Astrophysical: H II regions

  • Publication
    Comparison of the Hα Equivalent Width of H II Regions in a Flocculent and a Grand-Design Galaxy: Possible Evidence for Initial Mass Function Variations
    We present here a study of the Hα equivalent widths of the flocculent galaxy NGC 4395 and the grand-design galaxy NGC 5457. A difference between the mean values...
  • Publication
    Complex ionization structure and kinematics in the circumnuclear region of NGC 3227
    We present bidimensional spectroscopy of the circumnuclear region of the Seyfert galaxy NGC 3227. The physical and kinematical characteristics of the two...
  • Publication
    Density biases and temperature relations for DESIRED H II regions
    We present a first study based on the analysis of the DEep Spectra of Ionized REgions Data base (DESIRED). This is a compilation of 190 high signal-to-noise...
  • Publication
    Density Bounding in the H II Regions of Galactic Disks: Evidence and Consequences
    We present four lines of evidence leading to the conclusion that a notable fraction of the ionizing photon emission from the stars within H II regions in the...
  • Publication
    Density studies of giant extragalactic H II regions
    The variation of the electron density with position in a selected group of bright giant extragalactic H II regions has been studied using long slit...
  • Publication
    Density studies on giant extragalactic H II regions
    We report the results of a systematic study on the spatial variation of the electron density in a selected group of bright giant H II complexes in the galaxies...
  • Publication
    Density wave triggered star formation in grand design spirals
    In normal spiral galaxies the arms are the main sites for star formation. This is the cause of their optical contrast compared with the rest of the disc. The...
  • Publication
    Density waves and star formation in grand-design spirals
    Context. H II regions in the arms of spiral galaxies are indicators of recent star-forming processes. They may have been caused by the passage of the density...
  • Publication
    Detailed spectrophotometric study of the giant H II region NGC 604
    Detailed spectrophotometry in the visual and near-infrared is presented for four different slit positions over the core of NGC 604. The excitation ([O II]/[O...