Integral field spectroscopy of supernova explosion sites: constraining
  mass and metallicity of the progenitors - I. Type Ib and Ic supernovae
  Integral field spectroscopy of 11 type-Ib/c supernova explosion sites in
nearby galaxies has been obtained using UH88/SNIFS and Gemini-N/GMOS. The use
of integral field spectroscopy enables us to obtain both spatial and spectral
information of the explosion site, allowing the identification of the parent
stellar population of the supernova progenitor star. The spectrum of the parent
population provides metallicity determination via strong-line method and age
estimation obtained via comparison with simple stellar population (SSP) models.
We adopt this information as the metallicity and age of the supernova
progenitor, under the assumption that it was coeval with the parent stellar
population. The age of the star corresponds to its lifetime, which in turn
gives the estimate of its initial mass. With this method we were able to
determine both the metallicity and initial (ZAMS) mass of the progenitor stars
of the type Ib and Ic supernovae. We found that on average SN Ic explosion
sites are more metal-rich and younger than SN Ib sites. The initial mass of the
progenitors derived from parent stellar population age suggests that SN Ic have
more massive progenitors than SN Ib. In addition, we also found indication that
some of our SN progenitors are less massive than ~25 Msun, indicating that they
may have been stars in a close binary system that have lost their outer
envelope via binary interactions to produce Ib/c supernovae, instead of single
Wolf-Rayet stars. These findings support the current suggestions that both
binary and single progenitor channels are in effect in producing type Ib/c
supernovae. This work also demonstrates the power of integral field
spectroscopy in investigating supernova environments and active star forming
regions.
