Add to ORKGThe theoretical calculations of helium triplet line strengths, including collisional enhancement, are compared to astronomical observations. Both are plotted on an I(10830)/I(5876) vs I(5876)/I(4471) plane. It appears that the theory of helium triplet line strengths agrees with present observations, and that the question of an additional depopulation mechanism for the 2 3S population is probably predicted correctly within 30%
This contribution aims to present non-local thermodynamic Equilibrium (NLTE) modeling of hydrogen an...
We calculate the He I case B recombination cascade spectrum using improved radiative and collisional...
We present observations and models of the behaviour of the HI and HeI lines between 1.6 and 2.2um in...
Smits has recently calculated theoretical He I intensities for a large number of lines for condition...
We have combined the detailed He I recombination model of Smits with the collisional transitions of ...
Accurate and reliable helium abundances can test modern theories of galactic and primordial nucleosy...
We present the results of several collisional-radiative models describing optically thin emissivitie...
This paper describes a new determination of the primordial helium abundance (Y_P), based on the abun...
We apply a recently developed theoretical model of helium emission to observations of both the Orion...
Determinations of the primordial helium abundance are used in precision cosmological tests. These re...
We apply a recently developed theoretical model of helium emission to observations of both the Orion...
International audienceWe determine the primordial helium mass fraction Yp using 93 spectra of 86 low...
Ever since its discovery the spectrum of helium has been thought to consist of singlets and doublets...
We have observed a large sample of compact planetary nebulae in the near-infrared to determine how t...
We present results from photoionization models of low-metallicity H II regions. These nebulae form t...
This contribution aims to present non-local thermodynamic Equilibrium (NLTE) modeling of hydrogen an...
We calculate the He I case B recombination cascade spectrum using improved radiative and collisional...
We present observations and models of the behaviour of the HI and HeI lines between 1.6 and 2.2um in...
Smits has recently calculated theoretical He I intensities for a large number of lines for condition...
We have combined the detailed He I recombination model of Smits with the collisional transitions of ...
Accurate and reliable helium abundances can test modern theories of galactic and primordial nucleosy...
We present the results of several collisional-radiative models describing optically thin emissivitie...
This paper describes a new determination of the primordial helium abundance (Y_P), based on the abun...
We apply a recently developed theoretical model of helium emission to observations of both the Orion...
Determinations of the primordial helium abundance are used in precision cosmological tests. These re...
We apply a recently developed theoretical model of helium emission to observations of both the Orion...
International audienceWe determine the primordial helium mass fraction Yp using 93 spectra of 86 low...
Ever since its discovery the spectrum of helium has been thought to consist of singlets and doublets...
We have observed a large sample of compact planetary nebulae in the near-infrared to determine how t...
We present results from photoionization models of low-metallicity H II regions. These nebulae form t...
This contribution aims to present non-local thermodynamic Equilibrium (NLTE) modeling of hydrogen an...
We calculate the He I case B recombination cascade spectrum using improved radiative and collisional...
We present observations and models of the behaviour of the HI and HeI lines between 1.6 and 2.2um in...