Time-dependent quantum theory I. An absorber in an intense radiation field

1971 ◽  
Vol 5 (1) ◽  
pp. 13-34 ◽  
Author(s):  
J. M. Schurr
Keyword(s):  
Quantum Theory ◽  
Radiation Field ◽  
Time Dependent ◽  
Intense Radiation

Tight-binding Electron-ion Dynamics: A Method for treating nonadiabatic processes and Interactions with Electromagnetic Radiation

1997 ◽  
Vol 491 ◽  
Author(s):  
J. S. Graves ◽  
R. E. Allen
Keyword(s):  
Electromagnetic Radiation ◽  
Radiation Field ◽  
Schrodinger Equation ◽  
Tight Binding ◽  
Time Dependent ◽  
Ion Dynamics ◽  
Coupled Dynamics ◽  
Electrons And Ions ◽  
Ehrenfest Theorem ◽  
Intense Radiation

ABSTRACTA method is introduced for simulations of the coupled dynamics of electrons and ions in a molecule or material. It is applicable to general nonadiabatic processes, including interactions with an arbitrarily intense radiation field. The field is included in the electronic Hamiltonian through a time-dependent Peierls substitution. The time-dependent Schrödinger equation is solved with an algorithm that preserves orthogonality, and the atomic forces are obtained from a generalized Ehrenfest theorem. Calculations for GaAs and Si demonstrate that the method is reliable and quantitative.

scholarly journals Circumstellar Disks around Young Solar-type Stars

2004 ◽  
Vol 219 ◽  
pp. 385-389 ◽  
Author(s):  
Inga Kamp ◽  
Fatima Sammar
Keyword(s):  
Radiation Field ◽  
Uv Radiation ◽  
Circumstellar Disks ◽  
Central Star ◽  
Time Dependent ◽  
Solar Chromosphere ◽  
Starting Point ◽  
Solar Type ◽  
Time Dependent Behaviour ◽  
Dependent Behaviour

The chemistry of circumstellar disks around young (a few 10 Myr) solar-type stars is mainly driven by the strong UV radiation field of the central star. As a starting point for a detailed UV radiation field, the rocket and satellite observations of the solar chromosphere are used and scaled according to the time-dependent behaviour of stellar activity. The disk chemistry as well as dust and gas temperatures are then derived self-consistently from the model. The results of these calculations can be used for the identification of the most promising gas tracers as well as for the interpretation of present and future observations.

scholarly journals MMT/MMIRS spectroscopy of z = 1.3 - 2.4 extreme [O iii] emitters: implications for galaxies in the reionization era

2019 ◽  
Vol 489 (2) ◽  
pp. 2572-2594 ◽  
Author(s):  
Mengtao Tang ◽  
Daniel P Stark ◽  
Jacopo Chevallard ◽  
Stéphane Charlot
Keyword(s):  
Star Formation ◽  
Radiation Field ◽  
Production Efficiency ◽  
Rest Frame ◽  
Optical Emission ◽  
Intense Line ◽  
Massive Galaxies ◽  
Stellar Masses ◽  
The Impact ◽  
Intense Radiation

ABSTRACT Galaxies in the reionization era have been shown to have prominent [O iii] + H β emission. Little is known about the gas conditions and radiation field of this population, making it challenging to interpret the spectra emerging at z ≳ 6. Motivated by this shortcoming, we have initiated a large MMT spectroscopic survey identifying rest-frame optical emission lines in 227 intense [O iii] emitting galaxies at 1.3 < z < 2.4. This sample complements the MOSDEF and KBSS surveys, extending to much lower stellar masses ($10^7\!-\!10^8 \, \mathrm{M}_\odot$) and larger specific star formation rates (5–300 Gyr−1), providing a window on galaxies directly following a burst or recent upturn in star formation. The hydrogen ionizing production efficiency (ξion) is found to increase with the [O iii] equivalent width (EW), in a manner similar to that found in local galaxies. We describe how this relationship helps explain the anomalous success rate in identifying Ly α emission in z ≳ 7 galaxies with strong [O iii] + H β emission. We probe the impact of the intense radiation field on the ISM using O32 and Ne3O2, two ionization-sensitive indices. Both are found to scale with the [O iii] EW, revealing extreme ionization conditions not commonly seen in older and more massive galaxies. In the most intense line emitters, the indices have very large average values (O32 = 9.1, Ne3O2 = 0.5) that have been shown to be linked to ionizing photon escape. We discuss implications for the nature of galaxies most likely to have O32 values associated with significant LyC escape. Finally we consider the optimal strategy for JWST spectroscopic investigations of galaxies at z ≳ 10 where the strongest rest-frame optical lines are no longer visible with NIRSpec.

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