Progenitor signatures in Supernova Remnant Morphology. Jacco Vink Utrecht University

Transcription

1 Progenitor signatures in Supernova Remnant Morphology Jacco Vink Utrecht University

2 The evolution of SNRs Heating by two shocks: 1. forward shocks heating ISM/CSM 2. reverse shock heating ejecta radius Truelove & McKee (2000) forward shock Evolution forw./rev. shock determined by velocity/density structure ejecta structure of the CSM progenitor wind/no wind if wind: shell(s) may be present Reverse shock heat ejecta: -copious X-ray line emission from metals velocity reverse shock ejecta shock velocity 2

3 The evolution of SNRs Heating by two shocks: 1. forward shocks heating ISM/CSM 2. reverse shock heating ejecta radius Truelove & McKee (2000) forward shock Evolution forw./rev. shock determined by velocity/density structure ejecta structure of the CSM progenitor wind/no wind if wind: shell(s) may be present Reverse shock heat ejecta: -copious X-ray line emission from metals SNRs allow us to study both the supernova explosion properties and the progenitor wind properties velocity reverse shock ejecta shock velocity 2

4 Type Ia SNRs For young SNRs: typing through X-ray (or optical) line emission (e.g. Hughes ʼ95) Type Ia: often Fe-L dominated spectra (exception: SN1006) All identified Type Ia SNRs have Hα emission from the forward shock (Balmer dominated shock) Type Ia SNRs have a more spherical morphology then core collapse SNRs 3

5 Spectral identification N103B N Vink+ in preparation Dem L LMC SN Ia remnants green is Fe emission (Chandra) 4

6 Morphological dichotomy Lopez: Statistics based on the moments of the surface brightness distribution (Si XIII X-ray lines) Type Ia SNRs more spherical May be due to inherent asphericity of core collapse SNe Lopez+ ʼ09 5

7 SN 1006 & SNR SN1006 SNR (LMC) Both SNRs flattened on one side Best visible in outer (oxygen emitting) layer CSM effect Kosenko+ ʼ10 (Chandra) 6

8 SN 1006 & SNR SN1006 SNR (LMC) Both SNRs flattened on one side Best visible in outer (oxygen emitting) layer CSM effect Kosenko+ ʼ10 (Chandra) 6

9 SN 1006 & SNR SN1006 SNR (LMC) Oxygen band only Both SNRs flattened on one side Best visible in outer (oxygen emitting) layer CSM effect Kosenko+ ʼ10 (Chandra) 6

10 Balmer dominated shocks SN1604 SN1006 NE (LMC) Sankrit, Blair+ (HST) Raymond+ ʼ07 (HST) Hughes+, Helder+ (HST) Ghavamian+ (Clay Telescope) 7

11 The importance of Balmer lines Balmer dominated shocks require a (partially) neutral medium Core collapse SNRs: CSM ionized by progenitor or flash ionized Type Ia: presence of Balmer lines indicate small UV flux progenitor! (Ghavamian+ ʼ03) 4π 3 R3 n 2 H α B = L R ion = kT 1/3 L ergs 1 kt 50eV 1/3 Rappaport+ʼ94: HII regions of 30 pc expected Most SNRs discussed here: R~2-8 pc n H 1cm 3 2/3 pc 8

12 The importance of Balmer lines Balmer dominated shocks require a (partially) neutral medium Core collapse SNRs: CSM ionized by progenitor or flash ionized Type Ia: presence of Balmer lines indicate small UV flux progenitor! (Ghavamian+ ʼ03) 4π 3 R3 n 2 H α B = L R ion = kT 1/3 L ergs 1 kt 50eV 1/3 Rappaport+ʼ94: HII regions of 30 pc expected Most SNRs discussed here: R~2-8 pc Type Ia SNRs are inconsistent with SSS scenario! n H 1cm 3 2/3 pc 8

13 Wind blown cavities? In the SD scenario accretion needs to be finely balanced: dm/dt < 10-7 Msun/yr: unstable accretion -> NOVA explosions dm/dt > 10-6 Msun/yr: collapse into NS Remedy: stabilize accretion for > 10-6 Msun/yr with accretion wind (Hachisu+ ʼ96) Wind from WD will be fast (> 1000 km/s) Fast winds excavate large cavities (Badenes+ ʼ07) Han&Podsiadlowski ʼ04 Nomoto+ ʼ03 9

14 No evidence for cavities Badenes+ ʻ07 studied hydrodynamic effects of wind blown cavities on SNR morphology and X-ray spectroscopic properties: -shock velocity/radius vs age -ionization structure vs age HP3=Han&Podsiadlowski ʼ04;L2=Langer 10

15 No evidence for cavities Badenes+ ʻ07 studied hydrodynamic effects of wind blown cavities on SNR morphology and X-ray spectroscopic properties: -shock velocity/radius vs age -ionization structure vs age HP3=Han&Podsiadlowski ʼ04;L2=Langer 10

16 The curious case of Keplerʼs SNR Historical SNR of SN1604 High above Gal. plane: 590d 5 pc Distance 3-7 kpc (!) High velocity progenitor: V prog~250 km/s NW: interaction with dense, N-rich, shell Typing SN1604: Before ~1980ies: SN1604 was a Type I 1985-~1995: SN1604 was a Type Ib (runaway star, Bandiera ʼ88) after1999: X-rays: Type Ia (Kinugasa&Tsunemi ʻ99, Reynolds+ ʼ07) Reynolds+ ʼ07 11

17 Interaction with CSM Radio and X-ray expansion measurements (Dickel+ ʼ88, Vink ʼ08, Katsuda+ ʼ08): -Expansion parameter m: -Expected: Sedov m=0.4 n=7 Chevalier model m=0.7 -Kepler: SW-SE m= N-NE m=0.35 Implication: in N/NE SNR collides with a shell of about 1 Msun (Vink ʼ08) If E kin>1 foe: distance >~6 kpc R t m 12

18 Hydrosimulations 1 M sun shell implies non-conservative accretion Nitrogen rich shell: possibly implies 4-5 M sun AGB progenitor (dredge up of hot-bottom-burning process) Hydrosimulations: Chiotellis, Schure, Vink (cf. Borkowski+ʼ94): Assume Myr mass loss phase dm/dt ~ 10-5 Msun/yr Mlost~ 4 Msun code: AMRVAC (Keppens et al.) Size of shell depends on equilibrium P wind=pism - vism=250 km/s - nism=10-3 cm -3 - allow for variation to accommodate 4-6 kpc distance 13

19 Hydrosimulations Shell development Expansion parameter m reproduces expansion confirm long distance (~6 kpc) if E>1foe 4 kpc: 0.2 foe mass loss rates Msun/yr Mass loss must haven taken place for ~0.1-1Myr (flow time) fine tuning: has shock broken through shell? 14

20 Hydrosimulations Shell development Expansion parameter m reproduces expansion confirm long distance (~6 kpc) if E>1foe 4 kpc: 0.2 foe mass loss rates Msun/yr Mass loss must haven taken place for ~0.1-1Myr (flow time) fine tuning: has shock broken through shell? 14

21 Hydrosimulations Shell development Expansion parameter m reproduces expansion confirm long distance (~6 kpc) if E>1foe 4 kpc: 0.2 foe mass loss rates Msun/yr Mass loss must haven taken place for ~0.1-1Myr (flow time) fine tuning: has shock broken through shell? Mass loss required: favors SD scenario (?) 14

22 Do more Type Ia SNRs have shells? DEM L238/DEM L239: dense Fe cores (XMM/Chandra, Borkowski+06) Requires early development of reverse shock Perhaps facilitated by wind shells Overall local ISM density low 15

23 Tychoʼs SNR (SN1572) Issue: ejecta close too close to shock Conventional explanation (Warren+ 05): cosmic ray acceleration-> higher compression ratios Possible alternative: recent encounter with shell (c.f. Kosenko+ ʻ10) Caveat: difficult to distinguish shell from random cloud encounters 16

24 Tychoʼs SNR (SN1572) Issue: ejecta close too close to shock Conventional explanation (Warren+ 05): cosmic ray acceleration-> higher compression ratios Possible alternative: recent encounter with shell (c.f. Kosenko+ ʻ10) Caveat: difficult to distinguish shell from random cloud encounters 16

25 Wrapping up No evidence for fast, energetic winds (WD accretion winds) Evidence for shells from slow winds: secondary evolved star? (Kepler: 4-5 Msun AGB star-> nitrogen richness) (Partial) neutral medium: No supersoft sources (or low duty cycle-> di Stefano) Could slow winds absorb most of the UV/X-ray radiation? 17

26 Conclusions Type Ia SNRs are excellent objects to study Ia explosions + CSM No evidence for ionized bubbles (no naked SSSs) No evidence for fast accretion winds (lack of cavities) Ia SNRs are well behaved (spherical explosions/csm) At least one object (Kepler/SN1604) shows evidence for slow wind/ non-conservative mass accretion Carlesʼ talk: X-ray spectra of Type Ia SNRs are well reproduced by M Ch 1D DDT models (except maybe the spatial distribution of Ca). This can be used to determine the SN Ia subtype (dim/bright 56 Ni Fe). The key advantage of SNRs is the ability to study the environment: CSM + Resolved stellar populations. 18

27 Historical lightcurve Colors: initially like Mars day eight like Jupiter (Baade 1943) 19