Supernova Remnant Dynamics: Opportunities for Astro-H

1. Supernova Remnant Dynamics: Opportunities for Astro-H Knox S. Long, AyaBamba And SNR Dynamics WPT

2. Why observe SNRs with Astro-H – Science • SNRs are particle accelerators and sources of cosmic rays and high energy gamma rays that we do not understand well • SNRs are an important part of the life cycle of stars and affect how galaxies evolve • Source of energy and heavy elements that stirs and mixes the ISM • The Fe in our bodies came to us via Ia SN explosions and the distribution and reassembly of the material into the solar system and our bodies • SNRs contain young pulsars and pulsar wind nebulae and we would like to understand the physics of these objects and the particles they acclerate • SNRs are probes for understanding SN explosions • Elemental abundances allow us to determine the type of a SN • Distribution of material has implications for the explosion process • Astrophysical laboratory that cannot be duplicated on earth • Shock physics • Plasma processes

3. Astro-H strengths and weaknesses for SNRs • Strengths • Outstanding spectral resolution (4-6 eV) • Doppler tomography • Global structure of the ejecta • Kinematic determination of in temperatures • Allows isolation of lines for detailed line diagnostics • New ion and better evaluation of many more ion species • Constraints on nature of explosion, abundances of mass and of ejecta • Search for ejecta in older objects • Broad energy band coverage with high spectral resolution • Cleaner separation of thermal and non-thermal components • Studies of cosmic ray pressure mediated shocks • Identification of thermal continua, e.g recombination • Weaknesses • Spatial resolution (compared to Chandra and XMM) • Hard to isolate different regions of SNRs • Global modeling of SNR spectra will be extremely complicated

4. Scope of the SNRs dynamics WPT • There are many aspects of SNR research that can be carried out with Astro-H • In our initial discussions the SNR dynamics WPT has is concentrating on measurements that involve bulk velocities or velocity widths • But problems of understanding SNRs cannot easily be isolated from one another • Example – To attempt to use Astro H to separate the primary and reverse shock requires and understanding of abundances in the ejecta and ISM

5. What is SNR dynamics  Velocity and velocity widths • How can Astro-H be used to determine the 3-D structure of young SNRs? • Distribution and velocity structure of the ejecta and nature of SN explosions • Asymmetry of explosions from differences asymmetries in profile shapes and non-radial profile variations • Signature of the way the explosion proceeds by measuring velocity shifts between ions • Importance of instabilities in the expansion • Difference in velocities of different (forward and reverse shock) both through elemental abundances and velocity widths • Visual appearance suggests the forward and reverse shocks are not well resolved in young SNRs. • Use velocity structure to separate CSM, reverse shock, and forward shock • What can velocity widths measured with Astro H at shock front tell us about shock physics? • Bulk velocity measures shock speed and compression • Thermal widths provide direct measure of the temperature of post-shock gas without complicated atomic physics and the gas pressure for comparions with the total pressure

6. SNR dynamics (cont.) • Evolutionary state of SNRs • The actual evolutionary state of SNRs particularly, including mixed morphology objects like W28 and W49B is quite uncertain • Some are claimed to be cavity explosions or in other cases SNRs which have a strong interaction with a local ISM • Velocity structure of mixed morphology SNRs • Cavity explosions – fundamental question one would like to answer is how to determine how environment affects the appearance of a SNR. Mixed morphology SNRs are a prime example. Are they old or are they cavity explosions. Velocity structure might determine this • Direct velocity measurement of shock velocity at the center of a SNR plus measurement of proper motion of filaments at edge (x-ray/optical) provides a distance estimate • 3-d structure of old SNRs • Shock cloud interactions

7. Tycho’s SNR • In Tycho with Suzaku • The FWHM varies from 210 eV to 130 eV. • The center width due either • expansion of the shell, or • changes in the temperature with R • The edge is broader than a simple NEI model --> TFe ~ 1-3 x 1010 K, which is roughly what one expects • In Tycho with Astro-H • Measure the velocity of the reverse shock • Probe radial distribution of material in the shock • Measure the post-shock velocity of ions in the shell, providing independent measure of the ion temperature • May be able to measure the difference in velocity of forward and reverse shocks, depending on the structure • Astro-H will be dynamite for this problem Furusawa et al 2010 Si region - +-1000 km vs 0 km

8. Simulation of Tycho SNR spectrum

9. Kepler’s SNR • Of interest in part because of interaction with CSM which suggests a single degenerate origin • How does it differ from other Ia SNRs

10. SN1006 Schweitzer-Middledtich star - Si II 1260 A • SN1006 has been observed in absorption along at 3 lines of sight - SM star and two quasars • The center contains unshocked gas • The velocity of reverse shock is known • Astro-H observations of these lines of sight • Probe material at the reverse shock interface Yamguchi et al. 2009

12. Cas A and other core collapse SNRs • Delaney et al. have used Spitzer and CXO to produce a 3-d map of the SN • a spherical component, a tilted thick disk, and multiple ejecta jets/pistons and optical fast-moving knots all populating the thick disk plane. • Cas A • Size of 180” means that Astro-H can only resolve into a small number of elements. • Nevertheless largest and brightest core-collapse SN • Other objects, e. g. N132D and E102-70.3 also easily accessible to Astro-H • Essentially unresolved so will require modelling using Chandra or XMM-images to aid in the analysis

13. Puppis A

14. SN 1987A • Dewey et al. (2008) analysis of HETG data show lower than expected bulk velocities (300-700 km s-1) and deceleration since earlier LETG • Velocity widths are broader than expected • Expansion velocity of ring inferred from spectra much less than the expansion velocity of ring in X-ray image

15. Other young SNe and their intercation with the CSM • NGC4449 almost impossible to analyze at existing spectral resolution, but could be observed more effectively with Astor H • SN1996cr with HETG 489 ks in 2009 is an example of a young SN for which a spectrum could be obtained to measure both the nature of the interaction with the CSM and abundances in the ejecta

16. Topics not addressed here, but which some WPT should include • Determining what type of SN explosion caused a SNR • Fundamental issue for establishing how SN interact with their environment. Particularly important for middle aged SNRs • Can we confirm the basics of the delayed detonation model which argues that Ni mass is the primary discriminator in SN light Light echoes and X-ray spectra • 0509-67.5 in LMC a luminous 1a • Tycho a normal 1a • Can we confirm that RCW86 is a Ia explosion in a cavity • Can we confirm Pre-SN metallicity from Mn/Cr ratio • Direct detection of SN ejecta including masses of the biproducts • Use velocity information to inform modles

17. What is needed to make these observations possible with Astro-H • Best energy resolution possible to measure broadening of lines, particularly of low z ions • Accurate energy calibration to enable to measure velocity shifts accurately • Best point spread function possible with as simple a structure as possible • Excellent knowledge of point spread function to enable modeling of effect of spatial resolution models on knowledge