Impact of the ERF on the structure and evolution of SNRs
| Autor: | Jan Palouš, Yago Ascasibar, Mercedes Mollá, Richard Wünsch, M. Romero |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
Range (particle radiation) Hydrogen Field (physics) Thermodynamic equilibrium Astrophysics::High Energy Astrophysical Phenomena chemistry.chemical_element Astronomy and Astrophysics Isothermal process Luminosity chemistry Space and Planetary Science Absorption (logic) Atomic physics Supernova remnant |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 505:5301-5310 |
| ISSN: | 1365-2966 0035-8711 |
| Popis: | We carry out 1D hydrodynamical simulations of the evolution of a spherically symmetric supernova remnant (SNR) subject to an external radiation field (ERF) that influences the cooling and heating rates of the gas. We consider homogeneous media with ambient hydrogen number densities $n_{\rm H,0}$ of $0.1$ and $1$ cm$^{-3}$ permeated by an average radiation field including the cosmic microwave, extragalactic, and Galactic backgrounds, attenuated by an effective column density $N_{\rm H,eff}$ from $10^{18}$ to $10^{21}$~cm$^{-2}$. Our results may be classified into two broad categories: at low $N_{\rm H,eff}$, the ERF presents little absorption in the ultraviolet (ionising) regime, and all the 'unshielded' cases feature an equilibrium temperature $T_{eq} \sim 7000$~K below which the ambient gas cannot cool further. In this scenario, the SNR develops a nearly isothermal shock profile whose shell becomes thicker over time. At higher $N_{\rm H,eff}$, the ERF is heavily absorbed in the UV range, yielding a roughly constant heating function for temperatures $\lesssim 10^4$ K. These `shielded' cases develop a thin, cold and dense shell throughout their evolution. Energy and momentum injection to the medium do not change significantly between both scenarios, albeit luminosity is higher and more uniformly distributed over the shell for unshielded SNR. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|