scholarly journals Multiwavelength Observations of the Low-Metallicity Blue Compact Dwarf Galaxy SBS 0335−052

2001 ◽  
Vol 122 (4) ◽  
pp. 1736-1746 ◽  
Author(s):  
Daniel A. Dale ◽  
George Helou ◽  
Gerry Neugebauer ◽  
B. T. Soifer ◽  
David T. Frayer ◽  
...  
Keyword(s):  
Dwarf Galaxy ◽  
Low Metallicity ◽  
Blue Compact Dwarf Galaxy ◽  
Multiwavelength Observations

scholarly journals Haro15: Is it actually a low metallicity galaxy?

2009 ◽  
Vol 5 (S265) ◽  
pp. 243-244
Author(s):  
Verónica Firpo ◽  
Guillermo Bosch ◽  
Guillermo Hägele ◽  
Ángeles I. Díaz ◽  
Nidia Morrell
Keyword(s):  
Dwarf Galaxy ◽  
Empirical Methods ◽  
Chemical Abundances ◽  
Physical Conditions ◽  
Ionization Structure ◽  
The Galaxy ◽  
Low Metallicity ◽  
Echelle Spectroscopy ◽  
Abundance Determination ◽  
Blue Compact Dwarf Galaxy

AbstractWe present a detailed study of the physical properties of the nebular material in multiple knots of the blue compact dwarf galaxy Haro 15. Using long slit and echelle spectroscopy, obtained at Las Campanas Observatory, we study the physical conditions (electron density and temperature), ionic and total chemical abundances of several atoms, reddening and ionization structure. The latter was derived by comparing the oxygen and sulphur ionic ratios to their corresponding observed emission line ratios (the η and η' plots) in different regions of the galaxy. Applying direct and empirical methods for abundance determination, we perform a comparative analysis between these regions.

scholarly journals VLT/FORS Surveys of Wolf-Rayet Stars in the Nearby Universe

2007 ◽  
Vol 3 (S250) ◽  
pp. 327-332
Author(s):  
Lucy J. Hadfield ◽  
Paul A. Crowther
Keyword(s):  
Local Group ◽  
Narrow Band ◽  
Dwarf Galaxy ◽  
Narrow Band Imaging ◽  
Interstellar Extinction ◽  
Spectroscopic Studies ◽  
Order Of Magnitude ◽  
Low Metallicity ◽  
Massive Clusters ◽  
Blue Compact Dwarf Galaxy

AbstractWe present results from a series of VLT/FORS narrow-band imaging and spectroscopic surveys of Wolf-Rayet (WR) stars in nearby spiral galaxies and compare observed populations in high- and low metallicity environments. The metal-rich galaxy M 83 is seen to host an exceptional WR content, with over 1000 WR stars being detected. N(WC)/N(WN) ~ 1.2 and late-type WC subtypes dominate the WC population. At low metallicity, ~100 stars has been identified within NGC 1313, with N(WC)/N(WN) ~ 0.5. In contrast to M83, the WC population of NGC 1313 comprises solely early subtypes plus a WO star (the first WO star to be identified beyond the Local Group). Consequently, the dominant WC subtype may serve as a crude metallicity diagnostic for WR galaxies.In addition, the WR content of the blue compact dwarf galaxy NGC 3125 is examined. Previous UV and optical spectroscopic studies of knot A in NGC 3125 derive WR populations which differ by more than an order of magnitude. New VLT observations and archival HST spectroscopy reconcile this discrepancy via the use of LMC WR spectral templates and a reduced nebular-derived interstellar extinction. Empirical N(WR)/N(O) ratios for clusters within NGC 3125 are a factor of two higher than evolutionary synthesis predictions but are consistent with those observed for other young massive clusters.

scholarly journals [TSUP]12[/TSUP]CO Mapping of the Low-Metallicity Blue Compact Dwarf Galaxy Markarian 86

2002 ◽  
Vol 573 (2) ◽  
pp. L101-L105 ◽  
Author(s):  
A. Gil de Paz ◽  
S. A. Silich ◽  
B. F. Madore ◽  
C. Sánchez Contreras ◽  
J. Zamorano ◽  
...  
Keyword(s):  
Dwarf Galaxy ◽  
Low Metallicity ◽  
Blue Compact Dwarf Galaxy

scholarly journals Role of massive stars in the evolution of primitive galaxies

2012 ◽  
Vol 10 (H16) ◽  
pp. 370-370
Author(s):  
Sara Heap
Keyword(s):  
Galaxy Evolution ◽  
Dwarf Galaxy ◽  
Massive Stars ◽  
Stellar Winds ◽  
Stellar Feedback ◽  
Low Metallicity ◽  
Low Mass ◽  
Blue Compact Dwarf Galaxy

AbstractAn important factor controlling galaxy evolution is feedback from massive stars. It is believed that the nature and intensity of stellar feedback changes as a function of galaxy mass and metallicity. At low mass and metallicity, feedback from massive stars is mainly in the form of photoionizing radiation. At higher mass and metallicity, it is in stellar winds. I Zw 18 is a local blue, compact dwarf galaxy that meets the requirements for a primitive galaxy: low halo mass <109M⊙, strong photoionizing radiation, no galactic outflow, and very low metallicity, log(O/H)+12=7.2. We will describe the properties of massive stars and their role in the evolution of I Zw 18, based on analysis of ultraviolet images and spectra obtained with HST.

scholarly journals Deep spectroscopy of the low-metallicity blue compact dwarf galaxy SBS 0335-052

2001 ◽  
Vol 378 (2) ◽  
pp. L45-L48 ◽  
Author(s):  
Y. I. Izotov ◽  
F. H. Chaffee ◽  
D. Schaerer
Keyword(s):  
Dwarf Galaxy ◽  
Low Metallicity ◽  
Blue Compact Dwarf Galaxy

scholarly journals The evolutionary status of the low-metallicity blue compact dwarf galaxy SBS 0940+544

2001 ◽  
Vol 378 (3) ◽  
pp. 756-776 ◽  
Author(s):  
N. G. Guseva ◽  
Y. I. Izotov ◽  
P. Papaderos ◽  
F. H. Chaffee ◽  
C. B. Foltz ◽  
...  
Keyword(s):  
Dwarf Galaxy ◽  
Evolutionary Status ◽  
Low Metallicity ◽  
Blue Compact Dwarf Galaxy
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