<i>Physical Processes in the Interstellar Medium</i>

Spitzer, Lyman

doi:10.1063/1.2995108

Cited by 1,893 publications

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“…where σ inst = 43.5 km s −1 , σ th = 9.1 km s −1 for hydrogen gas at T e = 10 4 (Spitzer 1978) and σ intrin = 3 km s −1 for the fine structure of the Hα line. Some authors also refer to σ corr as the turbulent velocity dispersion.…”

Section: Kinematics Of the H II Regions In Ic 1613mentioning

confidence: 99%

Kinematics of the ionized gas in the Local Group irregular galaxy IC 1613

Valdez-Gutiérrez

Rosado

Георгиев

et al. 2001

A&A

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Abstract. We present Hα and [S ii] observations for the Local Group irregular galaxy IC 1613 using the PUMA scanning Fabry-Perot interferometer. Our goal is to analyze the kinematics of the ionized gas in the complex sample of superbubbles located in the whole extension of our field (10 ), which includes most of the optical emission of this galaxy, and to study the inter-relationship between young stellar associations and nebulae based on a previous study that we have made on the stellar associations of the central region of this galaxy. The ionized gas in this galaxy is distributed in classical H ii regions and in a series of superbubbles (also called giant shells) covering a large fraction of the optical extent of the galaxy. We present a catalog of kinematical properties of both the H ii regions of this galaxy and the superbubbles. We have also compared the kinematics of the ionized gas in H ii regions to search for possible dynamic differences between neutral and ionized gas.

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Section: Kinematics Of the H II Regions In Ic 1613mentioning

confidence: 99%

Kinematics of the ionized gas in the Local Group irregular galaxy IC 1613

Valdez-Gutiérrez

Rosado

Георгиев

et al. 2001

A&A

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“…The initial ionization fraction of gas is set equal to zero. We used the recombination rate given by Spitzer (1978) and the collisional ionization in Cen (1992).…”

Section: Initial Conditionsmentioning

confidence: 99%

The simulated 21 cm signal during the epoch of reionization: full modeling of the Ly-αpumping

Baek¹,

Matteo

Semelin³

et al. 2008

A&A

107

146

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The 21 cm emission of neutral hydrogen is the most promising probe of the epoch of reionization (EoR). In the next few years, the SKA pathfinders will provide statistical measurements of this signal, such as its power spectrum. Within one decade, SKA should produce a full tomography of the signal. Numerical simulations predicting these observations are necessary to optimize the design of the instruments and help in the interpretation of the data. Simulations are reaching a reasonable level in terms of scale range, but still often rely on simplifications to compute the strength of the signal. The main difficulty is the computation of the spin temperature of neutral hydrogen which depends on the gas kinetic temperature and on the level of the local Lyman-α flux (The Wouthuysen-Field effect). A T S T CMB assumption is usual. However, this assumption does not apply early in the reionization history, or even later in the history as long as the sources of X-rays are too weak to heat the intergalactic medium significantly. This work presents the first EoR numerical simulations including, beside dynamics and ionizing continuum radiative transfer, a self-consistent treatment of the Ly-α radiative transfer. This allows us to compute the spin temperature more accurately. We use two different box sizes, 20 h −1 Mpc and 100 h −1 Mpc, and a star source model. Using the redshift dependence of average quantities, maps, and power spectra, we quantify the effect of using different assumptions to compute the spin temperature and the influence of the box size. The first effect comes from allowing for a signal in absorption (i.e. not making the T S T CMB approximation). The magnitude of this effect depends on the amount of heating by hydrodynamic shocks and X-rays in the intergalactic medium (IGM). With our source model we have little heating so regions seen in absorption survive almost until the end of reionization. The second effects comes from using the real, local, Lyman-α flux. This effect is important for an average ionization fraction of less than ∼10%: it changes the overall amplitude of the 21 cm signal, and adds its own fluctuations to the power spectrum.

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“…As for the photoionization process, we employ the on-the-spot approximation (Spitzer 1978) which has already been discussed in section 1. We solve the transfer of ionizing photons directly from the source, whereas we do not solve the transfer of diffuse photons.…”

Section: Brief Description Of the Codementioning

confidence: 99%

SPH Radiative Hydrodynamics Methods

Susa

2010

Proc. IAU

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Abstract. In this paper, we review the radiative hydrodynamics methods based upon Smoothed Particle Hydrodynamics(SPH). There are already various implementations so far, which can be categorized into three types: moment equation solvers, Monte Carlo methods, and ray-tracing schemes. These codes have been applied to various astrophysical problems including dynamics of dense proto-stellar cores, photoionization feedback of massive stars on molecular clouds, radiative feedback in the early universe, etc. Among these different methods, we focus on the ray-tracing schemes. We also describe one particular ray-tracing code RSPH in some details.

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Physical Processes in the Interstellar Medium

Cited by 1,893 publications

References 0 publications

Kinematics of the ionized gas in the Local Group irregular galaxy IC 1613

Kinematics of the ionized gas in the Local Group irregular galaxy IC 1613

The simulated 21 cm signal during the epoch of reionization: full modeling of the Ly-αpumping

SPH Radiative Hydrodynamics Methods

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