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Related papers: Interstellar reddening correction using He I lines

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We have introduced a new method of estimating the electron temperature and density of H II regions by using single dish observations. In this method, multiple hydrogen radio recombination lines of different bands are computed under the…

Solar and Stellar Astrophysics · Physics 2019-11-14 F. -Y. Zhu , Q. -F. Zhu , J. -Z. Wang , J. -S Zhang

This work presents a Bayesian algorithm to fit the recombination and collisionally excited line spectra of gas photoionized by clusters of young stars. The current model consists in fourteen dimensions: two electron temperatures, one…

Astrophysics of Galaxies · Physics 2019-06-05 Vital Fernández , Elena Terlevich , Angeles I. Díaz , Roberto Terlevich

We present a new technique based on multi-band near ultraviolet and optical photometry to measure both the stellar intrinsic properties, ie luminosity and effective temperature, and the interstellar dust extinction along the line of sight…

Astrophysics · Physics 2009-11-07 Martino Romaniello , Nino Panagia , Salvatore Scuderi , Robert P. Kirshner

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…

We use a large sample of galaxies at z~3 to establish a relationship between reddening, neutral gas covering fraction (fcov(HI)), and the escape of ionizing photons at high redshift. Our sample includes 933 galaxies at z~3, 121 of which…

Astrophysics of Galaxies · Physics 2016-09-21 Naveen A. Reddy , Charles C. Steidel , Max Pettini , Milan Bogosavljevic , Alice Shapley

We present new quantitative classification methods for emission-line galaxies, which are specially designed to be used in deep galaxy redshift surveys. A good segregation between starbursts and active galactic nuclei, i.e. Seyferts 2s and…

Astrophysics · Physics 2015-06-24 Claudia S. Rola , Elena Terlevich , Roberto J. Terlevich

The determination of the heavy element abundances from giant extragalactic H II regions is based on collisionally excited lines. We argue that in the presence of temperature variations the abundances determined are lower limits to the real…

Astrophysics · Physics 2007-05-23 Manuel Peimbert , Antonio Peimbert

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 consider the deconvolution of the thermal and the turbulent profiles for a pair of ions with different atomic weights under the condition that the lines are formed in an absorbing medium with fluctuating density and velocity fields. Our…

Astrophysics · Physics 2007-05-23 Sergei A. Levshakov , Wilhelm W. Kegel

In an attempt to remove the systematic errors which have plagued the calibration of the HII region abundance sequence, we have theoretically modeled the extragalactic HII region sequence. We then used the theoretical spectra so generated in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Angel R. Lopez-Sanchez , M. A. Dopita , L. J. Kewley , H. J. Zahid , D. C. Nicholls , J. Scharwachter

This paper continues our study of the behaviour of near infrared helium recombination lines in planetary nebula. We find that the 1.7007um 4^3D-3^3P HeI line is a good measure of the HeI recombination rate, since it varies smoothly with the…

Astrophysics · Physics 2009-11-07 S. L. Lumsden , P. J. Puxley , M. G. Hoare

We have observed a large sample of compact planetary nebulae in the near-infrared to determine how the 2^1P-2^1S HeI line at 2.058um varies as a function of stellar effective temperature, Teff. The ratio of this line with HI Br g at 2.166um…

Astrophysics · Physics 2009-10-31 S. L. Lumsden , P. J. Puxley , M. G. Hoare

We present VLT/SINFONI near-infrared (NIR) integral field spectroscopy of six $z \sim 0.2$ Lyman break galaxy "analogs" (LBAs), from which we detect HI, HeI, and [FeII] recombination lines, and multiple H$_2$ ro-vibrational lines in…

Astrophysics of Galaxies · Physics 2019-12-30 John F. Wu , Andrew J. Baker , Timothy M. Heckman , Erin K. S. Hicks , Dieter Lutz , Linda J. Tacconi

We present a systematic study of the intensity mapping technique using updated models for the different emission lines from galaxies and identify which ones are more promising for cosmological studies of the post reionization epoch. We…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-25 José Fonseca , Marta B. Silva , Mário G. Santos , Asantha Cooray

Based on O II recombination lines we present a new calibration (called O II[RL]) of Pagel's O23 indicator to determine the O/H abundance ratio in extragalactic H II regions and emission line galaxies. The O II(RL) calibration produces O/H…

We present results of deep echelle spectrophotometry of eight Galactic HII regions located at Galactocentric distances between 6.3 and 10.4 kpc. The data have been taken with the Very Large Telescope (VLT) Ultraviolet Echelle Spectrograph…

Astrophysics · Physics 2009-11-10 C. Esteban , J. Garcia-Rojas , M. Peimbert , A. Peimbert , M. T. Ruiz , M. Rodriguez , L. Carigi

We use a spectroscopic sample of 286 star-forming galaxies (SFGs) at 1<z<3 from the GMASS survey to study different star formation rate (SFR) estimators. Infrared (IR) data are used to derive empirical calibrations to correct ultraviolet…

Astrophysics of Galaxies · Physics 2015-10-14 M. Talia , A. Cimatti , L. Pozzetti , G. Rodighiero , C. Gruppioni , F. Pozzi , E. Daddi , C. Maraston , M. Mignoli , J. Kurk

We present high S/N measurements of the H I Ly alpha absorption line toward 16 Galactic targets which are at distances between approximately 190 and 2200 pc, all beyond the wall of the Local Bubble. We describe the models used to remove…

Astrophysics of Galaxies · Physics 2023-04-05 S. D. Friedman , P. Chayer , E. B. Jenkins , T. M. Tripp , G. M. Williger , G. Hebrard , P. Sonnentrucker

The Kepler Input Catalog (KIC) provides reddening estimates for its stars, based on the assumption of a simple exponential dusty screen. This project focuses on evaluating and improving these reddening estimates for the KIC's giant stars,…

Solar and Stellar Astrophysics · Physics 2015-06-22 Gail Zasowski , Deokkeun An , Marc Pinsonneault