The spectral investigation of seven HII regions in Kazarian galaxies

TL;DR

This study spectroscopically analyzes seven HII regions in Kazarian galaxies, determining element abundances, star formation rates, and ages, revealing their chemical properties and evolutionary status.

Contribution

It provides the first detailed spectrophotometric analysis of HII regions in Kazarian galaxies, including element abundances and star formation characteristics.

Findings

Oxygen abundance ranges from 7.94 to 8.35.

Star formation rates are comparable to those in spiral and irregular galaxies.

HII regions are likely older than 100-300 Myr, with nitrogen enrichment evidence.

Abstract

According to SDSS DR5 spectra the spectrophotometric investigations of seven HII regions of six Kazarian galaxies are conducted. The abundances of heavy elements and helium and also quantity of ionizing stars and star formation rate are determined. The oxygen abundance 12+log(O/H) lies in the range 7.94 - 8.35. The mean log(S/O), log(Ar/O) and log(Ne/O) abundance ratios are equal to: -1.63, -2.37 and -0.78, respectively. The log(N/O) abundance ratio of investigated HII regions is in the interval -0.63 to -1.37. They occupy the same area in the diagram N/O - O/H as the high-excitation HII regions. Most likely, the ages of investigated HII regions are larger than 100-300 Myr, required for the enrichment in nitrogen by intermediate-mass stars. The star formation rate is one order as in HII regions in spiral and irregular galaxies, and is in the interval 0.05 - 0.81 M year-1.