相关论文: The emission line sequence of H II galaxies

Using a sample of unprecedented size (about 400 objects) of H II galaxies in which the oxygen abundances have been obtained using the temperature derived from the [OIII] 4363/5007 line ratio, we confirm that the H II galaxies form a very…

We constructed diagnostic diagrams using emission line ratios and equivalent widths observed in several samples of HII galaxies. The diagrams are compared to predictions from new photoionization models for evolving starbursts. We find that…

Using cosmological simulations to make useful, scientifically relevant emission line predictions is a relatively new and rapidly evolving field. However, nebular emission lines have been particularly challenging to model because they are…

We have studied the viability of new theoretical models which combine a chemical evolution code, an evolutionary synthesis code and a photoionization code, to understand the star formation and evolution of H{\sc ii} galaxies. The emission…

We have computed a series of realistic and self-consistent models of the emitted spectra of H{\sc ii} galaxies. Our models combine different codes of chemical evolution, evolutionary population synthesis and photoionization. The emitted…

We present a self-consistent model under a star-bursting scenario for H{\sc ii} galaxies, combining different codes of chemical evolution, evolutionary population synthesis and photoionization. The results obtained reproduce simultaneoulsy…

We investigate the ionization mechanisms for hidden broad-line region (HBLR) and non-HBLR Seyfert 2 galaxies by comparing some optical emission line ratios. We note that the [N II]6583/H_alpha ratio of the non-HBLR Seyfert 2 galaxies is…

In this work we investigate the evolution of the X-ray emission of a cluster of single young massive stars with different metallicities. We have considered the X-ray contribution originated by the diffuse gas heated by the mechanical energy…

Medium-resolution spectra from 3650 angstroms to 10,000 angstroms are presented for 96 giant H II regions distributed in 20 spiral galaxies. We have calculated two separate grids of photoionization models, adopting single-star atmospheres…

Understanding the ionizing spectrum of low-metallicity galaxies is of great importance for modeling and interpreting emission line observations of early/distant galaxies. Although a wide suite of stellar evolution, atmosphere, population…

We analyze the stellar and nebular energy distributions of starbursts using our evolutionary synthesis model PEGASE coupled to the photoionization code CLOUDY. The originality of this study is to relate the evolution and the metallicity of…

We study the kinematics and excitation mechanisms of H2 and [Fe II] lines in a sample of 67 emission-line galaxies with Infrared Telescope Facility SpeX near-infrared (NIR, 0.8-2.4 micrometers) spectroscopy together with new photoionisation…

We report the oxygen abundances of the HII regions of a sample of low surface brightness (LSB) galaxies. We provide analytic functions describing the McGaugh (1991) calibration of the R_23 method. We use this and the equivalent width (EW)…

We propose a methodology to perform a self-consistent analysis of the physical properties of the emitting gas of HII galaxies adequate to the data that can be obtained with the XXI century technology. This methodology requires the…

Chemical abundances provide important clues to the evolution of galaxies. Ionized nebulae are one of the main sources of chemical abundance measurements, especially in external galaxies. Studies of H II regions have shown that the overall…

Metal abundance and its evolution are studied for Mg II quasar absorption line systems from their weak, unsaturated spectral lines using stacked spectra from the archived data of Sloan Digital Sky Survey. They show an abundance pattern that…

The origin of nebular HeII emission, which is frequently observed in low-metallicity (O/H) star-forming galaxies, remains largely an unsolved question. Using the observed anticorrelation of the integrated X-ray luminosity per unit of star…

(Abridged) We use high S/N spectra of 20 HII regions in the giant spiral galaxy M101 to derive electron temperatures for the HII regions and robust metal abundances over radii R = 0.19-1.25 Ro (6-41 kpc). We compare the consistency of…

HII regions, ionized nebulae where massive star formation has taken place, exhibit a wealth of emission lines that are the fundamental basis for estimating the chemical composition of the Universe. For more than 80 years, a discrepancy of…

We present a self-consistent study of the stellar populations and the ionized gas in a sample of 10 HII galaxies with, at least, four measured electron temperatures and a precise determination of ionic abundances following the "direct…