arXiv subjects

Roger Coziol

Publications and source records attributed to Roger Coziol.

20 records · Page 2Linked to original sources

arXiv1996

The Role of Starburst in the Chemical Evolution of Galaxies

In a diagram of metallicity (z) vs. luminosity (M$_B$), the different types of nearby (Z $< 0.05$) starburst galaxies seem to follow the same linear relationship as the normal spiral and irregular galaxies. However, for comparable luminosities the more massive starburst nucleus galaxies (SBNGs) show a slight metallic defficiency as compared to the giant spiral galaxies. Furthermore, the SBNGs do not seem to follow the same relationship between z and Hubble type (T) than the normal galaxies. The early-type SBNGs are metal poor as compared to normal galaxies. It may suggests that the chemical evolution of a majority of the nearby starbursts galaxies is not completely over and that the present burst represent an important phase of this process.

astro-ph↗

arXiv1995

The history of star formation of starburst galaxies

In this paper, we use different luminosity ratios to trace the histories of star formation of two different kinds of starburst galaxies: HII galaxies and starburst nucleus galaxies (SBNGs). The mean star formation rates (SFRs) for these galaxies is comparable, and compatible with a near constant star formation over a few Gyr period. We have also found an interesting difference between the burst stellar population of the SBNGs and the HII galaxies: SBNGs have an excess of intermediate-mass stars as compared to HII galaxies. We interpreted this difference as a sign that SBNGs have experienced a higher frequency of bursts of star formation than the HII galaxies. This interpretation is qualitatively consistent with the Stochastic Self Propagation of Star Formation (SSPSF) theory, which suggests that the starburst phenomenon depends on internal processes, regulated by the evolution of massive stars.

astro-ph↗