Bibcode
Maíz-Apellániz, J.; Muñoz-Tuñón, C.; Tenorio-Tagle, G.; Mas-Hesse, J. M.
Referencia bibliográfica
Astronomy and Astrophysics, v.343, p.64-80 (1999)
Fecha de publicación:
3
1999
Revista
Número de citas
30
Número de citas referidas
28
Descripción
We present in this paper a detailed study of the kinematical properties
of the ionized gas around the young massive star clusters in the nucleus
of NGC 4214. The analysis is based on bidimensional spectroscopical
data, allowing to derive the spatial variation of different properties
(intensity, velocity and width / line splitting) of the emission lines
Hα and [O iii] lambda 5007 along the nuclear region. We have found
that the Giant H ii region around the two most massive clusters in NGC
4214 (A and B) is resolved into two clearly separated regions. We have
not detected superbubbles with the properties we would expect according
to the evolutionary state of the stellar clusters, but just a partial
ring feature around the most massive one and two expanding shells around
cluster B. The first expanding shell seems to have experienced blowout,
whereas the second one is still complete. A possible explanation to this
phenomenon is that the most massive stars in a starburst spend a large
fraction of their lives buried inside their original molecular clouds.
Champagne flows might have formed at the borders of the regions,
especially on the SE complex, explaining the existence of the diffuse
ionized gas around the galaxy. As a consequence of these results we
postulate that NGC 4214 is indeed a dwarf spiral galaxy, with a thin ( ~
200 pc) disk that inhibits the formation of large scale structures in
the ISM. The mechanical input deposited by the star formation complexes,
in a variety of physical processes that include the free expanding
bubbles liberated after blowout and photoevaporation of the parent
clouds, have succeeded in generating the structures now detected far
from the disk, giving place to the large-scale structure which now
enriches the optical appearance of the galaxy.