optical and Hα Imaging
Advances in Astronomy, 2011 This paper presents optical and Hα imaging for a large sample of LSB galaxies selected from the PSS-II catalogs (Schombert et al., 1992).
James Schombert +2 more
doaj +2 more sources
Oxygen and Nitrogen in Isolated Dwarf Irregular Galaxies [PDF]
Astrophys.J.636:214-239,2005, 2005 We present long slit optical spectroscopy of 67 HII regions in 21 dwarf irregular galaxies to investigate the enrichment of oxygen, nitrogen, neon, sulfur, and argon in low mass galaxies. Oxygen abundances are obtained via direct detection of the temperature sensitive emission lines for 25 HII regions; for the remainder of the sample, oxygen abundances
Liese van Zee, Martha P. Haynes
arxiv +4 more sources