High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Jacco Vink SRON National Institute for Space Research The Netherlands High Resolution X-ray Spectroscopy of SN 1006

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Supernova Remnant & Plasma Physics X-rays from SNRs are interesting for many reasons: ● Studying the supernova phenomenon: - nucleosynthesis (bulk mass visible in X-rays, alpha elements) - explosion energy and asymmetries ● Studying the interaction with the CSM/ISM ● Studying plasma/shock physics: - high Mach number collisionless shocks - cosmic ray acceleration (prime sources up to eV?) - influence of cosmic rays on plasma (energy drain) - physics of hot, thin plasmas ● Knowledge of plasma physics is a prerequisite for point 1

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Physics of SNR Plasmas ● Plasmas are very tenuous, typically 1 cm -3 ● SNR plasma are young ~10 – yr ● Result: number of collisions between particles has been low! ● Two main consequences: - Plasmas are generally not in ionization equilibrium (it is in the process of being ionized) electron temperature and ionization out of synch! presence of satellite lines/inner shell ionization (ions in low ionization states/electrons energetic enough to knock out K-shell electron, while L, M shell electrons present) - Plasma constituents may not be in temperature equilibrium ● Important question: How come the plasma is heated at the shock front in the 1 st place? Answer: plasma waves

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Non-Equilibrium Ionization (NEI) log n e t = Collision Ionization Equilibrium NEI SN 1006 Tycho (oxygen) Cas A He-like

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Temperature Non-equilibration Simplified plane parallel shock model, no equilibration: Electrons Protons Question: Is collisionless heating accompanied by instantaneous temperature equilibration (T e =T p ), or not? For strong shock, neglecting cosmic ray sinks: kT i = 2(γ-1)(γ+1) -2 mi v s 2 = 3/16 m i v s 2 (for γ =5/3)

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov ● young (~1000 yr) and low density (0.1 ions/cc) ionization and equilibration scale with n e t for SN 1006 ~ 3 x 10 9 cm -3 s cf Cas A n e t > cm -3 s (ionization and temperature equilibrium n e t > cm -3 s) ● Optical/ UV spectroscopy indicates temperature non-equilibration (Laming et al. 1996; Ghavamian et al 2002) ● High Mach shock: >3000 km/s ● Interesting historical, supernova remnant Why SN1006?

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov SN 1006 aka G (NB high latitude!): ● bright (<-6 mag) “ guest star” in AD 1006 recorded in Middle East, Asia & Europe ● likely to be Type Ia (but lack of observed Fe) ● distance 2.1 kpc (Ghavamian et al. 2002, Winkler et al. 2002) ● 30 arcmin diameter ● Average velocity 9375 km/s ● Absorption column: N H ~7 x cm -2 ● First shell remnant for which X-ray synchrotron emission was established (Koyama et al. 1995) SN 1006 some background

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov XMM-Newton's Reflection Grating Specrometers (RGS) - Three telescopes - Two gratings - No slit, spectral degradation: Δλ = 0.124( Δφ/1') Å

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Target Knot size < 1 arcmin (0.4 arcmin FWHM) Spectral resolution for bright lines e.g OVII (~22Å): > 1/170 Observational Strategy

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov RGS Spectrum O VII He α (triplet) NVI He α (triplet) NVI He β NVI He γ,δ?! O VII He β OVIII Lyα He γ He δ,ε.. Ne VI/VII N VII Ly β NB No bright Fe XVII lines Å)

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Low charge state of neon Ne Kα (RGS 2 order 1) measured centroid / Å cf Ne IX w : Å, z :13.70 Å So not in Ne IX like state or unusually large f/r ratio

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Single temperature NEI model OVII Ne Mg Si OVII/O VIII ● n e t = 2.4 x10 9 cm -3 s ● kT e = 1.5 ±0.2 keV ● OVII dominated ● Si ab. > 2 x solar EPIC (CCD) spectra Si Ka Kα lines support low ionization parameter: Mg 1.33 ± 0.01 keV (cf keV MgXI) Si 1.80 ±0.01 keV (vs 1.85 keV Si XIV)

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Constraining NEI

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov The OVII Thermal Broadening No rapid equilibration of electron, proton and oxygen temperature!! Results on line dispersion : ( Å, Chandra profile) σ E = 3.4±0.5 eV kT OVII = 528 ± 150 keV (6x10 9 K) v s ~ 4000 km/s Statistical confidence : 6.5–9.8 σ

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov OVII higher order lines Fits well with n > 2 to n=1 intensities following oscillator strengths Dominated by He α (some Lyα) He β/He α = 0.18 expected 0.20 OVII G-ratio ~ 1

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov The Spectrum of the Eastern Rim Hopeless for the RGS or perhaps not? Pointing

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov O VII triplet spectrum Shifted Over prediction ● Best fit shell velocity: 6010 ± 1227 km/s (90% conf) ● Foreground shell dominates (~65%) ● No large thermal broadening required ● Inferred He-triplet ratio: G ~ 0.9 The Shell Velocity of SN 1006

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov O VII He-like triplet Based on rates calculated by M. Gu

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Summary ● XMM's RGS allows high resolution spectroscopy of ~1 arcmin sized objects, or larger if small details are present ● Many lines resolved that cannot be seen in CCD spectra, e.g. N VI,O VII n=4,5,6 -> n=1 ● No evidence for FeL lines, due to low ionization ● Plasma far out of ionization equilibration: n e t ~ 2 x 10 9 cm -3 s ● CCD/RGS spectra: K line not always from He-like ionization state (Ne, Mg, Si), but due to inner shell processes ● Slow temp. equilibration of electrons and ions in NW: kT e ~ 1.5 keV and kT OVII ~ 500 keV ● Evidence for 6000 km/s shell velocity in East Results published in: J. Vink, J.M. Laming, M.F. Gu, A. Rasmussen, J. S. Kaastra Astrophysical Journal Letters 587, L31 (2003)

High Resolution X-ray Spectroscopy of SN 1006 X-ray Diagnostics of Astrophysical Plasmas Jacco Vink (SRON Nat. Inst. for Space Research) Cambridge Ma, Nov Ne He α OVII He γ,δ,.. OVII Heα OVII Heβ, OVIII Ly α NVI Heβ, NVII Ly α Other? NVI Heα (CVI Lyβ) NB no bright Fe lines! RGS Spectra Pulse height (energy) Dispersion (wavelength) (Expected Fe XVII)