scholarly journals The Radio Continuum of the Metal‐deficient Blue Compact Dwarf Galaxy SBS 0335−052

2004 ◽  
Vol 606 (2) ◽  
pp. 853-861 ◽  
Author(s):  
Leslie K. Hunt ◽  
Kristy K. Dyer ◽  
Trinh X. Thuan ◽  
James S. Ulvestad
Keyword(s):  
Dwarf Galaxy ◽  
Radio Continuum ◽  
Blue Compact Dwarf Galaxy

scholarly journals A multi-frequency study of the Wolf-Rayet blue compact dwarf galaxy He2-10

1999 ◽  
Vol 193 ◽  
pp. 610-611
Author(s):  
David I. Méndez ◽  
César Esteban ◽  
Miroslav D. Filipović ◽  
Matthias Ehle ◽  
Prank Haberl ◽  
...  
Keyword(s):  
High Resolution ◽  
Supernova Remnants ◽  
Dwarf Galaxy ◽  
Mechanical Action ◽  
Radio Continuum ◽  
High Resolution Spectroscopy ◽  
Continuum Emission ◽  
Star Forming ◽  
The Galaxy ◽  
Blue Compact Dwarf Galaxy

We present preliminary results on multi-wavelength observations of the Wolf-Rayet Blue Compact Dwarf Galaxy He2–10. These observations include Hα and continuum imaging, high-resolution Hα spectroscopy, high-resolution radio-continuum mapping at 6.3 and 3.5 cm and X-ray mapping. The deep Hα image reveals that the galaxy consists of a complex system of different star-forming knots surrounded by kpc-scale bubble-like and filamentary structures. The most interesting structure is a bipolar superbubble centered on the most intense star-formation knot. High-resolution spectroscopy of this structure indicates that it is expanding with a velocity in the range 75–250 km s−1. This kind of outflows is likely to be produced by the mechanical action of stellar winds and supernovae explosions in the intense starbursts that the galaxy hosts. This scenario is consistent with the finding of a very steep radio spectral index in the extended radio continuum emission (α = −0.59) that confirms the presence of a large number of supernova remnants in the galaxy.

scholarly journals Dust in the Extremely Metal‐Poor Blue Compact Dwarf Galaxy I Zw 18: TheSpitzerMid‐infrared View

2007 ◽  
Vol 662 (2) ◽  
pp. 952-958 ◽  
Author(s):  
Yanling Wu ◽  
V. Charmandaris ◽  
L. K. Hunt ◽  
J. Bernard‐Salas ◽  
B. R. Brandl ◽  
...  
Keyword(s):  
Dwarf Galaxy ◽  
Blue Compact Dwarf Galaxy

scholarly journals Discovery of the high-ionization emission line [Ne V] λ3426 in the blue compact dwarf galaxy Tol 1214–277

2004 ◽  
Vol 415 (2) ◽  
pp. L27-L30 ◽  
Author(s):  
Y. I. Izotov ◽  
K. G. Noeske ◽  
N. G. Guseva ◽  
P. Papaderos ◽  
T. X. Thuan ◽  
...  
Keyword(s):  
Emission Line ◽  
Dwarf Galaxy ◽  
High Ionization ◽  
Blue Compact Dwarf Galaxy

scholarly journals Determination of the OB Stellar Population of IZw18 on the Basis of its Hγ and Hδ Absorption lines

1999 ◽  
Vol 194 ◽  
pp. 444-447
Author(s):  
A. Sinanyan ◽  
D. Kunth ◽  
J. Lequeux ◽  
G. Comte ◽  
A. Petrosian
Keyword(s):  
Spectral Range ◽  
Stellar Population ◽  
Dwarf Galaxy ◽  
Absorption Lines ◽  
Spectroscopic Observations ◽  
Narrow Spectral Range ◽  
Blue Compact Dwarf Galaxy

On the basis of new spectroscopic observations of the blue compact dwarf galaxy IZw18 in the narrow spectral range between 4000Å and 4500Å absorption components of Hγ and Hδ lines were discovered. Equivalent widths of Hγ and Hδ lines have been measured. From available data the OB population of IZw18 was analyzed.

scholarly journals The Dark Blue Compact Dwarf Galaxy NGC 2915

1997 ◽  
Vol 14 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Gerhardt R. Meurer
Keyword(s):  
Dark Matter ◽  
Mass Distribution ◽  
Dwarf Galaxy ◽  
Dark Matter Halo ◽  
High Mass ◽  
Mass Star ◽  
Normal Galaxies ◽  
The Galaxy ◽  
Dark Blue ◽  
Blue Compact Dwarf Galaxy

AbstractRecent results on NGC 2915, the first blue compact dwarf galaxy to have its mass distribution modelled, are summarised. NGC 2915 is shown to have HI well beyond its detected optical extent. Its rotation curve is well determined and fit with maximum disk mass models. The dark matter halo dominates the mass distribution at nearly all radii, and has a very dense core compared to those of normal galaxies. High-mass star formation energises the HI in the centre of the galaxy, but appears to be maintained in viriai equilibrium with the dark matter halo. The implications of these results are briefly discussed.

Rotating Halos and Heavy Disks: the Case of NGC 2915

2004 ◽  
Vol 217 ◽  
pp. 172-173
Author(s):  
Frédéric S. Masset ◽  
Martin Bureau
Keyword(s):  
Surface Brightness ◽  
Spiral Structure ◽  
Dwarf Galaxy ◽  
Neutral Hydrogen ◽  
Dark Halo ◽  
Pattern Frequency ◽  
Spin Parameter ◽  
Low Surface Brightness ◽  
Hydrodynamical Simulations ◽  
Blue Compact Dwarf Galaxy

NGC 2915 is a blue compact dwarf galaxy embedded in an extended, low surface brightness HI disk with a bar and two-armed spiral structure. Common mechanisms are unable to explain those patterns and disk dark matter or a rotating triaxial dark halo were proposed as alternatives. Hydrodynamical simulations were run for each case and compared to observations using customized column density and kinematic constraints. The spiral structure can be accounted for by an unseen bar or triaxial halo, but the large bar mass or halo pattern frequency required make it unlikely that the spiral is driven by an external perturber. In particular, the spin parameter lambda is much higher than predicted by current CDM structure formation scenarios. Massive disk models show that when the gas surface density is scaled up by a factor of about 10, the disk develops a spiral structure matching the observed one in perturbed density as well as velocity. This suggests that the disk of NGC 2915 contains much more mass than is visible tightly linked to the neutral hydrogen. A classic (quasi-)spherical halo is nevertheless still required, as increasing the disk mass further to fit the circular velocity curve would make the disk violently unstable

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