English
Related papers

Related papers: Stellar associations powering HII regions $\unicod…

200 papers

We have conducted a search for ionized gas at 3.6 cm, using the Very Large Array, towards 31 Galactic intermediate- and high-mass clumps detected in previous millimeter continuum observations. In the 10 observed fields, 35 HII regions are…

Observing giant HII regions at fine spatial scales uncovers detailed structures and reveals variations in ionization, abundance, and dynamical properties of ionized gas and the effect of stellar feedback. Using emission line data of M33…

Based on the ISO spectral catalogue of compact HII regions by Peeters et al. (2001), we present a first analysis of the hydrogen recombination and atomic fine-structure lines originated in the ionized gas. The sample consists of 34 HII…

Results of a study of physical parameters of stellar population in star formation regions in galaxies with signs of peculiarity NGC 3963 and NGC 7292 are presented. The study was carried out based on the analysis of photometric (UBVRI…

Astrophysics of Galaxies · Physics 2024-10-10 A. S. Gusev , F. Kh. Sakhibov , A. V. Moiseev , V. S. Kostiuk , D. V. Oparin

We present a new model of the optical nebular emission from HII regions by combin- ing the results of the Binary Population and Spectral Synthesis (bpass) code with the photoion- ization code cloudy (Ferland et al. 1998). We explore a…

Astrophysics of Galaxies · Physics 2017-11-15 Lin Xiao , J. J. Eldridge , Elizabeth Stanway , L. Galbany

A growing number of indicators are now being used with some confidence to measure the metallicity(Z) of photoionisation regions in planetary nebulae, galactic HII regions(GHIIRs), extra-galactic HII regions(EGHIIRs) and HII galaxies(HIIGs).…

Astrophysics · Physics 2012-05-10 Michael Taylor , Angeles I. Diaz

We study the stellar population of galaxies with active star formation, determining ages of the stellar components by means of spectral population synthesis of their absorption spectra. The data consist of optical spectra of 185 nearby ($z…

Astrophysics · Physics 2009-10-31 D. Raimann , E. Bica , T. Storchi-Bergmann , J. Melnick , H. Schmitt

We examine the gas and stellar metallicities in a sample of HII galaxies from the Sloan Digital Sky Survey, which possibly contains the largest homogeneous sample of HII galaxy spectra to date. We eliminated all spectra with an insufficient…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Pieter Westera , François Cuisinier , Didier Curty , Roland Buser

We present constraints on the massive star and ionized gas properties for a sample of 62 star-forming galaxies at $z\sim2.3$. Using BPASS stellar population models, we fit the rest-UV spectra of galaxies in our sample to estimate age and…

Disc galaxies exhibit radial metallicity gradients in both their stellar and gaseous components. The star-forming gas (SFG) in HII regions and young stars (YSs) trace the recent evolutionary history of the galaxy. We aim to assess the…

Astrophysics of Galaxies · Physics 2026-03-23 Isha Shailesh , Patricia B. Tissera , Emanuel Sillero

(Abridged) We reassess the alpha-element abundance ratios (Ne/O, S/O, Ar/O) with respect to metallicity in ~1000 spectra of Galactic and extragalactic HII regions and star-forming galaxies (SFGs) of the local Universe. Using the DEep…

A number of very small isolated HII regions have been discovered at projected distances up to 30 kpc from their nearest galaxy. These HII regions appear as tiny emission line objects in narrow band images obtained by the NOAO Survey for…

We present results from a photometric H-alpha survey of 22 nuclear rings, aiming to provide insight into their star formation properties, including age distribution, dynamical timescales, star formation rates, and galactic bar influence. We…

Astrophysics · Physics 2009-11-13 Lisa M. Mazzuca , Johan H. Knapen , Sylvain Veilleux , Michael W. Regan

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…

Astrophysics of Galaxies · Physics 2009-01-21 G. F. Hagele , A. I. Diaz , E. Terlevich , E. Perez-Montero , R. Terlevich , M. V. Cardaci

We have discovered a number of very small isolated HII regions 20-30 kpc from their nearest galaxy. The HII regions appear as tiny emission line dots (ELdots) in narrow band images obtained by the NOAO Survey for Ionization in Neutral Gas…

Astrophysics · Physics 2007-05-23 E. V. Ryan-Weber , M. E. Putman , K. C. Freeman , G. R. Meurer , R. L. Webster

Using Green Bank Telescope radio recombination line (RRL) data, we analyze the role of leaking radiation from HII regions in maintaining the ionization of the interstellar medium. We observed a sample of eight Galactic HII regions of…

Astrophysics of Galaxies · Physics 2019-02-27 Matteo Luisi , L. D. Anderson , Bin Liu , D. Anish Roshi , Ed Churchwell

Extensive photoionization model grids for single star HII regions using a variety of recent state-of-the-art stellar atmosphere models have been computed with the main aim of constraining/testing their predicted ionizing spectra against…

Astrophysics · Physics 2009-11-10 C. Morisset , D. Schaerer , J. -C. Bouret , F. Martins

Aims. In this paper we study the influence of the ionizing cluster mass on the emission line spectrum of Hii regions in order to determine the influence of low mass clusters on the integrated emission line spectra of galaxies. Methods. For…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-18 Marcos Villaverde , Miguel Cervino , Valentina Luridiana

Integral field units enable resolved studies of a large number of star-forming regions across entire nearby galaxies, providing insight on the conversion of gas into stars and the feedback from the emerging stellar populations over…