| Autor: |
Andreas Rieschick, Gerhard Hensler, Simone Recchi, Joachim Köppen |
| Rok vydání: |
2005 |
| Předmět: |
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| Zdroj: |
Highlights of Astronomy. 13:554-559 |
| ISSN: |
1539-2996 |
| DOI: |
10.1017/s1539299600016579 |
| Popis: |
Investigations 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 dlrrs with old underlying stellar populations have passed the regime of observed N/O-0 values within almost 2 Gyrs after their formation even with gas loss by means of supernova-driven galactic winds. Therefore alternative processes like gas infall must be invoked. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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