Modelling and Simulations of Supernova Remnants

Modelling and Simulations of Supernova Remnants

XMM-Newton 2019 Science Workshop “Astrophysics of hot plasma in extended X-ray sources” 2019-06-12 European Space Astronomy Centre (ESAC), Madrid, Spain Modelling and simulations of supernova remnants Gilles Ferrand Research Scientist Astrophysical Big Bang Laboratory (ABBL) and Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS) + A. Decourchelle, S. Safi-Harb + S. Nagataki, D. Warren, M. Ono, F. Röpke, I. Seitenzhal Modelling and simulations of supernova remnants with a focus on morphological studies Introduction to SNRs Structure and evolution of a remnant Multi-wavelength emission 1. SNRs as particle accelerators Hydro-kinetic coupling for diffusive shock acceleration (DSA) Non-equilibrium ionization and thermal emission from the plasma Magnetic field amplification and non-thermal emission from the particles 2. SNRs as probes of the explosion From the supernova to the remnant: Cas A, Tycho Example: the N100 supernova model X-ray image analysis Supernova remnants 0.1 SNRs as a key link between stars and the ISM Tycho’s SNR age: ∼440 yr distance: 1.5–5 kpc enrichment in heavy elements size: 8’ ∼3–12 pc average stars: up to C-O massive stars: up to Fe supernovae: above Fe hot, turbulent metal-rich plasma injection of energy heating of the gas hydrodynamic turbulence magnetic field amplification multi- wavelength composite image: - X-rays acceleration (Chandra) of particles - Optical large, powerful (Calar Alto) shock wave most favoured Galactic sources - infrared 15 (Spitzer) up to the knee (< 10 eV) 0.2 Classification of SNRs from radio + X-ray observations SNR 0509-67.5 W49B G21.5-0.9 Crab Nebula shell composites filled-centre “mixed morphology” plerionic isolated/shell-less = thermal composite: composite (= non- pulsar wind nebula centrally peaked thermal composite): = PWN (= plerion) PWN inside shell or (can be both) bow shock nebula 0.3 The evolution of a supernova remnant radius R non-radiative radiative momentum-driven values given for pressure-driven 1.4 solar masses 46 pc of ejecta with kinetic energy of 1051 erg, expanding in a Sedov-Taylor medium of density 7 pc 0.1 cm-3 ejecta-dominated 600 yr 30 000 yr time t G1.9+0.3 Tycho RCW 86 Simeis 147 Monoceros Loop 140 yr 440 yr 2,000–10,000 yr ∼40,000 yr ∼300,000 yr 0.4 The structure of a young shell SNR Tycho’s SNR 0.95 – 1.26 keV 1.63 – 2.26 keV as seen by Chandra 4.10 – 6.10 keV at age 433 yr Warren et al 2005 0.5 SNR broad-band emission A&A 516, A62 (2010) SN 1006 Fig. 6. Azimuthal profile obtained from HESS data and XMM-Newton data in the 2–4.5 keV energy band and smoothed to HESS PSF, re- stricted to radii 0.12◦ r 0.36◦ from the centre of the SNR. Azimuth ≤ ≤ 0◦ corresponds to East, 90◦ corresponds to North, 180◦ to West and 90◦ to South. − radio optical X Fig. 4. HESS γ-ray image ofgamma SN 1006. The linear colour scale is in units 2 2 of excess counts per π (0.05◦) .Pointswithin(0.05◦) are correlated. The white cross indicates× the geometrical centre of the SNR obtained from XMM data as explained in the text and the dashed circlesE cor- respond to R dR as derived from the fit. The white star shows the centre of the circle± encompassing the whole X-ray emission as derived keV by Rothenflug et al. (2004) andTeV the white triangle the centre derived by cm µm Cassam-Chenaï et al. (2008) from Hα data. The white contours corre- spond to a constant X-ray intensity as derived from the XMM-Newton λ flux map and smoothed to the HESS point spread function, enclosing respectively 80%, 60%, 40% and 20% of the X-ray emission. The inset shows the HESS PSF using an integration radius of 0.05◦. synchrotron Balmer lines atomic lines of Inverse Compton ? in B field forbidden lines heavy elements pion decay ? Fig. 7. Differential energy spectra of SN 1006 extracted from the two + synchrotron regions NE and SW as defined in Sect. 2.Theshadedbandscorrespond to the range of the power-law fit, taking into account statistical errors. Table 2. Fit results for power-law fits to the energy spectra. Region Photon index ΓΦ(>1TeV) 12 2 1 (10− cm− s− ) NE 2.35 0.14stat 0.2syst 0.233 0.043stat 0.047syst SW 2.29 ± 0.18 ± 0.2 0.155 ± 0.037 ± 0.031 GeV e- blast wave hot ejecta > TeV e- ? ± stat ± syst ± stat ± syst Fig. 5. Radial profile around the centre of the SNR obtained from HESS data and XMM-Newton data in the 2–4.5 keV energy band smoothed to + TeV e- HESS PSF. > TeV p ? The spectra for the NE and SW regions are compatible with Γ power law distributions, F(E) E− ,withcomparablephoton indices Γ and fluxes. Confidence∝ bands for power-law fits are centred on 143.6◦ 6.1◦ (SW region) and 29.3◦ 4.0◦ (NE − ± ± shown in Fig. 7 and Table 2.Theintegralfluxesabove1TeV region) and with similar widths of 33.8◦ 7.0◦and 27.9◦ 4.0◦. ± ± correspond to less than 1% of the Crab flux, making SN 1006 reviews (high energies perspective): Reynolds 2008, Vink 2012 one of the faintest known VHE sources (Table 2). The derived 4. Spectral analysis fluxes are well below the previously published HESS upper lim- its (Aharonian et al. 2005). The observed photon index Γ 2.3is Differential energy spectra of the VHE γ-ray emission were de- somewhat steeper than generally expected from diffusive≈ shock rived for both regions above the energy threshold of 260 GeV. acceleration theory and may indicate that the upper cut-off of the These regions correspond to 80% of the X-ray emission∼ (after high-energy particle distribution is being observed; however, the smearing with the HESS PSF) and therefore slightly underesti- uncertainties on the spectrum preclude definitive conclusions on mate the TeV emission of the full remnant. this point. Page 4 of 7 SNRs as particle accelerators 1.1 Efficient particle acceleration SNRs are widely believed to be the main producers of CRs in the Galaxy • Available energy budget — but can we reach the knee? • Known acceleration mechanism — but what spectrum? • Observed energetic electrons — and protons? If CRs are efficiently accelerated by the blast wave, it must impact its dynamics - fluid becomes more compressible - energy leaks from the system → non-linearly coupled system CRs are a key ingredient of SNRs 1.2 Diffusive shock acceleration: the coupled system IR Opt radio UV X γ X shock wave cosmic-rays injection, acceleration (thermal magnetized (non-thermal shock modification plasma) population) conservation laws damping particle distribution: heating ∂X 2 +div(F (X)) = 0 n (x, t)= f (x, p, t)4πp dp ∂t Zp ρ ρu transport equation: X = ρu F (X)= ρu u + pI 0 1 0 ⌦ 1 ∂f ∂ ∂ ∂f 1 ∂p3f ∂u P (e + P ) u generationdiffusion, (instabilities) injection, + (uf)= D + 2 stochastic acceleration∂t ∂x ∂x ∂x 3p ∂p ∂x @ A @ A ✓ ◆ magnetic waves hydrodynamic (collective movements kinetic treatment of charges) treatment reviews on DSA : Drury 1983, Jones and Ellison 1991, Malkov and Drury 2001 on numerical techniques for DSA: Marcowith et al (in prep) 1.3 Numerical simulations: hydro + kinetic slice of log(density) Teyssier 2002, Chevalier 1982, 1983 Fraschetti et al 2010 SNR initialization: SNR evolution: self-similar profiles 3D hydro code from Chevalier ramses parameters: Tycho (SN Ia) tSN = 440 years shock back-reaction: 51 ESN = 10 erg diagnostics varying gamma n =7,Mej =1.4M Ellison et al 3 Ferrand et al 2010 s =0,n =0.1 cm− H,ISM 2007 (A&A 509 L10) particle acceleration: non-linear model of Blasi Blasi et al 2002, 2004, 2005 Anne + Caprioli 2008, 2009 Decourchelle Head of Astrophysics Dpt. Using a comoving grid to at CEA Saclay / Irfu factor out the expansion 1.11.4 Computing the emission from the SNR Thermal emission from the shocked plasma Samar Safi-Harb Prof. at the University of Manitoba test-particle case Canadian Research Chair Ferrand, Decourchelle, Safi-Harb 2012 Non-thermal emission from the accelerated particles modified shock Ferrand, Decourchelle, Safi-Harb 2014 with magnetic field amplification 1.5 Hydro- and thermodynamics of the plasma Thermal emission in each cell depends on: • plasma density n2 • electron temperature T e n progressive equilibration with protons temperature Tp via Coulomb interactions • ionization states fi(Z) Tp computation of non-equilibrium ionization - solving the coupled time-dependent system of equations Patnaude et al 2009, 2010 - using the exponentiation method ⌧ in post-processing I t slices at t = 500 yr from a 10243 simulation with particle τI = n(t0).dt0 back-reaction ZtS Smith & Hughes 2010 all these parameters depend on the history of the material after it was shocked. Ferrand, Decourchelle, Safi-Harb 2012 1.6 Thermal emission Ferrand, Decourchelle, Safi-Harb 2012 using an emission code adapted from Mewe, with rates from emissivity [erg/s/cm3/eV] Arnaud 1024^3 cells t = 500 yr energy [eV] test particle vs. back-reaction test particle vs. back-reaction test particle vs. back-reaction 1.7 Magnetic field and radiative losses Non-thermal emission in each cell depends on: • pion decay: plasma density n(x, t) • synchrotron: magnetic field B ( x, t) n (amplified at the shock, then frozen in the flow) • Compton: ambient photon fields (CMB) B Note: the acceleration model gives the CR spectra just behind the shock fp(p, x, t) ,fe(p, x, t) they must be transported to account for losses: slices at t = 500 yr from a ✓ 10243 simulation without ⇥(x, t) particle back-reaction • adiabatic decompression α = and MF amplification ⇥(xS,tS) t 2 1 • radiative losses Θ B α 3 dt / ZtS Ferrand, Decourchelle, Safi-Harb 2014 1.8 Non-thermal emission Ferrand, Decourchelle, Safi-Harb 2014 synchrotron (e) pion decay (p) using the emission code from P.

View Full Text

Details

  • File Type
    pdf
  • Upload Time
    -
  • Content Languages
    English
  • Upload User
    Anonymous/Not logged-in
  • File Pages
    34 Page
  • File Size
    -

Download

Channel Download Status
Express Download Enable

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

  • Not to be reproduced or distributed without explicit permission.
  • Not used for commercial purposes outside of approved use cases.
  • Not used to infringe on the rights of the original creators.
  • If you believe any content infringes your copyright, please contact us immediately.

Support

For help with questions, suggestions, or problems, please contact us