TY - JOUR
T1 - Bidimensional spectroscopy of NGC 4214
T2 - Evolutionary state and interstellar extinction
AU - Maíz-Apellániz, J.
AU - Mas-Hesse, J. M.
AU - Muñoz-Tuñón, C.
AU - Vílchez, J. M.
AU - Castañeda, H. O.
PY - 1998/1/20
Y1 - 1998/1/20
N2 - We have mapped spectrophotometrically the star-forming regions in the center of the nearby SBm galaxy NGC 4214 with the aim of analyzing the spatial distribution of some of its physical properties (density, excitation, emission line intensity, extinction) and their relationship with the distribution and evolutionary state of the stellar population. Star formation takes place mainly in two big complexes, although several smaller star-forming regions spread over the central bar of the galaxy have also been identified. The comparison of different observable parameters (W(Hβ), Wolf-Rayet population, effective temperature, UV absorption lines) with the predictions of synthesis models provides a consistent picture in which the different star formation episodes took all place around 3 Myr ago, with a very narrow spread in time (in any case within 1 Myr). The brightest star forming complex, located at the visible nucleus of the galaxy, is apparently the most evolved one. The surrounding interstellar medium is being disrupted, with a clear spatial decoupling between stars, gas and dust clouds. The dust appears concentrated at the boundaries of the ionized region, affecting mainly the nebular emission lines, while the stellar continuum itself is located in a region relatively free of dust and gas. This decoupling may explain the differences in extinction found previously between the stellar continuum and the emission lines. On the other hand, the ionized gas is essentially co-spatial with the massive stellar clusters in the SE complex, which apparently is less evolved. Nevertheless, the dust tends to be concentrated in isolated clouds located generally at the boundaries of the line emitting nebulae. We postulate that stellar winds have contributed to concentrate these dust particles in the inter-cluster medium.
AB - We have mapped spectrophotometrically the star-forming regions in the center of the nearby SBm galaxy NGC 4214 with the aim of analyzing the spatial distribution of some of its physical properties (density, excitation, emission line intensity, extinction) and their relationship with the distribution and evolutionary state of the stellar population. Star formation takes place mainly in two big complexes, although several smaller star-forming regions spread over the central bar of the galaxy have also been identified. The comparison of different observable parameters (W(Hβ), Wolf-Rayet population, effective temperature, UV absorption lines) with the predictions of synthesis models provides a consistent picture in which the different star formation episodes took all place around 3 Myr ago, with a very narrow spread in time (in any case within 1 Myr). The brightest star forming complex, located at the visible nucleus of the galaxy, is apparently the most evolved one. The surrounding interstellar medium is being disrupted, with a clear spatial decoupling between stars, gas and dust clouds. The dust appears concentrated at the boundaries of the ionized region, affecting mainly the nebular emission lines, while the stellar continuum itself is located in a region relatively free of dust and gas. This decoupling may explain the differences in extinction found previously between the stellar continuum and the emission lines. On the other hand, the ionized gas is essentially co-spatial with the massive stellar clusters in the SE complex, which apparently is less evolved. Nevertheless, the dust tends to be concentrated in isolated clouds located generally at the boundaries of the line emitting nebulae. We postulate that stellar winds have contributed to concentrate these dust particles in the inter-cluster medium.
KW - Galaxies: ISM
KW - Galaxies: individual NGC 4214
KW - Galaxies: irregular
KW - Galaxies: starburst
UR - http://www.scopus.com/inward/record.url?scp=0040977190&partnerID=8YFLogxK
M3 - Artículo
SN - 0004-6361
VL - 329
SP - 409
EP - 430
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
IS - 2
ER -