Numerical simulations of high-energy flows in accreting magnetic white dwarfs
| Autor: | Jean-Marc Bonnet-Bidaud, Emeric Falize, Andrea Ciardi, C. Busschaert, Martine Mouchet, Lucile Van Box Som |
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| Přispěvatelé: | Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA (UMR_8112)), Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Direction des Applications Militaires ( DAM ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique ( LERMA ), École normale supérieure - Paris ( ENS Paris ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université de Cergy Pontoise ( UCP ), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique ( CNRS ), Département d'Astrophysique (ex SAP) ( DAP ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Laboratoire Univers et Théories ( LUTH ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), PSL Research University (PSL)-PSL Research University (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Shock wave
[ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph] Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astrophysics Parameter space 01 natural sciences Instability 010305 fluids & plasmas X-rays: binaries accretion 0103 physical sciences Radiative transfer 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) white dwarfs Physics High Energy Astrophysical Phenomena (astro-ph.HE) [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE] White dwarf Astronomy and Astrophysics shock waves Light curve accretion discs Accretion (astrophysics) Astrophysics - Solar and Stellar Astrophysics 13. Climate action Space and Planetary Science instabilities Polar Astrophysics - High Energy Astrophysical Phenomena [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
| Zdroj: | Monthly Notices of the Royal Astronomical Society Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2018, 473 (3), pp.3158-3168. ⟨10.1093/mnras/stx2557⟩ Mon.Not.Roy.Astron.Soc. Mon.Not.Roy.Astron.Soc., 2018, 473 (3), pp.3158-3168. 〈10.1093/mnras/stx2557〉 Mon.Not.Roy.Astron.Soc., 2018, 473 (3), pp.3158-3168. ⟨10.1093/mnras/stx2557⟩ Monthly Notices of the Royal Astronomical Society, 2018, 473 (3), pp.3158-3168. ⟨10.1093/mnras/stx2557⟩ |
| ISSN: | 0035-8711 1365-2966 |
| DOI: | 10.1093/mnras/stx2557⟩ |
| Popis: | Some polars show quasi-periodic oscillations (QPO) in their optical light curves which have been interpreted as the result of shock oscillations driven by the cooling instability. Although numerical simulations can recover this physics, they wrongly predict QPOs in the X-ray luminosity and have also failed to reproduce the observed frequencies, at least for the limited range of parameters explored so far. Given the uncertainties on the observed polar parameters, it is still unclear whether simulations can reproduce the observations. The aim of this work is to study QPOs covering all relevant polars showing QPOs. We perform numerical simulations including gravity, cyclotron and bremsstrahlung radiative losses, for a wide range of polar parameters, and compare our results with the astronomical data using synthetic X-ray and optical luminosities.We show that shock oscillations are the result of complex shock dynamics triggered by the interplay of two radiative instabilities. The secondary shock forms at the acoustic horizon in the post-shock region in agreement with our estimates from steady-state solutions. We also demonstrate that the secondary shock is essential to sustain the accretion shock oscillations at the average height predicted by our steady-state accretion model. Finally, in spite of the large explored parameter space, matching the observed QPO parameters requires a combination of parameters inconsistent with the observed ones. This difficulty highlights the limits of one-dimensional simulations, suggesting that multi-dimensional effects are needed to understand the non-linear dynamics of accretion columns in polars and the origins of QPOs. 12 pages, 8 figure, accepted in MNRAS |
| Databáze: | OpenAIRE |
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