Volume 390, Number 1, July IV 2002
|Page(s)||59 - 64|
|Section||Cosmology (including clusters of galaxies)|
|Published online||05 July 2002|
New abundance measurements in UKS 1927–177, a very metal-poor galaxy in the Local Group*
European Southern Observatory, Casilla 19001, Santiago 19, Chile
2 Osservatorio Astronomico di Padova, vicolo dell'Osservatorio 5, 35122 Padova, Italy e-mail: (rizzi, held)@pd.astro.it
3 Dipartimento di Astronomia, Università di Padova, vicolo dell'Osservatorio 2, 35122 Padova, Italy e-mail: email@example.com
4 Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 e-mail: firstname.lastname@example.org
Corresponding author: I. Saviane, email@example.com
Accepted: 15 May 2002
We present new results from optical spectroscopy of the brightest Hii region in the dwarf irregular galaxy in Sagittarius (SagDIG). From high signal-to-noise spectra, reddening-corrected line flux ratios have been measured with typical uncertainties of a few percent, from which the oxygen abundance is rediscussed, and new abundance estimates are derived for N and Ne. The O abundance in SagDIG, estimated with the empirical abundance indicator and other methods, is in the range to . The fact that SagDIG is 10 times closer than I Zw 18 makes it an ideal target to test the hypothesis of the existence of young galaxies in the present-day universe. Indeed, stellar photometry suggests that this galaxy may harbor a stellar population older than a few Gyr, and possibly an old stellar component as well. The case of SagDIG therefore supports the view that very low chemical abundances can be maintained throughout the life of a dwarf stellar system, even in the presence of multiple star formation episodes.
Key words: galaxies: individual: SagDIG / galaxies: abundances / galaxies: dwarf / galaxies: ISM / galaxies: irregular / Local Group
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.