Results 61 to 70 of about 12,147 (249)

The Interstellar Medium in Dwarf Irregular Galaxies

Annual Review of Astronomy and Astrophysics
Dwarf irregular (dIrr) galaxies are among the most common type of galaxy in the Universe. They typically have gas-rich, low-surface-brightness, metal-poor, and relatively thick disks. Here, we summarize the current state of our knowledge of the interstellar medium (ISM), including atomic, molecular, and ionized gas, along with their dust properties and
Hunter, Deidre A., Elmegreen, Bruce G., Madden, Suzanne C.   +2 more
openaire   +3 more sources

The Early Chemical Evolution of Dwarf Irregular Galaxies [PDF]

Highlights of Astronomy, 2005
AbstractInvestigations have been performed to understand the age of dwarf irregular galaxies from the point of view of their presently low chemical abundances and the enhanced star-formation rate. While for a few objects, like e.g. I Zw 18, their assumed relative youth can be verified by models taking a double-starburst behavior into account, those ...
Andreas Rieschick, Joachim Köppen, Simone Recchi, Gerhard Hensler   +3 more
openaire   +3 more sources

Chemical and Photometric Evolution Models for Disk, Irregular, and Low Mass Galaxies

Advances in Astronomy, Volume 2014, Issue 1, 2014., 2014
We summarize the updated set of multiphase chemical evolution models performed with 44 theoretical radial mass initial distributions and 10 possible values of efficiencies to form molecular clouds and stars. We present the results about the infall rate histories, the formation of the disk, and the evolution of the radial distributions of diffuse and ...
Mercedes Mollá, Jorge Iglesias Páramo
wiley   +1 more source

A Comprehensive Archival Search for Counterparts to Ultra-Compact High Velocity Clouds: Five Local Volume Dwarf Galaxies [PDF]

, 2015
We report five Local Volume dwarf galaxies (two of which are presented here for the first time) uncovered during a comprehensive archival search for optical counterparts to ultra-compact high velocity clouds (UCHVCs).
Bennet, P., Caldwell, N., Crnojević, D., Guhathakurta, P., Hargis, J., James, B. L., Koposov, S., McLeod, B., Morrell, N., Olszewski, E., Peacock, M., Salinas, R., Sand, D. J., Seth, A. C., Simon, J. D., Stark, D. P., Strader, J., Tollerud, E. J., Toloba, E., Willman, B.   +19 more
core   +2 more sources

First Stellar Abundances in the Dwarf Irregular Galaxy Sextans A [PDF]

The Astronomical Journal, 2004
We present the abundance analyses of three isolated A-type supergiant stars in the dwarf irregular galaxy Sextans A from high-resolution spectra the UVES spectrograph at the VLT. Detailed model atmosphere analyses have been used to determine the stellar atmospheric parameters and the elemental abundances of the stars.
Christophe Pinte, Eline Tolstoy, Rolf-Peter Kudritzki, Andreas Kaufer, Kim A. Venn   +4 more
openaire   +4 more sources

100 Proof: H i Observations of 100 Nearby Dwarf Galaxies with the 100 m Green Bank Telescope

The Astronomical Journal
We describe the results of observations with the 100 m Robert C. Byrd Green Bank Telescope in the H i line of 105 nearby dwarf galaxies, 60 of which were discovered recently in the DESI Legacy Imaging Surveys.
Aleksandra E. Nazarova, John M. Cannon, Igor D. Karachentsev, Dmitry I. Makarov, Maksim I. Chazov, Lila Schisgal, William St. John   +6 more
doaj   +1 more source

Witnessing a Transformation to Blue-cored Dwarf Early-type Galaxies in Filaments and the Cluster Outskirts: Gas-phase Abundances and Internal Kinematics Perspectives

The Astrophysical Journal, 2023
The presence of transitional dwarf galaxies in filaments and cluster outskirts may be closely related to preprocessing in the filament; however, the underlying mechanism is not yet comprehensively understood.
Jiwon Chung, Joon Hyeop Lee, Hyunjin Jeong, Suk Kim   +3 more
doaj   +1 more source

Oxygen and Nitrogen in Isolated Dwarf Irregular Galaxies

The Astrophysical Journal, 2006
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
openaire   +3 more sources

Leaf Anatomy and Photochemical Behaviour of Solanum lycopersicum L. Plants from Seeds Irradiated with Low‐LET Ionising Radiation

The Scientific World Journal, Volume 2014, Issue 1, 2014., 2014
Plants can be exposed to ionising radiation not only in Space but also on Earth, due to specific technological applications or after nuclear disasters. The response of plants to ionising radiation depends on radiation quality/quantity and/or plant characteristics. In this paper, we analyse some growth traits, leaf anatomy, and ecophysiological features
V. De Micco, R. Paradiso, G. Aronne, S. De Pascale, M. Quarto, C. Arena, Charles Hocart   +6 more
wiley   +1 more source

FIGGS: Faint Irregular Galaxies GMRT Survey

, 2007
The Faint Irregular Galaxies GMRT Survey (FIGGS) is a large program aimed at providing a comprehensive and statistically robust characterisation of the neutral ISM properties of faint (M_B > -14.5), nearby, gas rich, dwarf irregular galaxies using the ...
Begum, Ayesha, Chengalur, Jayaram N., Kaisin, S. S., Karachentsev, I. D., Sharina, Margarita   +4 more
core   +1 more source