Spectroscopic study of the HII regions in the NGC 1232 galaxy
  NGC 1232 is a face-on spiral galaxy that serves as an excellent laboratory
for the study of star formation due to its proximity. Recent studies have
revealed interesting features about this galaxy: X-ray observations suggest
that it recently collided with a dwarf galaxy, however, no apparent remnant is
observed. Here we search for evidence of this collision. We used long-slit
optical spectra in two different positions obtained with the Goodman
spectrograph at the SOAR telescope. We detected 18 HII regions in the
north-south direction and 22 HII regions in the east-west direction and a
background galaxy, NGC 1232B, for which we present the first redshift
measurement and spectral analysis. We used the stellar population fitting
technique to study the underlying stellar population and to subtract it from
the spectra to measure the emission lines. The emission lines were used to
determine the extinction, electron density, chemical abundance, and the
star-formation rate gradient of NGC 1232. As is common in spiral galaxies, we
found a stellar population gradient with older populations at the central
regions and younger ones towards the outskirts, along with a negative oxygen
abundance gradient of -0.16 dex/re. Due to the difficulty of measuring
important emission lines, the number of objects for the abundance gradient is
small, but there is a hint that this galaxy has a broken gradient profile, with
a drop towards the center. If the collision caused any disturbance in the
galaxy, we believe it would be small and hard to detect with a limited number
of objects. From all the other measurements, we found no deviations from a
typical spiral galaxy and no significant difference between different
directions in the galaxy. The stellar population and emission line analysis of
NGC 1232B suggest that it is a starburst galaxy.
