Bibcode
Cairós, L. M.; Caon, N.; García-Lorenzo, B.; Kelz, A.; Roth, M.; Papaderos, P.; Streicher, O.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 547, id.A24 15pp.
Fecha de publicación:
11
2012
Revista
Número de citas
20
Número de citas referidas
19
Descripción
Context. Blue compact galaxies (BCG) are narrow emission-line systems
that undergo a violent burst of star formation. They are compact,
low-luminosity galaxies, with blue colors and low chemical abundances,
which offer us a unique opportunity to investigate collective star
formation and its effects on galaxy evolution in a relatively simple,
dynamically unperturbed environment. Spatially resolved
spectrophotometric studies of BCGs are essential for a better
understanding of the role of starburst-driven feedback processes on the
kinematical and chemical evolution of low-mass galaxies near and far.
Aims: We carry out an integral field spectroscopy (IFS) study of
a sample of luminous BCGs, with the aim to probe the morphology,
kinematics, dust extinction, and excitation mechanisms of their warm
interstellar medium (ISM). Methods: We obtained IFS data for five
luminous BCGs with VIRUS-P, the prototype instrument for the Visible
Integral Field Replicable Unit Spectrograph, attached to the 2.7 m
Harlan J. Smith Telescope at the McDonald Observatory. VIRUS-P consists
of a square array of 247 optical fibers, which covers a 109″
× 109″ field of view, with a spatial sampling of 4farcs2 and
a 0.3 filling factor. We observed in the 3550-5850 Å spectral
range, with a resolution of 5 Å FWHM. From these data we built
two-dimensional maps of the continuum and the most prominent
emission-lines ([O ii] λ3727, Hγ, Hβ and [O iii]
λ5007), and investigated the morphology of diagnostic
emission-line ratios and the extinction patterns in the ISM as well as
stellar and gas kinematics. Additionally, from integrated spectra we
inferred total line fluxes and luminosity-weighted extinction
coefficients and gas-phase metallicities. Results: All galaxies
exhibit an overall regular morphology in the stellar continuum, while
their warm ISM morphology is more complex: in II Zw 33 and Mrk 314, the
star-forming regions are aligned along a chain-structure; Haro 1, NGC
4670 and III Zw 102 display several salient features, such as extended
gaseous filaments and bubbles. A significant intrinsic absorption by
dust is present in all galaxies, the most extreme case being III Zw 102.
Our data reveal a plethora of kinematical patterns, from overall regular
gas and stellar rotation to complex velocity fields produced by
structurally and kinematically distinct components.