Related papers: Interstellar reddening correction using He I lines
In this paper we generalize the flux ratio method Bailey et al. (2009) to the case of two luminosity indicators and search the optimal luminosity-flux ratio relations on a set of spectra whose phases are around not only the date of bright…
We detail a technique for estimating the UV extinction and luminosity of UV selected galaxies using UV quantities alone. The technique is based on a tight correlation between the ratios of far infrared (FIR) to UV flux ratios and UV color…
We calculate the He I case B recombination cascade spectrum using improved radiative and collisional data. We present new emissivities over a range of electron temperatures and densities. The differences between our results and the current…
We present He-like line ratios (resonance, intercombination and forbidden lines) for totally and partially photoionized media. For solar plasmas, these line ratios are already widely used for density and temperature diagnostics of coronal…
We develop a prescription for estimating the interstellar medium oxygen abundances of distant star-forming galaxies using the ratio EWR_{23} formed from the equivalent widths of the [O II] 3727, [O III] 4959,5007 and Hbeta nebular emission…
Optical CCD spectra are used to determine the Fe abundances at several positions inside seven bright Galactic HII regions. The observed [FeIII] line ratios are compared with the predictions of different sets of collision strengths and…
We present spectroscopic observations of a sample of 72 emission-line objects, including mainly HII regions, in the spiral galaxy M 33. Spectra were obtained with the multi-object, wide field spectrograph AF2/WYFFOS at the 4.2m WHT…
We constrain the light extinction properties of Milky Way dust. We investigated the correlations between dust column density as inferred from infrared data and the observed colours of celestial objects at cosmological distances with low…
We present long-slit spectrophotometric observations in the red and near infrared of 12 HII galaxies. The spectral range includes the sulphur lines [SII] at wavelengths 6716, 6731 angstroms and [SIII] at 6312 angstroms and 9069, 9532…
We explore the relationship between dust-emission derived reddening \EBV\ and atomic hydrogen column density N(H I) derived from 21 cm emission surveys. We consider measurements at galactic latitude $|b| \ga 20$\degr\ and \EBV\ $\la$ 0.1…
We discuss the rest-frame optical emission line spectra of a large (~50) sample of z=3.1 Lyman alpha emitters (LAEs) whose physical properties suggest such sources are promising analogs of galaxies in the reionization era. Reliable Lyman…
We present the computation of effective refractive coefficients for inhomogeneous two-component grains with 3 kinds of inclusions with ${\rm m_{incl}=3.0+4.0i, 2.0+1.0i, 2.5+0.0001i}$ and a matrix with ${\rm m_m=1.33+0.01i}$ for 11 volume…
The measurement of the cosmological parameters from Type Ia supernovae hinges on our ability to compare nearby and distant supernovae accurately. Here we present an advance on a method for performing generalized K-corrections for Type Ia…
Emission line galaxies (ELGs), more generally star-forming galaxies, are valuable tracers of large-scale structure and therefore main targets of upcoming wide-area spectroscopic galaxy surveys. We propose a fixed-aperture shape estimator of…
A sample of SiO-masing late-type stars located in the inner Galaxy is analyzed with the goal of better constraining their obscuration. This reference sample allows us to define mathematical relations between their dereddened infrared…
We present very deep spectrophotometry of 14 bright extragalactic HII regions belonging to spiral, irregular, and blue compact galaxies. The data for 13 objects were taken with the HIRES echelle spectrograph on the Keck I telescope. We have…
We employed observational spectroscopic data of star-forming regions compiled from the literature and photoionization models to analyse the neon ionic abundances obtained using both optical and mid-infrared emission-lines. Comparing Ne++/H+…
Currently, the primordial helium abundance is best estimated through spectroscopic observations of H II regions in metal-poor galaxies. However these determinations are limited by several systematic uncertainties which ultimately limit our…
HII regions are the ionized spheres surrounding high-mass stars. They are ideal targets for tracing Galactic structure because they are predominantly found in spiral arms and have high luminosities at infrared and radio wavelengths. In the…
The slopes of interstellar reddening lines in the 2MASS J-H versus H-Ks diagrams for 26 areas in the inner Galaxy (from Vulpecula to Centaurus) are determined. For this aim we use the red-clump giants located inside and behind spiral arms,…